1
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Lu G, Tran VNH, Wu W, Ma M, Li L. Neuropeptidomics of the American Lobster Homarus americanus. J Proteome Res 2024; 23:1757-1767. [PMID: 38644788 PMCID: PMC11118981 DOI: 10.1021/acs.jproteome.3c00925] [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: 04/23/2024]
Abstract
The American lobster, Homarus americanus, is not only of considerable economic importance but has also emerged as a premier model organism in neuroscience research. Neuropeptides, an important class of cell-to-cell signaling molecules, play crucial roles in a wide array of physiological and psychological processes. Leveraging the recently sequenced high-quality draft genome of the American lobster, our study sought to profile the neuropeptidome of this model organism. Employing advanced mass spectrometry techniques, we identified 24 neuropeptide precursors and 101 unique mature neuropeptides in Homarus americanus. Intriguingly, 67 of these neuropeptides were discovered for the first time. Our findings provide a comprehensive overview of the peptidomic attributes of the lobster's nervous system and highlight the tissue-specific distribution of these neuropeptides. Collectively, this research not only enriches our understanding of the neuronal complexities of the American lobster but also lays a foundation for future investigations into the functional roles that these peptides play in crustacean species. The mass spectrometry data have been deposited in the PRIDE repository with the identifier PXD047230.
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Affiliation(s)
- Gaoyuan Lu
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Vu Ngoc Huong Tran
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Wenxin Wu
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Min Ma
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Lingjun Li
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, United States
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, United States
- Lachman Institute for Pharmaceutical Development, School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, United States
- Wisconsin Center for NanoBioSystems, School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, United States
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2
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Schrader M. Origins, Technological Advancement, and Applications of Peptidomics. Methods Mol Biol 2024; 2758:3-47. [PMID: 38549006 DOI: 10.1007/978-1-0716-3646-6_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
Peptidomics is the comprehensive characterization of peptides from biological sources instead of heading for a few single peptides in former peptide research. Mass spectrometry allows to detect a multitude of peptides in complex mixtures and thus enables new strategies leading to peptidomics. The term was established in the year 2001, and up to now, this new field has grown to over 3000 publications. Analytical techniques originally developed for fast and comprehensive analysis of peptides in proteomics were specifically adjusted for peptidomics. Although it is thus closely linked to proteomics, there are fundamental differences with conventional bottom-up proteomics. Fundamental technological advancements of peptidomics since have occurred in mass spectrometry and data processing, including quantification, and more slightly in separation technology. Different strategies and diverse sources of peptidomes are mentioned by numerous applications, such as discovery of neuropeptides and other bioactive peptides, including the use of biochemical assays. Furthermore, food and plant peptidomics are introduced similarly. Additionally, applications with a clinical focus are included, comprising biomarker discovery as well as immunopeptidomics. This overview extensively reviews recent methods, strategies, and applications including links to all other chapters of this book.
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Affiliation(s)
- Michael Schrader
- Department of Bioengineering Sciences, Weihenstephan-Tr. University of Applied Sciences, Freising, Germany.
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3
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Schrader M, Fricker LD. Current Challenges and Future Directions in Peptidomics. Methods Mol Biol 2024; 2758:485-498. [PMID: 38549031 DOI: 10.1007/978-1-0716-3646-6_26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
The field of peptidomics has been under development since its start more than 20 years ago. In this chapter we provide a personal outlook for future directions in this field. The applications of peptidomics technologies are spreading more and more from classical research of peptide hormones and neuropeptides towards commercial applications in plant and food-science. Many clinical applications have been developed to analyze the complexity of biofluids, which are being addressed with new instrumentation, automization, and data processing. Additionally, the newly developed field of immunopeptidomics is showing promise for cancer therapies. In conclusion, peptidomics will continue delivering important information in classical fields like neuropeptides and peptide hormones, benefiting from improvements in state-of-the-art technologies. Moreover, new directions of research such as immunopeptidomics will further complement classical omics technologies and may become routine clinical procedures. Taken together, discoveries of new substances, networks, and applications of peptides can be expected in different disciplines.
