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Fields L, Vu NQ, Dang TC, Yen HC, Ma M, Wu W, Gray M, Li L. EndoGenius: Optimized Neuropeptide Identification from Mass Spectrometry Datasets. J Proteome Res 2024; 23:3041-3051. [PMID: 38426863 PMCID: PMC11296898 DOI: 10.1021/acs.jproteome.3c00758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Neuropeptides represent a unique class of signaling molecules that have garnered much attention but require special consideration when identifications are gleaned from mass spectra. With highly variable sequence lengths, neuropeptides must be analyzed in their endogenous state. Further, neuropeptides share great homology within families, differing by as little as a single amino acid residue, complicating even routine analyses and necessitating optimized computational strategies for confident and accurate identifications. We present EndoGenius, a database searching strategy designed specifically for elucidating neuropeptide identifications from mass spectra by leveraging optimized peptide-spectrum matching approaches, an expansive motif database, and a novel scoring algorithm to achieve broader representation of the neuropeptidome and minimize reidentification. This work describes an algorithm capable of reporting more neuropeptide identifications at 1% false-discovery rate than alternative software in five Callinectes sapidus neuronal tissue types.
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Affiliation(s)
- Lauren Fields
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Nhu Q. Vu
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Tina C. Dang
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705, USA
| | - Hsu-Ching Yen
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Min Ma
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705, USA
| | - Wenxin Wu
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Mitchell Gray
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705, USA
- Lachman Institute for Pharmaceutical Development, School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, USA
- Wisconsin Center for NanoBioSystems, School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, USA
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2
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Castro DC, Chan-Andersen P, Romanova EV, Sweedler JV. Probe-based mass spectrometry approaches for single-cell and single-organelle measurements. MASS SPECTROMETRY REVIEWS 2024; 43:888-912. [PMID: 37010120 PMCID: PMC10545815 DOI: 10.1002/mas.21841] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 02/09/2023] [Accepted: 03/01/2023] [Indexed: 06/19/2023]
Abstract
Exploring the chemical content of individual cells not only reveals underlying cell-to-cell chemical heterogeneity but is also a key component in understanding how cells combine to form emergent properties of cellular networks and tissues. Recent technological advances in many analytical techniques including mass spectrometry (MS) have improved instrumental limits of detection and laser/ion probe dimensions, allowing the analysis of micron and submicron sized areas. In the case of MS, these improvements combined with MS's broad analyte detection capabilities have enabled the rise of single-cell and single-organelle chemical characterization. As the chemical coverage and throughput of single-cell measurements increase, more advanced statistical and data analysis methods have aided in data visualization and interpretation. This review focuses on secondary ion MS and matrix-assisted laser desorption/ionization MS approaches for single-cell and single-organelle characterization, which is followed by advances in mass spectral data visualization and analysis.
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Affiliation(s)
- Daniel C. Castro
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Peter Chan-Andersen
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Elena V. Romanova
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Jonathan V. Sweedler
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL USA
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Phetsanthad A, Vu NQ, Yu Q, Buchberger AR, Chen Z, Keller C, Li L. Recent advances in mass spectrometry analysis of neuropeptides. MASS SPECTROMETRY REVIEWS 2023; 42:706-750. [PMID: 34558119 PMCID: PMC9067165 DOI: 10.1002/mas.21734] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 08/22/2021] [Accepted: 08/28/2021] [Indexed: 05/08/2023]
Abstract
Due to their involvement in numerous biochemical pathways, neuropeptides have been the focus of many recent research studies. Unfortunately, classic analytical methods, such as western blots and enzyme-linked immunosorbent assays, are extremely limited in terms of global investigations, leading researchers to search for more advanced techniques capable of probing the entire neuropeptidome of an organism. With recent technological advances, mass spectrometry (MS) has provided methodology to gain global knowledge of a neuropeptidome on a spatial, temporal, and quantitative level. This review will cover key considerations for the analysis of neuropeptides by MS, including sample preparation strategies, instrumental advances for identification, structural characterization, and imaging; insightful functional studies; and newly developed absolute and relative quantitation strategies. While many discoveries have been made with MS, the methodology is still in its infancy. Many of the current challenges and areas that need development will also be highlighted in this review.
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Affiliation(s)
- Ashley Phetsanthad
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Nhu Q. Vu
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Qing Yu
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705, USA
| | - Amanda R. Buchberger
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Zhengwei Chen
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Caitlin Keller
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705, USA
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4
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Sivanich MK, Gu T, Tabang DN, Li L. Recent advances in isobaric labeling and applications in quantitative proteomics. Proteomics 2022; 22:e2100256. [PMID: 35687565 PMCID: PMC9787039 DOI: 10.1002/pmic.202100256] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 05/21/2022] [Accepted: 06/07/2022] [Indexed: 12/30/2022]
Abstract
Mass spectrometry (MS) has emerged at the forefront of quantitative proteomic techniques. Liquid chromatography-mass spectrometry (LC-MS) can be used to determine abundances of proteins and peptides in complex biological samples. Several methods have been developed and adapted for accurate quantification based on chemical isotopic labeling. Among various chemical isotopic labeling techniques, isobaric tagging approaches rely on the analysis of peptides from MS2-based quantification rather than MS1-based quantification. In this review, we will provide an overview of several isobaric tags along with some recent developments including complementary ion tags, improvements in sensitive quantitation of analytes with lower abundance, strategies to increase multiplexing capabilities, and targeted analysis strategies. We will also discuss limitations of isobaric tags and approaches to alleviate these restrictions through bioinformatic tools and data acquisition methods. This review will highlight several applications of isobaric tags, including biomarker discovery and validation, thermal proteome profiling, cross-linking for structural investigations, single-cell analysis, top-down proteomics, along with applications to different molecules including neuropeptides, glycans, metabolites, and lipids, while providing considerations and evaluations to each application.
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Affiliation(s)
| | - Ting‐Jia Gu
- School of PharmacyUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | | | - Lingjun Li
- Department of ChemistryUniversity of Wisconsin‐MadisonMadisonWisconsinUSA,School of PharmacyUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
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5
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A novel graphene oxide/chitosan foam incorporated with metal–organic framework stationary phase for simultaneous enrichment of glycopeptide and phosphopeptide with high efficiency. Anal Bioanal Chem 2022; 414:2251-2263. [DOI: 10.1007/s00216-021-03861-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/07/2021] [Accepted: 12/20/2021] [Indexed: 01/07/2023]
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6
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Multiplexed quantitative neuropeptidomics via DiLeu isobaric tagging. Methods Enzymol 2022; 663:235-257. [DOI: 10.1016/bs.mie.2021.10.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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7
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Inter-platform assessment of performance of high-throughput desorption electrospray ionization mass spectrometry. TALANTA OPEN 2021. [DOI: 10.1016/j.talo.2021.100046] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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8
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Jiang Z, Lietz CB, Podvin S, Yoon MC, Toneff T, Hook V, O’Donoghue AJ. Differential Neuropeptidomes of Dense Core Secretory Vesicles (DCSV) Produced at Intravesicular and Extracellular pH Conditions by Proteolytic Processing. ACS Chem Neurosci 2021; 12:2385-2398. [PMID: 34153188 PMCID: PMC8267839 DOI: 10.1021/acschemneuro.1c00133] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
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Neuropeptides mediate
cell–cell signaling in the nervous
and endocrine systems. The neuropeptidome is the spectrum of peptides
generated from precursors by proteolysis within dense core secretory
vesicles (DCSV). DCSV neuropeptides and contents are released to the
extracellular environment where further processing for neuropeptide
formation may occur. To assess the DCSV proteolytic capacity for production
of neuropeptidomes at intravesicular pH 5.5 and extracellular pH 7.2,
neuropeptidomics, proteomics, and protease assays were conducted using
chromaffin granules (CG) purified from adrenal medulla. CG are an
established model of DCSV. The CG neuropeptidome consisted of 1239
unique peptides derived from 15 proneuropeptides that were colocalized
with 64 proteases. Distinct CG neuropeptidomes were generated at the
internal DCSV pH of 5.5 compared to the extracellular pH of 7.2. Class-specific
protease inhibitors differentially regulated neuropeptidome production
involving aspartic, cysteine, serine, and metallo proteases. The substrate
cleavage properties of CG proteases were assessed by multiplex substrate
profiling by mass spectrometry (MSP-MS) that uses a synthetic peptide
library containing diverse cleavage sites for endopeptidases and exopeptidases.
Parallel inhibitor-sensitive cleavages for neuropeptidome production
and peptide library proteolysis led to elucidation of six CG proteases
involved in neuropeptidome production, represented by cathepsins A,
B, C, D, and L and carboxypeptidase E (CPE). The MSP-MS profiles of
these six enzymes represented the majority of CG proteolytic cleavages
utilized for neuropeptidome production. These findings provide new
insight into the DCSV proteolytic system for production of distinct
neuropeptidomes at the internal CG pH of 5.5 and at the extracellular
pH of 7.2.
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Affiliation(s)
- Zhenze Jiang
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Christopher B. Lietz
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Sonia Podvin
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Michael C. Yoon
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Thomas Toneff
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Vivian Hook
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
- Department of Neuroscience and Department of Pharmacology, University of California, San Diego, La Jolla, California 92093, United States
| | - Anthony J. O’Donoghue
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
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Sauer CS, Phetsanthad A, Riusech OL, Li L. Developing mass spectrometry for the quantitative analysis of neuropeptides. Expert Rev Proteomics 2021; 18:607-621. [PMID: 34375152 PMCID: PMC8522511 DOI: 10.1080/14789450.2021.1967146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/09/2021] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Neuropeptides are signaling molecules originating in the neuroendocrine system that can act as neurotransmitters and hormones in many biochemical processes. Their exact function is difficult to characterize, however, due to dependence on concentration, post-translational modifications, and the presence of other comodulating neuropeptides. Mass spectrometry enables sensitive, accurate, and global peptidomic analyses that can profile neuropeptide expression changes to understand their roles in many biological problems, such as neurodegenerative disorders and metabolic function. AREAS COVERED We provide a brief overview of the fundamentals of neuropeptidomic research, limitations of existing methods, and recent progress in the field. This review is focused on developments in mass spectrometry and encompasses labeling strategies, post-translational modification analysis, mass spectrometry imaging, and integrated multi-omic workflows, with discussion emphasizing quantitative advancements. EXPERT OPINION Neuropeptidomics is critical for future clinical research with impacts in biomarker discovery, receptor identification, and drug design. While advancements are being made to improve sensitivity and accuracy, there is still room for improvement. Better quantitative strategies are required for clinical analyses, and these methods also need to be amenable to mass spectrometry imaging, post-translational modification analysis, and multi-omics to facilitate understanding and future treatment of many diseases.