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Affiliation(s)
- Michael Schrader
- Department of Bioengineering Sciences, Weihenstephan-Tr. University of Applied Sciences, Freising, Germany.
| | - Lloyd D Fricker
- Departments of Molecular Pharmacology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
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4
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Wehrli P, Ge J, Michno W, Koutarapu S, Dreos A, Jha D, Zetterberg H, Blennow K, Hanrieder J. Correlative Chemical Imaging and Spatial Chemometrics Delineate Alzheimer Plaque Heterogeneity at High Spatial Resolution. JACS AU 2023; 3:762-774. [PMID: 37006756 PMCID: PMC10052239 DOI: 10.1021/jacsau.2c00492] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 06/19/2023]
Abstract
We present a novel, correlative chemical imaging strategy based on multimodal matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI), hyperspectral microscopy, and spatial chemometrics. Our workflow overcomes challenges associated with correlative MSI data acquisition and alignment by implementing 1 + 1-evolutionary image registration for precise geometric alignment of multimodal imaging data and their integration in a common, truly multimodal imaging data matrix with maintained MSI resolution (10 μm). This enabled multivariate statistical modeling of multimodal imaging data using a novel multiblock orthogonal component analysis approach to identify covariations of biochemical signatures between and within imaging modalities at MSI pixel resolution. We demonstrate the method's potential through its application toward delineating chemical traits of Alzheimer's disease (AD) pathology. Here, trimodal MALDI MSI of transgenic AD mouse brain delineates beta-amyloid (Aβ) plaque-associated co-localization of lipids and Aβ peptides. Finally, we establish an improved image fusion approach for correlative MSI and functional fluorescence microscopy. This allowed for high spatial resolution (300 nm) prediction of correlative, multimodal MSI signatures toward distinct amyloid structures within single plaque features critically implicated in Aβ pathogenicity.
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Affiliation(s)
- Patrick
M. Wehrli
- Department
of Psychiatry and Neurochemistry, Institute
of Neuroscience and Physiology, Sahlgrenska Academy, University of
Gothenburg, Mölndal 431 80, Sweden
| | - Junyue Ge
- Clinical
Neurochemistry Laboratory, Sahlgrenska University
Hospital Mölndal, Mölndal 431 80, Sweden
| | - Wojciech Michno
- Department
of Psychiatry and Neurochemistry, Institute
of Neuroscience and Physiology, Sahlgrenska Academy, University of
Gothenburg, Mölndal 431 80, Sweden
| | - Srinivas Koutarapu
- Department
of Psychiatry and Neurochemistry, Institute
of Neuroscience and Physiology, Sahlgrenska Academy, University of
Gothenburg, Mölndal 431 80, Sweden
| | - Ambra Dreos
- Department
of Psychiatry and Neurochemistry, Institute
of Neuroscience and Physiology, Sahlgrenska Academy, University of
Gothenburg, Mölndal 431 80, Sweden
| | - Durga Jha
- Department
of Psychiatry and Neurochemistry, Institute
of Neuroscience and Physiology, Sahlgrenska Academy, University of
Gothenburg, Mölndal 431 80, Sweden
| | - Henrik Zetterberg
- Department
of Psychiatry and Neurochemistry, Institute
of Neuroscience and Physiology, Sahlgrenska Academy, University of
Gothenburg, Mölndal 431 80, Sweden
- Clinical
Neurochemistry Laboratory, Sahlgrenska University
Hospital Mölndal, Mölndal 431 80, Sweden
- Department
of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London WC1N 3BG, U.K.
- U.
K. Dementia Research Institute at University College London, London WC1N 3BG, U.K.
- Hong
Kong Center for Neurodegenerative Diseases, Sha Tin, N.T. 1512-1518, Hong Kong, China
| | - Kaj Blennow
- Department
of Psychiatry and Neurochemistry, Institute
of Neuroscience and Physiology, Sahlgrenska Academy, University of
Gothenburg, Mölndal 431 80, Sweden
- Clinical
Neurochemistry Laboratory, Sahlgrenska University
Hospital Mölndal, Mölndal 431 80, Sweden
| | - Jörg Hanrieder
- Department
of Psychiatry and Neurochemistry, Institute
of Neuroscience and Physiology, Sahlgrenska Academy, University of
Gothenburg, Mölndal 431 80, Sweden
- Clinical
Neurochemistry Laboratory, Sahlgrenska University
Hospital Mölndal, Mölndal 431 80, Sweden
- Department
of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London WC1N 3BG, U.K.