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Affiliation(s)
- Christopher S. Sauer
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Ashley Phetsanthad
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Olga L. Riusech
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53075, USA
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10
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Trimpin S, Marshall DD, Karki S, Madarshahian S, Hoang K, Meher AK, Pophristic M, Richards AL, Lietz CB, Fischer JL, Elia EA, Wang B, Pagnotti VS, Lutomski CA, El-Baba TJ, Lu IC, Wager-Miller J, Mackie K, McEwen CN, Inutan ED. An overview of biological applications and fundamentals of new inlet and vacuum ionization technologies. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35 Suppl 1:e8829. [PMID: 32402102 DOI: 10.1002/rcm.8829] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 05/01/2020] [Accepted: 05/10/2020] [Indexed: 06/11/2023]
Abstract
RATIONALE The developments of new ionization technologies based on processes previously unknown to mass spectrometry (MS) have gained significant momentum. Herein we address the importance of understanding these unique ionization processes, demonstrate the new capabilities currently unmet by other methods, and outline their considerable analytical potential. METHODS The inlet and vacuum ionization methods of solvent-assisted ionization (SAI), matrix-assisted ionization (MAI), and laserspray ionization can be used with commercial and dedicated ion sources producing ions from atmospheric or vacuum conditions for analyses of a variety of materials including drugs, lipids, and proteins introduced from well plates, pipet tips and plate surfaces with and without a laser using solid or solvent matrices. Mass spectrometers from various vendors are employed. RESULTS Results are presented highlighting strengths relative to ionization methods of electrospray ionization (ESI) and matrix-assisted laser desorption/ionization. We demonstrate the utility of multi-ionization platforms encompassing MAI, SAI, and ESI and enabling detection of what otherwise is missed, especially when directly analyzing mixtures. Unmatched robustness is achieved with dedicated vacuum MAI sources with mechanical introduction of the sample to the sub-atmospheric pressure (vacuum MAI). Simplicity and use of a wide array of matrices are attained using a conduit (inlet ionization), preferably heated, with sample introduction from atmospheric pressure. Tissue, whole blood, urine (including mouse, chicken, and human origin), bacteria strains and chemical on-probe reactions are analyzed directly and, especially in the case of vacuum ionization, without concern of carryover or instrument contamination. CONCLUSIONS Examples are provided highlighting the exceptional analytical capabilities associated with the novel ionization processes in MS that reduce operational complexity while increasing speed and robustness, achieving mass spectra with low background for improved sensitivity, suggesting the potential of this simple ionization technology to drive MS into areas currently underserved, such as clinical and medical applications.
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Affiliation(s)
- Sarah Trimpin
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
- MS™, LLC, Newark, DE, 19711, USA
| | - Darrell D Marshall
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
- MS™, LLC, Newark, DE, 19711, USA
| | - Santosh Karki
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
- MS™, LLC, Newark, DE, 19711, USA
| | | | - Khoa Hoang
- MS™, LLC, Newark, DE, 19711, USA
- University of the Sciences, Philadelphia, PA, 19104, USA
| | - Anil K Meher
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
- MS™, LLC, Newark, DE, 19711, USA
| | - Milan Pophristic
- MS™, LLC, Newark, DE, 19711, USA
- University of the Sciences, Philadelphia, PA, 19104, USA
| | - Alicia L Richards
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | | | - Joshua L Fischer
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - Efstathios A Elia
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - Beixi Wang
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | | | - Corinne A Lutomski
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - Tarick J El-Baba
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - I-Chung Lu
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - James Wager-Miller
- Gill Center for Biomolecular Science and Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
| | - Ken Mackie
- Gill Center for Biomolecular Science and Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
| | - Charles N McEwen
- MS™, LLC, Newark, DE, 19711, USA
- University of the Sciences, Philadelphia, PA, 19104, USA
| | - Ellen D Inutan
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
- MS™, LLC, Newark, DE, 19711, USA
- Mindanao State University Iligan Institute of Technology, Iligan City, 9200, Philippines
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11
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Mendel HC, Kaas Q, Muttenthaler M. Neuropeptide signalling systems - An underexplored target for venom drug discovery. Biochem Pharmacol 2020; 181:114129. [PMID: 32619425 PMCID: PMC7116218 DOI: 10.1016/j.bcp.2020.114129] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 01/06/2023]
Abstract
Neuropeptides are signalling molecules mainly secreted from neurons that act as neurotransmitters or peptide hormones to affect physiological processes and modulate behaviours. In humans, neuropeptides are implicated in numerous diseases and understanding their role in physiological processes and pathologies is important for therapeutic development. Teasing apart the (patho)physiology of neuropeptides remains difficult due to ligand and receptor promiscuity and the complexity of the signalling pathways. The current approach relies on a pharmacological toolbox of agonists and antagonists displaying high selectivity for independent receptor subtypes, with the caveat that only few selective ligands have been discovered or developed. Animal venoms represent an underexplored source for novel receptor subtype-selective ligands that could aid in dissecting human neuropeptide signalling systems. Multiple endogenous-like neuropeptides as well as peptides acting on neuropeptide receptors are present in venoms. In this review, we summarise current knowledge on neuropeptides and discuss venoms as a source for ligands targeting neuropeptide signalling systems.
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Affiliation(s)
- Helen C Mendel
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Quentin Kaas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Markus Muttenthaler
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia; University of Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Vienna, Austria.
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12
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Buchberger AR, DeLaney K, Liu Y, Vu NQ, Helfenbein K, Li L. Mass Spectrometric Profiling of Neuropeptides in Callinectes sapidus during Hypoxia Stress. ACS Chem Neurosci 2020; 11:3097-3106. [PMID: 32840999 DOI: 10.1021/acschemneuro.0c00439] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Oxygen (O2) is a critical component of life; without proper O2 levels, cells are unable to respire, meaning glucose cannot be utilized. Thus, hypoxia (low O2 levels) is a well-documented stressor, especially in aquatic environments. Neuropeptides are a major class of regulators for stress-induced responses; however, their global expression changes during stress are not well characterized due to the natural complexity of the nervous system. Beyond being a neurological model organism, crustaceans are regularly exposed to hypoxia, making them a relevant system for this study. Several neuropeptide families, including orcokinins, RFamides, and allatostatin A-types, show dynamic dysregulation due to hypoxic stress. In particular, the brain showed the most dynamic changes with a survival mechanism "switching" (i.e., significant increase to decrease) of neuropeptide content between moderate and severe hypoxia (e.g., NFDEDRSGFA, FDAFTTGFGHS, NRNFLRFamide, and APSGFLGMRamide). Globally, neuropeptides in different tissues appeared to exhibit unique expression patterns at the various severities of hypoxia, including LSSSNSPSSTPL and NFDEIDRSSFGF. Overall, this study provides clear evidence for the benefits of globally analyzing biomolecules and that neuropeptides play a critical role in how crustaceans adapt due to hypoxic stress.
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Affiliation(s)
- Amanda R. Buchberger
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, United States
| | - Kellen DeLaney
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, United States
| | - Yang Liu
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, United States
| | - Nhu Q. Vu
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, United States
| | - Kylie Helfenbein
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, United States
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, United States
- School of Pharmacy, University of Wisconsin-Madison, 5125 Rennebohm Hall, 777 Highland Drive, Madison, Wisconsin 53706, United States
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13
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Huo Y, Liu K, Lou X. Strong additive and synergistic effects of polyoxyethylene nonionic surfactant-assisted protein MALDI imaging mass spectrometry. Talanta 2020; 222:121524. [PMID: 33167234 DOI: 10.1016/j.talanta.2020.121524] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/04/2020] [Accepted: 08/06/2020] [Indexed: 10/23/2022]
Abstract
Protein MALDI imaging mass spectrometry (MALDI-IMS) holds a great promise to acquire spatial distribution information of proteins on biological tissue, but it suffers from the small number of proteins detected by direct MALDI-IMS detection. Ionic surfactants have been extensively used for protein extraction to improve the number of proteins detected in tissue samples by LC-MS analysis, but seldom by direct MALDI-IMS detection. Nonionic surfactants are milder than ionic surfactants and protein native structures are remained after extraction, which favors the spatial resolution of direct MALDI-IMS. However, nonionic surfactants are less effective than ionic surfactants. In this report, we utilized polyoxyethylene nonionic surfactants (PNS) to pre-incubate the tissue section, followed by the on-tissue trypsin digestion and then direct MALDI detection of in-situ formed peptides. For the first time, we observed that the additive effect of PNS and the synergistic effect of the mixed PNS in improving the number of peptides detected. Specifically, the peptides detected were 73.0-90.7% distinct when the different PNS (Tween 80 or Triton X-100 alone or their mixture) was used. Taking advantage of this additive effect, the 96 proteins including 12 transmembrane proteins were detected, corresponding to a ~10-fold improvement compared to MALDI-IMS without surfactant. When the mixed surfactants were used to replace Tween 80 and Triton X-100 alone, the optimized surfactant concentration decreased 20-100-fold and the number of peptides detected with m/z > 2500 Da was improved 15-fold. The additive and synergistic effects of PNS suggested that the interaction mode between each PNS and proteins is highly variable. Benefiting from the strong additive effect and diversity of PNS, further improvement of the number of proteins detected by MALDI-IMS is clearly feasible.
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Affiliation(s)
- Yumeng Huo
- Department of Chemistry, Capital Normal University, Beijing, 100048, China
| | - Kehui Liu
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, 100101, Beijing, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Xinhui Lou
- Department of Chemistry, Capital Normal University, Beijing, 100048, China.
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Buchberger AR, Vu NQ, Johnson J, DeLaney K, Li L. A Simple and Effective Sample Preparation Strategy for MALDI-MS Imaging of Neuropeptide Changes in the Crustacean Brain Due to Hypoxia and Hypercapnia Stress. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:1058-1065. [PMID: 32150406 PMCID: PMC7467133 DOI: 10.1021/jasms.9b00107] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Matrix-assisted laser desorption/ionization (MALDI)-MS imaging has been utilized to image a variety of biomolecules, including neuropeptides. Washing a tissue section is an effective way to eliminate interfering background and improve detection of low concentration target analyte molecules; however, many previous methods have not been tested for neuropeptide analysis via MALDI-MS imaging. Using crustaceans as a neurological model organism, we developed a new, simple washing procedure and applied this method to characterize neuropeptide changes due to hypoxia stress. With a 10 s 50:50 EtOH:H2O wash, neuropeptide coverage was improved by 1.15-fold, while normalized signal intensities were increased by 5.28-fold. Specifically, hypoxia and hypercapnia stress conditions were investigated due to their environmental relevance to marine invertebrates. Many neuropeptides, including RFamides, pyrokinin, and cardioactive peptides, showed distinct up- and down-regulation for specific neuropeptide isoforms. Since crustacean neuropeptides are homologous to those found in humans, results from these studies can be applied to understand potential roles of neuropeptides involved in medical hypoxia and hypercapnia.