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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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6
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Anapindi KDB, Romanova EV, Checco JW, Sweedler JV. Mass Spectrometry Approaches Empowering Neuropeptide Discovery and Therapeutics. Pharmacol Rev 2022; 74:662-679. [PMID: 35710134 DOI: 10.1124/pharmrev.121.000423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The discovery of insulin in the early 1900s ushered in the era of research related to peptides acting as hormones and neuromodulators, among other regulatory roles. These essential gene products are found in all organisms, from the most primitive to the most evolved, and carry important biologic information that coordinates complex physiology and behavior; their misregulation has been implicated in a variety of diseases. The evolutionary origins of at least 30 neuropeptide signaling systems have been traced to the common ancestor of protostomes and deuterostomes. With the use of relevant animal models and modern technologies, we can gain mechanistic insight into orthologous and paralogous endogenous peptides and translate that knowledge into medically relevant insights and new treatments. Groundbreaking advances in medicine and basic science influence how signaling peptides are defined today. The precise mechanistic pathways for over 100 endogenous peptides in mammals are now known and have laid the foundation for multiple drug development pipelines. Peptide biologics have become valuable drugs due to their unique specificity and biologic activity, lack of toxic metabolites, and minimal undesirable interactions. This review outlines modern technologies that enable neuropeptide discovery and characterization, and highlights lessons from nature made possible by neuropeptide research in relevant animal models that is being adopted by the pharmaceutical industry. We conclude with a brief overview of approaches/strategies for effective development of peptides as drugs. SIGNIFICANCE STATEMENT: Neuropeptides, an important class of cell-cell signaling molecules, are involved in maintaining a range of physiological functions. Since the discovery of insulin's activity, over 100 bioactive peptides and peptide analogs have been used as therapeutics. Because these are complex molecules not easily predicted from a genome and their activity can change with subtle chemical modifications, mass spectrometry (MS) has significantly empowered peptide discovery and characterization. This review highlights contributions of MS-based research towards the development of therapeutic peptides.
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Affiliation(s)
- Krishna D B Anapindi
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois (K.D.B.A., E.V.R., J.V.S.) and Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska (J.W.C.)
| | - Elena V Romanova
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois (K.D.B.A., E.V.R., J.V.S.) and Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska (J.W.C.)
| | - James W Checco
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois (K.D.B.A., E.V.R., J.V.S.) and Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska (J.W.C.)
| | - Jonathan V Sweedler
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois (K.D.B.A., E.V.R., J.V.S.) and Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska (J.W.C.)
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7
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De La Toba EA, Bell SE, Romanova EV, Sweedler JV. Mass Spectrometry Measurements of Neuropeptides: From Identification to Quantitation. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2022; 15:83-106. [PMID: 35324254 DOI: 10.1146/annurev-anchem-061020-022048] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Neuropeptides (NPs), a unique class of neuronal signaling molecules, participate in a variety of physiological processes and diseases. Quantitative measurements of NPs provide valuable information regarding how these molecules are differentially regulated in a multitude of neurological, metabolic, and mental disorders. Mass spectrometry (MS) has evolved to become a powerful technique for measuring trace levels of NPs in complex biological tissues and individual cells using both targeted and exploratory approaches. There are inherent challenges to measuring NPs, including their wide endogenous concentration range, transport and postmortem degradation, complex sample matrices, and statistical processing of MS data required for accurate NP quantitation. This review highlights techniques developed to address these challenges and presents an overview of quantitative MS-based measurement approaches for NPs, including the incorporation of separation methods for high-throughput analysis, MS imaging for spatial measurements, and methods for NP quantitation in single neurons.
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Affiliation(s)
- Eduardo A De La Toba
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois, USA;
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Sara E Bell
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois, USA;
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Elena V Romanova
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois, USA;
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Jonathan V Sweedler
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois, USA;
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
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8
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Munley KM, Wade KL, Pradhan DS. Uncovering the seasonal brain: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) as a biochemical approach for studying seasonal social behaviors. Horm Behav 2022; 142:105161. [PMID: 35339904 DOI: 10.1016/j.yhbeh.2022.105161] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 03/12/2022] [Accepted: 03/14/2022] [Indexed: 11/17/2022]
Abstract
Many animals show pronounced changes in physiology and behavior across the annual cycle, and these adaptations enable individuals to prioritize investing in the neuroendocrine mechanisms underlying reproduction and/or survival based on the time of year. While prior research has offered valuable insight into how seasonal variation in neuroendocrine processes regulates social behavior, the majority of these studies have investigated how a single hormone influences a single behavioral phenotype. Given that hormones are synthesized and metabolized via complex biochemical pathways and often act in concert to control social behavior, these approaches provide a limited view of how hormones regulate seasonal changes in behavior. In this review, we discuss how seasonal influences on hormones, the brain, and social behavior can be studied using liquid chromatography-tandem mass spectrometry (LC-MS/MS), an analytical chemistry technique that enables researchers to simultaneously quantify the concentrations of multiple hormones and the activities of their synthetic enzymes. First, we examine studies that have investigated seasonal plasticity in brain-behavior interactions, specifically by focusing on how two groups of hormones, sex steroids and nonapeptides, regulate sexual and aggressive behavior. Then, we explain the operations of LC-MS/MS, highlight studies that have used LC-MS/MS to study the neuroendocrine mechanisms underlying social behavior, both within and outside of a seasonal context, and discuss potential applications for LC-MS/MS in the field of behavioral neuroendocrinology. We propose that this cutting-edge technology will provide a more comprehensive understanding of how the multitude of hormones that comprise complex neuroendocrine networks affect seasonal variation in the brain and behavior.