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Affiliation(s)
- Amanda R. Buchberger
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706
| | - Nhu Q. Vu
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706
| | - Jillian Johnson
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Ave, Madison, WI 53705
| | - Kellen DeLaney
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Ave, Madison, WI 53705
- Address reprint requests to: Lingjun Li. Mailing Address: 5125 Rennebohm Hall, 777 Highland Avenue, Madison, WI 53706; Phone: (608)265-8491; Fax: (608)262-5345;
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15
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Mast DH, Checco JW, Sweedler JV. Differential Post-Translational Amino Acid Isomerization Found among Neuropeptides in Aplysia californica. ACS Chem Biol 2020; 15:272-281. [PMID: 31877009 DOI: 10.1021/acschembio.9b00910] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
d-Amino acid-containing peptides (DAACPs) make up a class of post-translationally modified peptides in animals that play important roles as cell-to-cell signaling molecules. Despite the functional importance of l- to d-residue isomerization, little is known about its prevalence, mostly due to difficulties associated with detecting differences in peptide stereochemistry. Prior efforts to discover DAACPs have been largely focused on pursuing peptides based on homology to known DAACPs or DAACP-encoding precursors. Here, we used a combination of enzymatic screening, mass spectrometry, and chromatographic analysis to identify novel DAACPs in the central nervous system (CNS) of Aplysia californica. We identified five new DAACPs from the pleurin precursor and three DAACPs from previously uncharacterized proteins. In addition, two peptides from the pleurin precursor, Plrn2 and Plrn3, exist as DAACPs with the d-residue found at position 2 or 3. These differentially modified forms of Plrn2 and Plrn3 are located in specific regions of the animal's CNS. Plrn2 and Plrn3 appear to be the first animal DAACPs in which the d-residue is found at more than one position, and this suggests that l- to d-residue isomerization may be a more variable/dynamic modification than previously thought. Overall, this study demonstrates the utility of nontargeted DAACP discovery approaches for identifying new DAACPs and demonstrates that isomerization is prevalent throughout the CNS of A. californica.
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Affiliation(s)
- David H. Mast
- Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - James W. Checco
- Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Jonathan V. Sweedler
- Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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16
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DeLaney K, Li L. Capillary electrophoresis coupled to MALDI mass spectrometry imaging with large volume sample stacking injection for improved coverage of C. borealis neuropeptidome. Analyst 2019; 145:61-69. [PMID: 31723949 PMCID: PMC6917920 DOI: 10.1039/c9an01883b] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Neuropeptides are important signaling molecules responsible for a wide range of functions within the nervous and neuroendocrine system. However, they are difficult to study due to numerous challenges, most notably their large degree of variability and low abundance in vivo. As a result, effective separation methods with sensitive detection capabilities are necessary for profiling neuropeptides in tissue samples, particularly those of simplified model organisms such as crustaceans. In order to address these challenges, this study utilized a capillary electrophoresis (CE)-matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry imaging (MSI) platform, building upon our previous design for improved neuropeptidomic coverage. The capillary was coated with polyethylenimine (PEI) to reduce peptide adsorption and reverse the electroosmotic flow, and large volume sample stacking (LVSS) was used to load and pre-concentrate 1 μL of sample. The method demonstrated good reproducibility, with lower than 5% relative standard deviation for standards, and a limit of detection of approximately 100 pM for an allatostatin III peptide standard. The method was tested on brain and sinus gland (SG) tissue extracts and enabled detection of over 200 neuropeptides per run. When comparing the number detected in brain extracts in a direct spot, 60-second fractions, and 30-second fractions, the continuous trace collection afforded by the CE-MALDI-MSI platform yielded the largest number of detected neuropeptides. The method was compared to conventional LC-ESI-MS, and though the number of neuropeptides detected by LC-ESI-MS was slightly larger, the two methods were highly complementary, indicating the potential for the CE-MALDI-MSI method to uncover previously undetected neuropeptides in the crustacean nervous system. These results indicate the potential of CE-MALDI-MSI for routine use in neuropeptide research.
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Affiliation(s)
- Kellen DeLaney
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706-1322
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706-1322
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705-2222
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17
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Abstract
Glycosylation is one of the most ubiquitous and complex post-translational modifications (PTMs). It plays pivotal roles in various biological processes. Studies at the glycopeptide level are typically considered as a downstream work resulting from enzymatic digested glycoproteins. Less attention has been focused on glycosylated endogenous signaling peptides due to their low abundance, structural heterogeneity and the lack of enabling analytical tools. Here, protocols are presented to isolate and characterize glycosylated neuropeptides utilizing nanoflow liquid chromatography coupled with mass spectrometry (LC-MS). We first demonstrate how to extract neuropeptides from raw tissues and perform further separation/cleanup before MS analysis. Then we describe hybrid MS methods for glycosylated neuropeptide profiling and site-specific analysis. We also include recommendations for data analysis to identify glycosylated neuropeptides in crustaceans where a complete neuropeptide database is still lacking. Other strategies and future directions are discussed to provide readers with alternative approaches and further unravel biological complexity rendered by glycosylation.
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Affiliation(s)
- Yang Liu
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, United States
| | - Qinjingwen Cao
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, United States
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, United States; School of Pharmacy, University of Wisconsin-Madison, Madison, WI, United States.
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18
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Trimpin S. Novel ionization processes for use in mass spectrometry: 'Squeezing' nonvolatile analyte ions from crystals and droplets. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33 Suppl 3:96-120. [PMID: 30138957 DOI: 10.1002/rcm.8269] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/29/2018] [Accepted: 08/15/2018] [Indexed: 05/25/2023]
Abstract
Together with my group and collaborators, I have been fortunate to have had a key role in the discovery of new ionization processes that we developed into new flexible, sensitive, rapid, reliable, and robust ionization technologies and methods for use in mass spectrometry (MS). Our current research is focused on how best to understand, improve, and use these novel ionization processes which convert volatile and nonvolatile compounds from solids or liquids into gas-phase ions for analysis by MS using e.g. mass-selected fragmentation and ion mobility spectrometry to provide reproducible, accurate, and improved mass and drift time resolution. In my view, the apex was the discovery of vacuum matrix-assisted ionization (vMAI) in 2012 on an intermediate pressure matrix-assisted laser desorption/ionization (MALDI) source without the use of a laser, high voltages, or any other added energy. Only exposure of the matrix:analyte to the sub-atmospheric pressure of the mass spectrometer was necessary to initiate ionization. These findings were initially rejected by three different scientific journals, with comments related to 'how can this work?', 'where do the charges come from?', and 'it is not analytically useful'. Meanwhile, we and others have demonstrated analytical utility without a complete understanding of the mechanism. In reality, MALDI and electrospray ionization are widely used in science and their mechanisms are still controversially discussed despite use and optimization of now 30 years. This Perspective covers the applications and mechanistic aspects of the novel ionization processes for use in MS that guided us in instrument developments, and provides our perspective on how they relate to traditional ionization processes.
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Affiliation(s)
- Sarah Trimpin
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
- Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI, 48201, USA
- MSTM, LLC, Newark, DE, 19711, USA
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19
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Hanley L, Wickramasinghe R, Yung YP. Laser Desorption Combined with Laser Postionization for Mass Spectrometry. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2019; 12:225-245. [PMID: 30786215 DOI: 10.1146/annurev-anchem-061318-115447] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Lasers with pulse lengths from nanoseconds to femtoseconds and wavelengths from the mid-infrared to extreme ultraviolet (UV) have been used for desorption or ablation in mass spectrometry. Such laser sampling can often benefit from the addition of a second laser for postionization of neutrals. The advantages offered by laser postionization include the ability to forego matrix application, high lateral resolution, decoupling of ionization from desorption, improved analysis of electrically insulating samples, and potential for high sensitivity and depth profiling while minimizing differential detection. A description of postionization by vacuum UV radiation is followed by a consideration of multiphoton, short pulse, and other postionization strategies. The impacts of laser pulse length and wavelength are considered for laser desorption or laser ablation at low pressures. Atomic and molecular analysis via direct laser desorption/ionization using near-infrared ultrashort pulses is described. Finally, the postionization of clusters, the role of gaseous collisions, sampling at ambient pressure, atmospheric pressure photoionization, and the addition of UV postionization to MALDI are considered.
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Affiliation(s)
- Luke Hanley
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, USA;
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20
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Hook V, Kind T, Podvin S, Palazoglu M, Tran C, Toneff T, Samra S, Lietz C, Fiehn O. Metabolomics Analyses of 14 Classical Neurotransmitters by GC-TOF with LC-MS Illustrates Secretion of 9 Cell-Cell Signaling Molecules from Sympathoadrenal Chromaffin Cells in the Presence of Lithium. ACS Chem Neurosci 2019; 10:1369-1379. [PMID: 30698015 DOI: 10.1021/acschemneuro.8b00432] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The classical small molecule neurotransmitters are essential for cell-cell signaling in the nervous system for regulation of behaviors and physiological functions. Metabolomics approaches are ideal for quantitative analyses of neurotransmitter profiles but have not yet been achieved for the repertoire of 14 classical neurotransmitters. Therefore, this study developed targeted metabolomics analyses by full scan gas chromatography/time-of-flight mass spectrometry (GC-TOF) and hydrophilic interaction chromatography-QTRAP mass spectrometry (HILIC-MS/MS) operated in positive ionization mode for identification and quantitation of 14 neurotransmitters consisting of acetylcholine, adenosine, anandamide, aspartate, dopamine, epinephrine, GABA, glutamate, glycine, histamine, melatonin, norepinephrine, serine, and serotonin. GC-TOF represents a new metabolomics method for neurotransmitter analyses. Sensitive measurements of 11 neurotransmitters were achieved by GC-TOF, and three neurotransmitters were analyzed by LC-MS/MS (acetylcholine, anandamide, and melatonin). The limits of detection (LOD) and limits of quantitation (LOQ) were assessed for linearity for GC-TOF and LC-MS/MS protocols. In neurotransmitter-containing dense core secretory vesicles of adrenal medulla, known as chromaffin granules (CG), metabolomics measured the concentrations of 9 neurotransmitters consisting of the catecholamines dopamine, norepinephrine, and epinephrine, combined with glutamate, serotonin, adenosine, aspartate, glycine, and serine. The CG neurotransmitters were constitutively secreted from sympathoadrenal chromaffin cells in culture. Nicotine- and KCl-stimulated release of the catecholamines and adenosine. Lithium, a drug used for the treatment of bipolar disorder, decreased the constitutive secretion of dopamine and norepinephrine and decreased nicotine-stimulated secretion of epinephrine. Lithium had no effect on other secreted neurotransmitters. Overall, the newly developed GC-TOF with LC-MS/MS metabolomics methods for analyses of 14 neurotransmitters will benefit investigations of neurotransmitter regulation in biological systems and in human disease conditions related to drug treatments.
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Affiliation(s)
- Vivian Hook
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
- Department of Neurosciences and Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Tobias Kind
- West Coast Metabolomics Center, UC Davis Genome Center, University of California, Davis, Davis, California 95616, United States
| | - Sonia Podvin
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Mine Palazoglu
- West Coast Metabolomics Center, UC Davis Genome Center, University of California, Davis, Davis, California 95616, United States
| | - Carol Tran
- West Coast Metabolomics Center, UC Davis Genome Center, University of California, Davis, Davis, California 95616, United States
| | - Thomas Toneff
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Stephanie Samra
- West Coast Metabolomics Center, UC Davis Genome Center, University of California, Davis, Davis, California 95616, United States
| | - Christopher Lietz
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Oliver Fiehn
- West Coast Metabolomics Center, UC Davis Genome Center, University of California, Davis, Davis, California 95616, United States
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21
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Yang N, Anapindi KDB, Romanova EV, Rubakhin SS, Sweedler JV. Improved identification and quantitation of mature endogenous peptides in the rodent hypothalamus using a rapid conductive sample heating system. Analyst 2018; 142:4476-4485. [PMID: 29098220 DOI: 10.1039/c7an01358b] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Measurement, identification, and quantitation of endogenous peptides in tissue samples by mass spectrometry (MS) contribute to our understanding of the complex molecular mechanisms of numerous biological phenomena. For accurate results, it is essential to arrest the postmortem degradation of ubiquitous proteins in samples prior to performing peptidomic measurements. Doing so ensures that the detection of endogenous peptides, typically present at relatively low levels of abundance, is not overwhelmed by protein degradation products. Heat stabilization has been shown to inactivate the enzymes in tissue samples and minimize the presence of protein degradation products in the subsequent peptide extracts. However, the efficacy of different heat treatments to preserve the integrity of full-length endogenous peptides has not been well documented; prior peptidomic studies of heat stabilization methods have not distinguished between the full-length (mature) and numerous truncated (possible artifacts of sampling) forms of endogenous peptides. We show that thermal sample treatment via rapid conductive heat transfer is effective for detection of mature endogenous peptides in fresh and frozen rodent brain tissues. Freshly isolated tissue processing with the commercial Stabilizor T1 heat stabilization system resulted in the confident identification of 65% more full-length mature neuropeptides compared to widely used sample treatment in a hot water bath. This finding was validated by a follow-up quantitative multiple reaction monitoring MS analysis of select neuropeptides. The rapid conductive heating in partial vacuum provided by the Stabilizor T1 effectively reduces protein degradation and decreases the chemical complexity of the sample, as assessed by determining total protein content. This system enabled the detection, identification, and quantitation of neuropeptides related to 22 prohormones expressed in individual rat hypothalami and suprachiasmatic nuclei.
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Affiliation(s)
- Ning Yang
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana 61801, USA.
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22
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Zhang G, Yuan WD, Vilim FS, Romanova EV, Yu K, Yin SY, Le ZW, Xue YY, Chen TT, Chen GK, Chen SA, Cropper EC, Sweedler JV, Weiss KR, Jing J. Newly Identified Aplysia SPTR-Gene Family-Derived Peptides: Localization and Function. ACS Chem Neurosci 2018. [PMID: 29543430 DOI: 10.1021/acschemneuro.7b00513] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
When individual neurons in a circuit contain multiple neuropeptides, these peptides can target different sets of follower neurons. This endows the circuit with a certain degree of flexibility. Here we identified a novel family of peptides, the Aplysia SPTR-Gene Family-Derived peptides (apSPTR-GF-DPs). We demonstrated apSPTR-GF-DPs, particularly apSPTR-GF-DP2, are expressed in the Aplysia CNS using immunohistochemistry and MALDI-TOF MS. Furthermore, apSPTR-GF-DP2 is present in single projection neurons, e.g., in the cerebral-buccal interneuron-12 (CBI-12). Previous studies have demonstrated that CBI-12 contains two other peptides, FCAP/CP2. In addition, CBI-12 and CP2 promote shortening of the protraction phase of motor programs. Here, we demonstrate that FCAP shortens protraction. Moreover, we show that apSPTR-GF-DP2 also shortens protraction. Surprisingly, apSPTR-GF-DP2 does not increase the excitability of retraction interneuron B64. B64 terminates protraction and is modulated by FCAP/CP2 and CBI-12. Instead, we show that apSPTR-GF-DP2 and CBI-12 increase B20 excitability and B20 activity can shorten protraction. Taken together, these data indicate that different CBI-12 peptides target different sets of pattern-generating interneurons to exert similar modulatory actions. These findings provide the first definitive evidence for SPTR-GF's role in modulation of feeding, and a form of molecular degeneracy by multiple peptide cotransmitters in single identified neurons.
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Affiliation(s)
- Guo Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210046, China
| | - Wang-ding Yuan
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210046, China
| | - Ferdinand S. Vilim
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Elena V. Romanova
- Beckman Institute for Advanced Science and Technology and Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Ke Yu
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210046, China
| | - Si-yuan Yin
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210046, China
| | - Zi-wei Le
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210046, China
| | - Ying-yu Xue
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210046, China
| | - Ting-ting Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210046, China
| | - Guo-kai Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210046, China
| | - Song-an Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210046, China
| | - Elizabeth C. Cropper
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Jonathan V. Sweedler
- Beckman Institute for Advanced Science and Technology and Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Klaudiusz R. Weiss
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Jian Jing
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210046, China
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
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23
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Jiang X, Xiang F, Jia C, Buchberger AR, Li L. Relative Quantitation of Neuropeptides at Multiple Developmental Stages of the American Lobster Using N, N-Dimethyl Leucine Isobaric Tandem Mass Tags. ACS Chem Neurosci 2018; 9:2054-2063. [PMID: 29357224 DOI: 10.1021/acschemneuro.7b00521] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Neuromodulators and neurotransmitters play important roles in neural network development. The quantitative changes of these signaling molecules often reflect their regulatory roles in physiological processes. Currently, several commercial tags (e.g., iTRAQ and TMT) have been widely used in proteomics. With reduced cost and higher labeling efficiency, we employed a set of custom-developed N, N-dimethyl leucine (DiLeu) 4-plex isobaric tandem mass tags as an attractive alternative for the relative quantitation of neuropeptides in brain tissue of American lobster Homarus americanus at multiple developmental stages. A general workflow for isobaric labeling of neuropeptides followed by LC-MS/MS analysis has been developed, including optimized sample handling procedures. Overall, we were able to quantify 18 trace-amount neuropeptides from 6 different families using a single adult brain as a control. The quantitation results indicated that the expressions of different neuropeptide families had significant changes over distinct developmental stages. Additionally, our data revealed intriguing elevated expression of neuropeptides in the early juvenile development stage. The methodology presented here advanced the workflow of DiLeu as an alternative labeling approach and the application of DiLeu-based quantitative peptidomics, which can be extended to areas beyond neuroscience.
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Affiliation(s)
- Xiaoyue Jiang
- School of Pharmacy, University of Wisconsin—Madison, 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Feng Xiang
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Chenxi Jia
- School of Pharmacy, University of Wisconsin—Madison, 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Amanda Rae Buchberger
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Lingjun Li
- School of Pharmacy, University of Wisconsin—Madison, 777 Highland Avenue, Madison, Wisconsin 53705, United States
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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24
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Hook V, Lietz CB, Podvin S, Cajka T, Fiehn O. Diversity of Neuropeptide Cell-Cell Signaling Molecules Generated by Proteolytic Processing Revealed by Neuropeptidomics Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:807-816. [PMID: 29667161 PMCID: PMC5946320 DOI: 10.1007/s13361-018-1914-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 02/07/2018] [Accepted: 02/08/2018] [Indexed: 05/23/2023]
Abstract
Neuropeptides are short peptides in the range of 3-40 residues that are secreted for cell-cell communication in neuroendocrine systems. In the nervous system, neuropeptides comprise the largest group of neurotransmitters. In the endocrine system, neuropeptides function as peptide hormones to coordinate intercellular signaling among target physiological systems. The diversity of neuropeptide functions is defined by their distinct primary sequences, peptide lengths, proteolytic processing of pro-neuropeptide precursors, and covalent modifications. Global, untargeted neuropeptidomics mass spectrometry is advantageous for defining the structural features of the thousands to tens of thousands of neuropeptides present in biological systems. Defining neuropeptide structures is the basis for defining the proteolytic processing pathways that convert pro-neuropeptides into active peptides. Neuropeptidomics has revealed that processing of pro-neuropeptides occurs at paired basic residues sites, and at non-basic residue sites. Processing results in neuropeptides with known functions and generates novel peptides representing intervening peptide domains flanked by dibasic residue processing sites, identified by neuropeptidomics. While very short peptide products of 2-4 residues are predicted from pro-neuropeptide dibasic processing sites, such peptides have not been readily identified; therefore, it will be logical to utilize metabolomics to identify very short peptides with neuropeptidomics in future studies. Proteolytic processing is accompanied by covalent post-translational modifications (PTMs) of neuropeptides comprising C-terminal amidation, N-terminal pyroglutamate, disulfide bonds, phosphorylation, sulfation, acetylation, glycosylation, and others. Neuropeptidomics can define PTM features of neuropeptides. In summary, neuropeptidomics for untargeted, global analyses of neuropeptides is essential for elucidation of proteases that generate diverse neuropeptides for cell-cell signaling. Graphical Abstract ᅟ.
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Affiliation(s)
- Vivian Hook
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Dr. MC0719, La Jolla, CA, 92093-0719, USA.
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA.
| | - Christopher B Lietz
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Dr. MC0719, La Jolla, CA, 92093-0719, USA
| | - Sonia Podvin
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Dr. MC0719, La Jolla, CA, 92093-0719, USA
| | - Tomas Cajka
- West Coast Metabolomics Center, UC Davis Genome Center, University of California Davis, Davis, CA, 95616, USA
| | - Oliver Fiehn
- West Coast Metabolomics Center, UC Davis Genome Center, University of California Davis, Davis, CA, 95616, USA
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25
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Wilson RE, Jaquins-Gerstl A, Weber SG. On-Column Dimethylation with Capillary Liquid Chromatography-Tandem Mass Spectrometry for Online Determination of Neuropeptides in Rat Brain Microdialysate. Anal Chem 2018; 90:4561-4568. [PMID: 29504751 PMCID: PMC6236683 DOI: 10.1021/acs.analchem.7b04965] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
We have developed a method for online collection and quantitation of neuropeptides in rat brain microdialysates using on-column dimethylation with capillary liquid chromatography-tandem mass spectrometry (cLC-MS2). This method addresses a number of the challenges of quantifying neuropeptides with cLC-MS. It is also a completely automated and robust method for the preparation of stable isotope labeled-peptide internal standards to correct for matrix effects and thus ensure accurate quantitation. Originally developed for tissue-derived proteomics samples ( Raijmakers et al. Mol. Cell. Proteomics 2008 , 7 , 1755 - 1762 ), the efficacy of on-column dimethylation for native peptides in microdialysate has not been demonstrated until now. We have modified the process to make it more amenable to the time scale of microdialysis sampling and to reduce the accumulation of nonvolatile contaminants on the column and, thus, loss of sensitivity. By decreasing labeling time, we have a temporal resolution of 1 h from sample loading to elution and our peptide detection limits are in the low pM range for 5 μL injections of microdialysate. We have demonstrated the effectiveness of this method by quantifying basal and potassium stimulated concentrations of the neuropeptides leu-enkephalin and met-enkephalin in the rat hippocampus. To our knowledge, this is the first report of quantitation of these peptides in the hippocampus using MS.
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Affiliation(s)
- Rachael E Wilson
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Andrea Jaquins-Gerstl
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Stephen G Weber
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
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26
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Yang N, Anapindi KDB, Rubakhin SS, Wei P, Yu Q, Li L, Kenny PJ, Sweedler JV. Neuropeptidomics of the Rat Habenular Nuclei. J Proteome Res 2018. [PMID: 29518334 DOI: 10.1021/acs.jproteome.7b00811] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Conserved across vertebrates, the habenular nuclei are a pair of small symmetrical structures in the epithalamus. The nuclei functionally link the forebrain and midbrain by receiving input from and projecting to several brain regions. Each habenular nucleus comprises two major asymmetrical subnuclei, the medial and lateral habenula. These subnuclei are associated with different physiological processes and disorders, such as depression, nicotine addiction, and encoding aversive stimuli or omitting expected rewarding stimuli. Elucidating the functions of the habenular nuclei at the molecular level requires knowledge of their neuropeptide complement. In this work, three mass spectrometry (MS) techniques-liquid chromatography (LC) coupled to Orbitrap tandem MS (MS/MS), LC coupled to Fourier transform (FT)-ion cyclotron resonance (ICR) MS/MS, and matrix-assisted laser desorption/ionization (MALDI) FT-ICR MS-were used to uncover the neuropeptide profiles of the rodent medial and lateral habenula. With the assistance of tissue stabilization and bioinformatics, a total of 262 and 177 neuropeptides produced from 27 and 20 prohormones were detected and identified from the medial and lateral habenula regions, respectively. Among these neuropeptides, 136 were exclusively found in the medial habenula, and 51 were exclusively expressed in the lateral habenula. Additionally, novel sites of sulfation, a rare post-translational modification, on the secretogranin I prohormone are identified. The results demonstrate that these two small brain nuclei have a rich and differentiated peptide repertoire, with this information enabling a range of follow-up studies.
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Affiliation(s)
- Ning Yang
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Krishna D B Anapindi
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Stanislav S Rubakhin
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Pingli Wei
- Chemistry Department , University of Wisconsin-Madison , Madison , Wisconsin 53705 , United States
| | - Qing Yu
- School of Pharmacy , University of Wisconsin-Madison , Madison , Wisconsin 53705 , United States
| | - Lingjun Li
- Chemistry Department , University of Wisconsin-Madison , Madison , Wisconsin 53705 , United States.,School of Pharmacy , University of Wisconsin-Madison , Madison , Wisconsin 53705 , United States
| | - Paul J Kenny
- Department of Pharmacology & Systems Therapeutics , Icahn School of Medicine at Mount Sinai , New York , New York 10029 , United States
| | - Jonathan V Sweedler
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
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27
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DeLaney K, Buchberger AR, Atkinson L, Gründer S, Mousley A, Li L. New techniques, applications and perspectives in neuropeptide research. ACTA ACUST UNITED AC 2018; 221:221/3/jeb151167. [PMID: 29439063 DOI: 10.1242/jeb.151167] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Neuropeptides are one of the most diverse classes of signaling molecules and have attracted great interest over the years owing to their roles in regulation of a wide range of physiological processes. However, there are unique challenges associated with neuropeptide studies stemming from the highly variable molecular sizes of the peptides, low in vivo concentrations, high degree of structural diversity and large number of isoforms. As a result, much effort has been focused on developing new techniques for studying neuropeptides, as well as novel applications directed towards learning more about these endogenous peptides. The areas of importance for neuropeptide studies include structure, localization within tissues, interaction with their receptors, including ion channels, and physiological function. Here, we discuss these aspects and the associated techniques, focusing on technologies that have demonstrated potential in advancing the field in recent years. Most identification and structural information has been gained by mass spectrometry, either alone or with confirmations from other techniques, such as nuclear magnetic resonance spectroscopy and other spectroscopic tools. While mass spectrometry and bioinformatic tools have proven to be the most powerful for large-scale analyses, they still rely heavily on complementary methods for confirmation. Localization within tissues, for example, can be probed by mass spectrometry imaging, immunohistochemistry and radioimmunoassays. Functional information has been gained primarily from behavioral studies coupled with tissue-specific assays, electrophysiology, mass spectrometry and optogenetic tools. Concerning the receptors for neuropeptides, the discovery of ion channels that are directly gated by neuropeptides opens up the possibility of developing a new generation of tools for neuroscience, which could be used to monitor neuropeptide release or to specifically change the membrane potential of neurons. It is expected that future neuropeptide research will involve the integration of complementary bioanalytical technologies and functional assays.
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Affiliation(s)
- Kellen DeLaney
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Amanda R Buchberger
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Louise Atkinson
- School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Stefan Gründer
- Institute of Physiology, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany
| | - Angela Mousley
- School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA .,School of Pharmacy, University of Wisconsin-Madison, 1450 Linden Drive, Madison, WI 53706, USA
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28
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Rae Buchberger A, DeLaney K, Johnson J, Li L. Mass Spectrometry Imaging: A Review of Emerging Advancements and Future Insights. Anal Chem 2018; 90:240-265. [PMID: 29155564 PMCID: PMC5959842 DOI: 10.1021/acs.analchem.7b04733] [Citation(s) in RCA: 552] [Impact Index Per Article: 92.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Amanda Rae Buchberger
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Kellen DeLaney
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Jillian Johnson
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705, United States
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29
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Rapid Identification of Dipeptidyl Peptidase-IV (DPP-IV) Inhibitory Peptides from Ruditapes philippinarum Hydrolysate. Molecules 2017; 22:molecules22101714. [PMID: 29027968 PMCID: PMC6151561 DOI: 10.3390/molecules22101714] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/08/2017] [Accepted: 10/09/2017] [Indexed: 01/08/2023] Open
Abstract
Dipeptidyl peptidase-IV (DPP-IV) inhibitory peptides were rapidly identified from Ruditapes philippinarum hydrolysate. The hydrolysate was fractionated by ethanol precipitation and preparative reverse phase high-performance liquid chromatography (RP-HPLC). The fraction which showed the highest DPP-IV inhibitory activity was then analyzed by a high-throughput nano-liquid chromatography electrospray ionization tandem mass spectrometry (nano-LC ESI-MS/MS) method, and the sequences of peptides were identified based on the MS/MS spectra against the Mollusca protein data from the UniProt database. In total, 50 peptides were identified. Furthermore, molecular docking was used to identify potential DPP-IV inhibitors from the identified peptides. Docking results suggested that four peptides: FAGDDAPR, LAPSTM, FAGDDAPRA, and FLMESH, could bind pockets of DPP-IV through hydrogen bonds, π-π bonds, and charge interactions. The four peptides were chemically synthesized and tested for DPP-IV inhibitory activity. The results showed that they possessed DPP-IV inhibitory activity with IC50 values of 168.72 μM, 140.82 μM, 393.30 μM, and >500 μM, respectively. These results indicate that R. philippinarum-derived peptides may have potential as functional food ingredients for the prevention of diabetes.
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30
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Greening DW, Kapp EA, Simpson RJ. The Peptidome Comes of Age: Mass Spectrometry-Based Characterization of the Circulating Cancer Peptidome. Enzymes 2017; 42:27-64. [PMID: 29054270 DOI: 10.1016/bs.enz.2017.08.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Peptides play a seminal role in most physiological processes acting as neurotransmitters, hormones, antibiotics, and immune regulation. In the context of tumor biology, it is hypothesized that endogenous peptides, hormones, cytokines, growth factors, and aberrant degradation of select protein networks (e.g., enzymatic activities, protein shedding, and extracellular matrix remodeling) are fundamental in mediating cancer progression. Analysis of peptides in biological fluids by mass spectrometry holds promise of providing sensitive and specific diagnostic and prognostic information for cancer and other diseases. The identification of circulating peptides in the context of disease constitutes a hitherto source of new clinical biomarkers. The field of peptidomics can be defined as the identification and comprehensive analysis of physiological and pathological peptides. Like proteomics, peptidomics has been advanced by the development of new separation strategies, analytical detection methods such as mass spectrometry, and bioinformatic technologies. Unlike proteomics, peptidomics is targeted toward identifying endogenous protein and peptide fragments, defining proteolytic enzyme substrate specificity, as well as protease cleavage recognition (degradome). Peptidomics employs "top-down proteomics" strategies where mass spectrometry is applied at the proteoform level to analyze intact proteins and large endogenous peptide fragments. With recent advances in prefractionation workflows for separating peptides, mass spectrometry instrumentation, and informatics, peptidomics is an important field that promises to impact on translational medicine. This review covers the current advances in peptidomics, including top-down and imaging mass spectrometry, comprehensive quantitative peptidome analyses (developments in reproducibility and coverage), peptide prefractionation and enrichment workflows, peptidomic data analyses, and informatic tools. The application of peptidomics in cancer biomarker discovery will be discussed.
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Affiliation(s)
- David W Greening
- La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria, Australia.
| | - Eugene A Kapp
- Systems Biology & Personalised Medicine Division, Walter & Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Florey Institute of Neuroscience, Parkville, Victoria, Australia; University of Melbourne, Parkville, Victoria, Australia
| | - Richard J Simpson
- La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria, Australia.
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31
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Yu Q, Canales A, Glover MS, Das R, Shi X, Liu Y, Keller MP, Attie AD, Li L. Targeted Mass Spectrometry Approach Enabled Discovery of O-Glycosylated Insulin and Related Signaling Peptides in Mouse and Human Pancreatic Islets. Anal Chem 2017; 89:9184-9191. [PMID: 28726377 PMCID: PMC6314835 DOI: 10.1021/acs.analchem.7b01926] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
O-Linked glycosylation often involves the covalent attachment of sugar moieties to the hydroxyl group of serine or threonine on proteins/peptides. Despite growing interest in glycoproteins, little attention has been directed to glycosylated signaling peptides, largely due to lack of enabling analytical tools. Here we explore the occurrence of naturally O-linked glycosylation on the signaling peptides extracted from mouse and human pancreatic islets using mass spectrometry (MS). A novel targeted MS-based method is developed to increase the likelihood of capturing these modified signaling peptides and to provide improved sequence coverage and accurate glycosite localization, enabling the first large-scale discovery of O-glycosylation on signaling peptides. Several glycosylated signaling peptides with multiple glycoforms are identified, including the first report of glycosylated insulin-B chain and insulin-C peptide and BigLEN. This discovery may reveal potential novel functions as glycosylation could influence their conformation and biostability. Given the importance of insulin and its related peptide hormones and previous studies of glycosylated insulin analogues, this natural glycosylation may provide important insights into diabetes research and therapeutic treatments.
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Affiliation(s)
- Qing Yu
- School of Pharmacy, University of Wisconsin, Madison, Wisconsin 53705, United States
| | - Alejandra Canales
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Matthew S. Glover
- School of Pharmacy, University of Wisconsin, Madison, Wisconsin 53705, United States
| | - Rahul Das
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Xudong Shi
- Department of Surgery, Wisconsin Institute for Medical Research, Madison, Wisconsin 53705, United States
| | - Yang Liu
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Mark P. Keller
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Alan D. Attie
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Lingjun Li
- School of Pharmacy, University of Wisconsin, Madison, Wisconsin 53705, United States
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
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32
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Ye H, Wang J, Tian Z, Ma F, Dowell J, Bremer Q, Lu G, Baldo B, Li L. Quantitative Mass Spectrometry Reveals Food Intake-Induced Neuropeptide Level Changes in Rat Brain: Functional Assessment of Selected Neuropeptides as Feeding Regulators. Mol Cell Proteomics 2017; 16:1922-1937. [PMID: 28864778 DOI: 10.1074/mcp.ra117.000057] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Indexed: 12/27/2022] Open
Abstract
Endogenous neuropeptides are important signaling molecules that function as regulators of food intake and body weight. Previous work has shown that neuropeptide gene expression levels in a forebrain reward site, the nucleus accumbens (NAc), were changed by feeding. To directly monitor feeding-induced changes in neuropeptide expression levels within the NAc, we employed a combination of cryostat dissection, heat stabilization, neuropeptide extraction and label-free quantitative neuropeptidomics via a liquid chromatography-high resolution mass spectrometry platform. Using this methodology, we described the first neuropeptidome in NAc and discovered that feeding caused the expression level changes of multiple neuropeptides derived from different precursors, especially proSAAS-derived peptides such as Big LEN, PEN and little SAAS. We further investigated the regulatory functions of these neuropeptides derived from the ProSAAS family by performing an intra-NAc microinjection experiment using the identified ProSAAS neuropeptides, 'Big-LEN' and 'PEN'. Big LEN significantly increased rats' food and water intake, whereas both big LEN and PEN affected other behaviors including locomotion, drinking and grooming. In addition, we quantified the feeding-induced changes of peptides from hippocampus, hypothalamus and striatum to reveal the neuropeptide interplay among different anatomical regions. In summary, our study demonstrated neuropeptidomic changes in response to food intake in the rat NAc and other key brain regions. Importantly, the microinfusion of ProSAAS peptides into NAc revealed that they are behaviorally active in this brain site, suggesting the potential use of these peptides as therapeutics for eating disorders.
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Affiliation(s)
- Hui Ye
- From the ‡State Key Laboratory of Natural Medicines, Key Lab of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Tongjiaxiang #24, Nanjing 21009, China.,§School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705
| | - Jingxin Wang
- ¶Neuroscience Training Program, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705
| | - Zichuan Tian
- ‖Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706
| | - Fengfei Ma
- §School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705
| | - James Dowell
- §School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705
| | - Quentin Bremer
- **Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Boulevard, Madison, Wisconsin 53719
| | - Gaoyuan Lu
- From the ‡State Key Laboratory of Natural Medicines, Key Lab of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Tongjiaxiang #24, Nanjing 21009, China
| | - Brian Baldo
- ¶Neuroscience Training Program, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705; .,**Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Boulevard, Madison, Wisconsin 53719
| | - Lingjun Li
- §School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53705; .,¶Neuroscience Training Program, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705.,‖Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706.,‡‡School of Life Sciences, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin 300072, China
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33
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Choi SB, Zamarbide M, Manzini MC, Nemes P. Tapered-Tip Capillary Electrophoresis Nano-Electrospray Ionization Mass Spectrometry for Ultrasensitive Proteomics: the Mouse Cortex. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:597-607. [PMID: 27853976 DOI: 10.1007/s13361-016-1532-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 10/16/2016] [Accepted: 10/18/2016] [Indexed: 06/06/2023]
Abstract
Ultrasensitive characterization of the proteome raises the potential to understand how differential gene expression orchestrates cell heterogeneity in the brain. Here, we report a microanalytical capillary electrophoresis nano-flow electrospray ionization (CE-nanoESI) interface for mass spectrometry to enable the measurement of limited amounts of proteins in the mouse cortex. Our design integrates a custom-built CE system to a tapered-tip metal emitter in a co-axial sheath-flow configuration. This interface can be constructed in <15 min using readily available components, facilitating broad adaptation. Tapered-tip CE-nanoESI generates stable electrospray by reproducibly anchoring the Taylor cone, minimizes sample dilution in the ion source, and ensures efficient ion generation by sustaining the cone-jet spraying regime. Parallel reaction monitoring provided a 260-zmol lower limit of detection for angiotensin II (156,000 copies). CE was able to resolve a complex mixture of peptides in ~330,000 theoretical plates and identify ~15 amol (~1 pg) of BSA or cytochrome c. Over 30 min of separation, 1 ng protein digest from the mouse cortex yielded 217 nonredundant proteins encompassing a ~3-log-order concentration range using a quadrupole time-of-flight mass spectrometer. Identified proteins included many products from genes that are traditionally used to mark oligodendrocytes, astrocytes, and microglia. Finally, key proteins involved in neurodegenerative disorders were detected (e.g., parkinsonism and spastic paraplegia). CE-nanoESI-HRMS delivers sufficient sensitivity to detect proteins in limited amounts of tissues and cell populations to help understand how gene expression differences maintain cell heterogeneity in the brain. Graphical Abstract ᅟ.
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Affiliation(s)
- Sam B Choi
- Department of Chemistry, The George Washington University, Washington, DC, 20052, USA
| | - Marta Zamarbide
- Department of Pharmacology and Physiology, The George Washington University, Washington, DC, 20037, USA
| | - M Chiara Manzini
- Department of Pharmacology and Physiology, The George Washington University, Washington, DC, 20037, USA
| | - Peter Nemes
- Department of Chemistry, The George Washington University, Washington, DC, 20052, USA.
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34
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Dennis EA, Gundlach-Graham AW, Ray SJ, Enke CG, Hieftje GM. Distance-of-Flight Mass Spectrometry: What, Why, and How? JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:1772-1786. [PMID: 27562501 DOI: 10.1007/s13361-016-1458-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 07/15/2016] [Accepted: 07/19/2016] [Indexed: 06/06/2023]
Abstract
Distance-of-flight mass spectrometry (DOFMS) separates ions of different mass-to-charge (m/z) by the distance they travel in a given time after acceleration. Like time-of-flight mass spectrometry (TOFMS), separation and mass assignment are based on ion velocity. However, DOFMS is not a variant of TOFMS; different methods of ion focusing and detection are used. In DOFMS, ions are driven orthogonally, at the detection time, onto an array of detectors parallel to the flight path. Through the independent detection of each m/z, DOFMS can provide both wider dynamic range and increased throughput for m/z of interest compared with conventional TOFMS. The iso-mass focusing and detection of ions is achieved by constant-momentum acceleration (CMA) and a linear-field ion mirror. Improved energy focus (including turn-around) is achieved in DOFMS, but the initial spatial dispersion of ions remains unchanged upon detection. Therefore, the point-source nature of surface ionization techniques could put them at an advantage for DOFMS. To date, three types of position-sensitive detectors have been used for DOFMS: a microchannel plate with a phosphorescent screen, a focal plane camera, and an IonCCD array; advances in detector technology will likely improve DOFMS figures-of-merit. In addition, the combination of CMA with TOF detection has provided improved resolution and duty factor over a narrow m/z range (compared with conventional, single-pass TOFMS). The unique characteristics of DOFMS can enable the intact collection of large biomolecules, clusters, and organisms. DOFMS might also play a key role in achieving the long-sought goal of simultaneous MS/MS. Graphical Abstract ᅟ.
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Affiliation(s)
- Elise A Dennis
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
- Perkin Elmer, Shelton, CT, 06484, USA
| | - Alexander W Gundlach-Graham
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
- Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland
| | - Steven J Ray
- Department of Chemistry, State University of New York at Buffalo, Buffalo, NY, 14260, USA
| | - Christie G Enke
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Gary M Hieftje
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA.
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35
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Gemperline E, Keller C, Jayaraman D, Maeda J, Sussman MR, Ané JM, Li L. Examination of Endogenous Peptides in Medicago truncatula Using Mass Spectrometry Imaging. J Proteome Res 2016; 15:4403-4411. [PMID: 27726374 DOI: 10.1021/acs.jproteome.6b00471] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Plant science is an important, rapidly developing area of study. Within plant science, one area of study that has grown tremendously with recent technological advances, such as mass spectrometry, is the field of plant-omics; however, plant peptidomics is relatively underdeveloped in comparison with proteomics and metabolomics. Endogenous plant peptides can act as signaling molecules and have been shown to affect cell division, development, nodulation, reproduction, symbiotic associations, and defense reactions. There is a growing need to uncover the role of endogenous peptides on a molecular level. Mass spectrometric imaging (MSI) is a valuable tool for biological analyses as it allows for the detection of thousands of analytes in a single experiment and also displays spatial information for the detected analytes. Despite the prediction of a large number of plant peptides, their detection and imaging with spatial localization and chemical specificity is currently lacking. Here we analyzed the endogenous peptides and proteins in Medicago truncatula using matrix-assisted laser desorption/ionization (MALDI)-MSI. Hundreds of endogenous peptides and protein fragments were imaged, with interesting peptide spatial distribution changes observed between plants in different developmental stages.
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Affiliation(s)
- Erin Gemperline
- Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Caitlin Keller
- Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Dhileepkumar Jayaraman
- Department of Agronomy, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Junko Maeda
- Department of Agronomy, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Michael R Sussman
- Department of Biochemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Jean-Michel Ané
- Department of Agronomy, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.,Department of Bacteriology, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.,School of Pharmacy, University of Wisconsin-Madison , Madison, Wisconsin 53705, United States
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36
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Hu CK, Southey BR, Romanova EV, Maruska KP, Sweedler JV, Fernald RD. Identification of prohormones and pituitary neuropeptides in the African cichlid, Astatotilapia burtoni. BMC Genomics 2016; 17:660. [PMID: 27543050 PMCID: PMC4992253 DOI: 10.1186/s12864-016-2914-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 07/06/2016] [Indexed: 12/14/2022] Open
Abstract
Background Cichlid fishes have evolved remarkably diverse reproductive, social, and feeding behaviors. Cell-to-cell signaling molecules, notably neuropeptides and peptide hormones, are known to regulate these behaviors across vertebrates. This class of signaling molecules derives from prohormone genes that have undergone multiple duplications and losses in fishes. Whether and how subfunctionalization, neofunctionalization, or losses of neuropeptides and peptide hormones have contributed to fish behavioral diversity is largely unknown. Information on fish prohormones has been limited and is complicated by the whole genome duplication of the teleost ancestor. We combined bioinformatics, mass spectrometry-enabled peptidomics, and molecular techniques to identify the suite of neuropeptide prohormones and pituitary peptide products in Astatotilapia burtoni, a well-studied member of the diverse African cichlid clade. Results Utilizing the A. burtoni genome, we identified 148 prohormone genes, with 21 identified as a single copy and 39 with at least 2 duplicated copies. Retention of prohormone duplicates was therefore 41 %, which is markedly above previous reports for the genome-wide average in teleosts. Beyond the expected whole genome duplication, differences between cichlids and mammals can be attributed to gene loss in tetrapods and additional duplication after divergence. Mass spectrometric analysis of the pituitary identified 620 unique peptide sequences that were matched to 120 unique proteins. Finally, we used in situ hybridization to localize the expression of galanin, a prohormone with exceptional sequence divergence in cichlids, as well as the expression of a proopiomelanocortin, prohormone that has undergone an additional duplication in some bony fish lineages. Conclusion We characterized the A. burtoni prohormone complement. Two thirds of prohormone families contain duplications either from the teleost whole genome duplication or a more recent duplication. Our bioinformatic and mass spectrometric findings provide information on a major vertebrate clade that will further our understanding of the functional ramifications of these prohormone losses, duplications, and sequence changes across vertebrate evolution. In the context of the cichlid radiation, these findings will also facilitate the exploration of neuropeptide and peptide hormone function in behavioral diversity both within A. burtoni and across cichlid and other fish species. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2914-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Caroline K Hu
- Department of Biology, Stanford University, Stanford, CA, 94305, USA.,Present address: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Bruce R Southey
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Elena V Romanova
- Department of Chemistry and the Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Karen P Maruska
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Jonathan V Sweedler
- Department of Chemistry and the Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Russell D Fernald
- Department of Biology, Stanford University, Stanford, CA, 94305, USA.
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37
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Lombard-Banek C, Reddy S, Moody SA, Nemes P. Label-free Quantification of Proteins in Single Embryonic Cells with Neural Fate in the Cleavage-Stage Frog (Xenopus laevis) Embryo using Capillary Electrophoresis Electrospray Ionization High-Resolution Mass Spectrometry (CE-ESI-HRMS). Mol Cell Proteomics 2016; 15:2756-68. [PMID: 27317400 PMCID: PMC4974349 DOI: 10.1074/mcp.m115.057760] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 06/16/2016] [Indexed: 12/12/2022] Open
Abstract
Quantification of protein expression in single cells promises to advance a systems-level understanding of normal development. Using a bottom-up proteomic workflow and multiplexing quantification by tandem mass tags, we recently demonstrated relative quantification between single embryonic cells (blastomeres) in the frog (Xenopus laevis) embryo. In this study, we minimize derivatization steps to enhance analytical sensitivity and use label-free quantification (LFQ) for single Xenopus cells. The technology builds on a custom-designed capillary electrophoresis microflow-electrospray ionization high-resolution mass spectrometry platform and LFQ by MaxLFQ (MaxQuant). By judiciously tailoring performance to peptide separation, ionization, and data-dependent acquisition, we demonstrate an ∼75-amol (∼11 nm) lower limit of detection and quantification for proteins in complex cell digests. The platform enabled the identification of 438 nonredundant protein groups by measuring 16 ng of protein digest, or <0.2% of the total protein contained in a blastomere in the 16-cell embryo. LFQ intensity was validated as a quantitative proxy for protein abundance. Correlation analysis was performed to compare protein quantities between the embryo and n = 3 different single D11 blastomeres, which are fated to develop into the nervous system. A total of 335 nonredundant protein groups were quantified in union between the single D11 cells spanning a 4 log-order concentration range. LFQ and correlation analysis detected expected proteomic differences between the whole embryo and blastomeres, and also found translational differences between individual D11 cells. LFQ on single cells raises exciting possibilities to study gene expression in other cells and models to help better understand cell processes on a systems biology level.
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Affiliation(s)
| | - Sushma Reddy
- From the ‡Department of Chemistry and ¶Thomas Jefferson High School for Science and Technology, Alexandria, Virginia
| | - Sally A Moody
- §Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC
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38
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Voronina L, Masson A, Kamrath M, Schubert F, Clemmer D, Baldauf C, Rizzo T. Conformations of Prolyl–Peptide Bonds in the Bradykinin 1–5 Fragment in Solution and in the Gas Phase. J Am Chem Soc 2016; 138:9224-33. [DOI: 10.1021/jacs.6b04550] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Liudmila Voronina
- Laboratoire
de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCPM, Station 6, CH-1015 Lausanne, Switzerland
| | - Antoine Masson
- Laboratoire
de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCPM, Station 6, CH-1015 Lausanne, Switzerland
| | - Michael Kamrath
- Laboratoire
de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCPM, Station 6, CH-1015 Lausanne, Switzerland
| | - Franziska Schubert
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, D-14195 Berlin, Germany
| | - David Clemmer
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Carsten Baldauf
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, D-14195 Berlin, Germany
| | - Thomas Rizzo
- Laboratoire
de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCPM, Station 6, CH-1015 Lausanne, Switzerland
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39
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Secher A, Kelstrup CD, Conde-Frieboes KW, Pyke C, Raun K, Wulff BS, Olsen JV. Analytic framework for peptidomics applied to large-scale neuropeptide identification. Nat Commun 2016; 7:11436. [PMID: 27142507 PMCID: PMC4857386 DOI: 10.1038/ncomms11436] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 03/24/2016] [Indexed: 01/03/2023] Open
Abstract
Large-scale mass spectrometry-based peptidomics for drug discovery is relatively unexplored because of challenges in peptide degradation and identification following tissue extraction. Here we present a streamlined analytical pipeline for large-scale peptidomics. We developed an optimized sample preparation protocol to achieve fast, reproducible and effective extraction of endogenous peptides from sub-dissected organs such as the brain, while diminishing unspecific protease activity. Each peptidome sample was analysed by high-resolution tandem mass spectrometry and the resulting data set was integrated with publically available databases. We developed and applied an algorithm that reduces the peptide complexity for identification of biologically relevant peptides. The developed pipeline was applied to rat hypothalamus and identifies thousands of neuropeptides and their post-translational modifications, which is combined in a resource format for visualization, qualitative and quantitative analyses. Neuropeptide research is challenged by technical difficulties in identifying new bioactive peptides. Here the authors present an analytical pipeline for large-scale peptidomics applied to the rat hypothalamus, identifying thousands of endogenous neuropeptides and their post-translational modifications.
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Affiliation(s)
- Anna Secher
- Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3b, DK-2200 Copenhagen, Denmark.,Histology and Imaging, Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Maaloev, Denmark
| | - Christian D Kelstrup
- Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3b, DK-2200 Copenhagen, Denmark
| | | | - Charles Pyke
- Histology and Imaging, Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Maaloev, Denmark
| | - Kirsten Raun
- Incretin &Obesity Pharmacology, Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Maaloev, Denmark
| | - Birgitte S Wulff
- Incretin &Obesity Research, Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Maaloev, Denmark
| | - Jesper V Olsen
- Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3b, DK-2200 Copenhagen, Denmark
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40
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Abstract
Plant-omics is rapidly becoming an important field of study in the scientific community due to the urgent need to address many of the most important questions facing humanity today with regard to agriculture, medicine, biofuels, environmental decontamination, ecological sustainability, etc. High-performance mass spectrometry is a dominant tool for interrogating the metabolomes, peptidomes, and proteomes of a diversity of plant species under various conditions, revealing key insights into the functions and mechanisms of plant biochemistry.
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Affiliation(s)
- Erin Gemperline
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Caitlin Keller
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.,School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States
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41
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Ong TH, Romanova EV, Roberts-Galbraith RH, Yang N, Zimmerman TA, Collins JJ, Lee JE, Kelleher NL, Newmark PA, Sweedler JV. Mass Spectrometry Imaging and Identification of Peptides Associated with Cephalic Ganglia Regeneration in Schmidtea mediterranea. J Biol Chem 2016; 291:8109-20. [PMID: 26884331 PMCID: PMC4825013 DOI: 10.1074/jbc.m115.709196] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Indexed: 12/21/2022] Open
Abstract
Tissue regeneration is a complex process that involves a mosaic of molecules that vary spatially and temporally. Insights into the chemical signaling underlying this process can be achieved with a multiplex and untargeted chemical imaging method such as mass spectrometry imaging (MSI), which can enablede novostudies of nervous system regeneration. A combination of MSI and multivariate statistics was used to differentiate peptide dynamics in the freshwater planarian flatwormSchmidtea mediterraneaat different time points during cephalic ganglia regeneration. A protocol was developed to makeS. mediterraneatissues amenable for MSI. MS ion images of planarian tissue sections allow changes in peptides and unknown compounds to be followed as a function of cephalic ganglia regeneration. In conjunction with fluorescence imaging, our results suggest that even though the cephalic ganglia structure is visible after 6 days of regeneration, the original chemical composition of these regenerated structures is regained only after 12 days. Differences were observed in many peptides, such as those derived from secreted peptide 4 and EYE53-1. Peptidomic analysis further identified multiple peptides from various known prohormones, histone proteins, and DNA- and RNA-binding proteins as being associated with the regeneration process. Mass spectrometry data also facilitated the identification of a new prohormone, which we have named secreted peptide prohormone 20 (SPP-20), and is up-regulated during regeneration in planarians.
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Affiliation(s)
- Ta-Hsuan Ong
- From the Department of Chemistry, and the Beckman Institute
| | | | - Rachel H Roberts-Galbraith
- the Department of Cell and Developmental Biology, Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, and
| | - Ning Yang
- From the Department of Chemistry, and the Beckman Institute
| | | | - James J Collins
- the Department of Cell and Developmental Biology, Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, and
| | - Ji Eun Lee
- From the Department of Chemistry, and the Beckman Institute
| | - Neil L Kelleher
- the Departments of Chemistry and Molecular Biosciences, Proteomics Center of Excellence, Northwestern University, Evanston, Illinois 60611
| | - Phillip A Newmark
- the Department of Cell and Developmental Biology, Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, and
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42
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Thomas S, Hao L, Ricke WA, Li L. Biomarker discovery in mass spectrometry-based urinary proteomics. Proteomics Clin Appl 2016; 10:358-70. [PMID: 26703953 DOI: 10.1002/prca.201500102] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Revised: 12/05/2015] [Accepted: 12/21/2015] [Indexed: 01/03/2023]
Abstract
Urinary proteomics has become one of the most attractive topics in disease biomarker discovery. MS-based proteomic analysis has advanced continuously and emerged as a prominent tool in the field of clinical bioanalysis. However, only few protein biomarkers have made their way to validation and clinical practice. Biomarker discovery is challenged by many clinical and analytical factors including, but not limited to, the complexity of urine and the wide dynamic range of endogenous proteins in the sample. This article highlights promising technologies and strategies in the MS-based biomarker discovery process, including study design, sample preparation, protein quantification, instrumental platforms, and bioinformatics. Different proteomics approaches are discussed, and progresses in maximizing urinary proteome coverage and standardization are emphasized in this review. MS-based urinary proteomics has great potential in the development of noninvasive diagnostic assays in the future, which will require collaborative efforts between analytical scientists, systems biologists, and clinicians.
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Affiliation(s)
- Samuel Thomas
- Molecular and Environmental Toxicology Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Ling Hao
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
| | - William A Ricke
- Molecular and Environmental Toxicology Center, University of Wisconsin-Madison, Madison, WI, USA.,Department of Urology, University of Wisconsin-Madison, Madison, WI, USA
| | - Lingjun Li
- Molecular and Environmental Toxicology Center, University of Wisconsin-Madison, Madison, WI, USA.,School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA.,Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
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43
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Lombard-Banek C, Moody SA, Nemes P. Single-Cell Mass Spectrometry for Discovery Proteomics: Quantifying Translational Cell Heterogeneity in the 16-Cell Frog (Xenopus) Embryo. Angew Chem Int Ed Engl 2016; 55:2454-8. [PMID: 26756663 PMCID: PMC4755155 DOI: 10.1002/anie.201510411] [Citation(s) in RCA: 160] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 12/21/2015] [Indexed: 01/05/2023]
Abstract
We advance mass spectrometry from a cell population‐averaging tool to one capable of quantifying the expression of diverse proteins in single embryonic cells. Our instrument combines capillary electrophoresis (CE), electrospray ionization, and a tribrid ultrahigh‐resolution mass spectrometer (HRMS) to enable untargeted (discovery) proteomics with ca. 25 amol lower limit of detection. CE‐μESI‐HRMS enabled the identification of 500–800 nonredundant protein groups by measuring 20 ng, or <0.2% of the total protein content in single blastomeres that were isolated from the 16‐cell frog (Xenopus laevis) embryo, amounting to a total of 1709 protein groups identified between n=3 biological replicates. By quantifying ≈150 nonredundant protein groups between all blastomeres and replicate measurements, we found significant translational cell heterogeneity along multiple axes of the embryo at this very early stage of development when the transcriptional program of the embryo has yet to begin.
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Affiliation(s)
- Camille Lombard-Banek
- Department of Chemistry, W. M. Keck Institute for Proteomics Technology and Applications, The George Washington University, 800 22ndStreet, NW, Suite 4000, Washington, DC, 20052, USA
| | - Sally A Moody
- Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC, 20052, USA
| | - Peter Nemes
- Department of Chemistry, W. M. Keck Institute for Proteomics Technology and Applications, The George Washington University, 800 22ndStreet, NW, Suite 4000, Washington, DC, 20052, USA.
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44
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Lombard‐Banek C, Moody SA, Nemes P. Single‐Cell Mass Spectrometry for Discovery Proteomics: Quantifying Translational Cell Heterogeneity in the 16‐Cell Frog (
Xenopus
) Embryo. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201510411] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Camille Lombard‐Banek
- Department of Chemistry W. M. Keck Institute for Proteomics Technology and Applications The George Washington University 800 22ndStreet, NW, Suite 4000 Washington DC 20052 USA
| | - Sally A. Moody
- Department of Anatomy and Regenerative Biology The George Washington University Washington DC 20052 USA
| | - Peter Nemes
- Department of Chemistry W. M. Keck Institute for Proteomics Technology and Applications The George Washington University 800 22ndStreet, NW, Suite 4000 Washington DC 20052 USA
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45
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Tillmaand EG, Yang N, Kindt CAC, Romanova EV, Rubakhin SS, Sweedler JV. Peptidomics and Secretomics of the Mammalian Peripheral Sensory-Motor System. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:2051-2061. [PMID: 26392278 PMCID: PMC4655166 DOI: 10.1007/s13361-015-1256-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 07/30/2015] [Accepted: 08/10/2015] [Indexed: 06/01/2023]
Abstract
The dorsal root ganglion (DRG) and its anatomically and functionally associated spinal nerve and ventral and dorsal roots are important components of the peripheral sensory-motor system in mammals. The cells within these structures use a number of peptides as intercellular signaling molecules. We performed a variety of mass spectrometry (MS)-based characterizations of peptides contained within and secreted from these structures, and from isolated and cultured DRG cells. Liquid chromatography-Fourier transform MS was utilized in DRG and nerve peptidome analysis. In total, 2724 peptides from 296 proteins were identified in tissue extracts. Neuropeptides are among those detected, including calcitonin gene-related peptide I, little SAAS, and known hemoglobin-derived peptides. Solid phase extraction combined with direct matrix-assisted laser desorption/ionization time-of-flight MS was employed to investigate the secretome of these structures. A number of peptides were detected in the releasate from semi-intact preparations of DRGs and associated nerves, including neurofilament- and myelin basic protein-related peptides. A smaller set of analytes was observed in releasates from cultured DRG neurons. The peptide signals observed in the releasates have been mass-matched to those characterized and identified in homogenates of entire DRGs and associated nerves. This data aids our understanding of the chemical composition of the mammalian peripheral sensory-motor system, which is involved in key physiological functions such as nociception, thermoreception, itch sensation, and proprioception.
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Affiliation(s)
- Emily G Tillmaand
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Ning Yang
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Callie A C Kindt
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Elena V Romanova
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Stanislav S Rubakhin
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Jonathan V Sweedler
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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46
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Zhang Y, Buchberger A, Muthuvel G, Li L. Expression and distribution of neuropeptides in the nervous system of the crab Carcinus maenas and their roles in environmental stress. Proteomics 2015; 15:3969-79. [PMID: 26475201 DOI: 10.1002/pmic.201500256] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 10/07/2015] [Accepted: 10/12/2015] [Indexed: 01/05/2023]
Abstract
Environmental fluctuations, such as salinity, impose serious challenges to marine animal survival. Neuropeptides, signaling molecules involved in the regulation process, and the dynamic changes of their full complement in the stress response have yet to be investigated. Here, a MALDI-MS-based stable isotope labeling quantitation strategy was used to investigate the relationship between neuropeptide expression and adaptability of Carcinus maenas to various salinity levels, including high (60 parts per thousand [p.p.t.]) and low (0 p.p.t.) salinity, in both the crustacean pericardial organ (PO) and brain. Moreover, a high salinity stress time course study was conducted. MS imaging (MSI) of neuropeptide localization in C. maenas PO was also performed. As a result of salinity stress, multiple neuropeptide families exhibited changes in their relative abundances, including RFamides (e.g. APQGNFLRFamide), RYamides (e.g. SSFRVGGSRYamide), B-type allatostatins (AST-B; e.g. VPNDWAHFRGSWamide), and orcokinins (e.g. NFDEIDRSSFGFV). The MSI data revealed distribution differences in several neuropeptides (e.g. SGFYANRYamide) between color morphs, but salinity stress appeared to not have a major effect on the localization of the neuropeptides.
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Affiliation(s)
- Yuzhuo Zhang
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
| | - Amanda Buchberger
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Lingjun Li
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA.,Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
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47
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Ye H, Wang J, Zhang Z, Jia C, Schmerberg C, Catherman AD, Thomas PM, Kelleher NL, Li L. Defining the Neuropeptidome of the Spiny Lobster Panulirus interruptus Brain Using a Multidimensional Mass Spectrometry-Based Platform. J Proteome Res 2015; 14:4776-91. [PMID: 26390183 DOI: 10.1021/acs.jproteome.5b00627] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Decapod crustaceans are important animal models for neurobiologists due to their relatively simple nervous systems with well-defined neural circuits and extensive neuromodulation by a diverse set of signaling peptides. However, biochemical characterization of these endogenous neuropeptides is often challenging due to limited sequence information about these neuropeptide genes and the encoded preprohormones. By taking advantage of sequence homology in neuropeptides observed in related species using a home-built crustacean neuropeptide database, we developed a semi-automated sequencing strategy to characterize the neuropeptidome of Panulirus interruptus, an important aquaculture species, with few known neuropeptide preprohormone sequences. Our streamlined process searched the high mass accuracy and high-resolution data acquired on a LTQ-Orbitrap with a flexible algorithm in ProSight that allows for sequence discrepancy from reported sequences in our database, resulting in the detection of 32 neuropeptides, including 19 novel ones. We further improved the overall coverage to 51 neuropeptides with our multidimensional platform that employed multiple analytical techniques including dimethylation-assisted fragmentation, de novo sequencing using nanoliquid chromatography-electrospray ionization-quadrupole-time-of-flight (nanoLC-ESI-Q-TOF), direct tissue analysis, and mass spectrometry imaging on matrix-assisted laser desorption/ionization (MALDI)-TOF/TOF. The high discovery rate from this unsequenced model organism demonstrated the utility of our neuropeptide discovery pipeline and highlighted the advantage of utilizing multiple sequencing strategies. Collectively, our study expands the catalog of crustacean neuropeptides and more importantly presents an approach that can be adapted to exploring neuropeptidome from species that possess limited sequence information.
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Affiliation(s)
- Hui Ye
- State Key Laboratory of Natural Medicines, Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University , Nanjing 210009, China.,School of Pharmacy, University of Wisconsin-Madison , Madison, Wisconsin 53705, United States
| | | | - Zichuan Zhang
- School of Pharmacy, University of Wisconsin-Madison , Madison, Wisconsin 53705, United States
| | - Chenxi Jia
- School of Pharmacy, University of Wisconsin-Madison , Madison, Wisconsin 53705, United States
| | - Claire Schmerberg
- School of Pharmacy, University of Wisconsin-Madison , Madison, Wisconsin 53705, United States
| | - Adam D Catherman
- Departments of Chemistry and Molecular Biosciences, Proteomics Center of Excellence and Chemistry of Life Processes Institute, Northwestern University , 2145 North Sheridan Road, Evanston, Illinois 60208, United States
| | - Paul M Thomas
- Departments of Chemistry and Molecular Biosciences, Proteomics Center of Excellence and Chemistry of Life Processes Institute, Northwestern University , 2145 North Sheridan Road, Evanston, Illinois 60208, United States
| | - Neil L Kelleher
- Departments of Chemistry and Molecular Biosciences, Proteomics Center of Excellence and Chemistry of Life Processes Institute, Northwestern University , 2145 North Sheridan Road, Evanston, Illinois 60208, United States
| | - Lingjun Li
- School of Pharmacy, University of Wisconsin-Madison , Madison, Wisconsin 53705, United States.,School of Life Sciences, Tianjin University , No. 92 Weijin Road, Nankai District, Tianjin 300072, China
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48
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Schmidlin T, Boender AJ, Frese CK, Heck AJR, Adan RAH, Altelaar AFM. Diet-Induced Neuropeptide Expression: Feasibility of Quantifying Extended and Highly Charged Endogenous Peptide Sequences by Selected Reaction Monitoring. Anal Chem 2015; 87:9966-73. [DOI: 10.1021/acs.analchem.5b03334] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Thierry Schmidlin
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University and Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Arjen J. Boender
- Department
of Translational Neuroscience, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands
| | - Christian K. Frese
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University and Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Albert J. R. Heck
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University and Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Roger A. H. Adan
- Department
of Translational Neuroscience, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands
| | - A. F. Maarten Altelaar
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University and Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, The Netherlands
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