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Affiliation(s)
- Kathleen M Munley
- Department of Biology and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA.
| | - Kristina L Wade
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, USA
| | - Devaleena S Pradhan
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, USA
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9
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Pathmasiri KC, Nguyen TTA, Khamidova N, Cologna SM. Mass spectrometry-based lipid analysis and imaging. CURRENT TOPICS IN MEMBRANES 2021; 88:315-357. [PMID: 34862030 DOI: 10.1016/bs.ctm.2021.10.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mass spectrometry imaging (MSI) is a powerful tool for in situ mapping of analytes across a sample. With growing interest in lipid biochemistry, the ability to perform such mapping without antibodies has opened many opportunities for MSI and lipid analysis. Herein, we discuss the basics of MSI with particular emphasis on MALDI mass spectrometry and lipid analysis. A discussion of critical advancements as well as protocol details are provided to the reader. In addition, strategies for improving the detection of lipids, as well as applications in biomedical research, are presented.
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Affiliation(s)
- Koralege C Pathmasiri
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, United States
| | - Thu T A Nguyen
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, United States
| | - Nigina Khamidova
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, United States
| | - Stephanie M Cologna
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, United States; Laboratory of Integrated Neuroscience, University of Illinois at Chicago, Chicago, IL, United States.
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10
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Smith SJ. Transcriptomic evidence for dense peptidergic networks within forebrains of four widely divergent tetrapods. Curr Opin Neurobiol 2021; 71:100-109. [PMID: 34775262 DOI: 10.1016/j.conb.2021.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 09/21/2021] [Accepted: 09/27/2021] [Indexed: 12/15/2022]
Abstract
The primary function common to every neuron is communication with other neurons. Such cell-cell signaling can take numerous forms, including fast synaptic transmission and slower neuromodulation via secreted messengers, such as neuropeptides, dopamine, and many other diffusible small molecules. Individual neurons are quite diverse, however, in all particulars of both synaptic and neuromodulatory communication. Neuron classification schemes have therefore proven very useful in exploring the emergence of network function, behavior, and cognition from the communication functions of individual neurons. Recently published single-cell mRNA sequencing data and corresponding transcriptomic neuron classifications from turtle, songbird, mouse, and human provide evidence for a long evolutionary history and adaptive significance of localized peptidergic signaling. Across all four species, sets of at least twenty orthologous cognate pairs of neuropeptide precursor protein and receptor genes are expressed in individually sparse but heavily overlapping patterns suggesting that all forebrain neuron types are densely interconnected by local peptidergic signals.
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11
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Andrews WT, Bickner AN, Tobias F, Ryan KA, Bruening ML, Hummon AB. Electroblotting through Enzymatic Membranes to Enhance Molecular Tissue Imaging. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1689-1699. [PMID: 34110793 PMCID: PMC9241434 DOI: 10.1021/jasms.1c00046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
MALDI-TOF mass spectrometry imaging (MSI) is a powerful tool for studying biomolecule localization in tissue. Protein distributions in tissue provide important histological information; however, large proteins exhibit a high limit of detection in MALDI-MS when compared to their corresponding smaller proteolytic peptides. As a result, several techniques have emerged to digest proteins into more detectable peptides for imaging. Digestion is typically accomplished through trypsin deposition on the tissue, but this technique increases the complexity of the tissue microenvironment, which can limit the number of detectable species. This proof-of-principle study explores tryptic tissue digestion during electroblotting through a trypsin-containing membrane. This approach actively extracts and enzymatically digests proteins from mouse brain tissue sections while simultaneously reducing the complexity of the tissue microenvironment (compared to trypsin deposition on the surface) to obtain an increased number of detectable peptide fragments. The method does not greatly compromise spatial location or require expensive devices to uniformly deposit trypsin on tissue. Using electrodigestion through membranes, we detected and tentatively identified several tryptic peptides that were not observed after on-tissue digestion. Moreover, the use of pepsin rather than trypsin in digestion membranes allows extraction and digestion at low pH to detect peptides from a complementary subset of tissue proteins. Future studies will aim to further improve the method, including changing the substrate membrane to increase spatial resolution and the number of detected peptides.
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Affiliation(s)
| | | | - Fernando Tobias
- Department of Chemistry and Biochemistry, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, United States
| | | | | | - Amanda B Hummon
- Department of Chemistry and Biochemistry, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, United States
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12
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Veenstra T. Current Methods for Mass Spectrometric Analysis of Intact Proteins and Peptides. Curr Protein Pept Sci 2021; 22:90-91. [PMID: 33998987 DOI: 10.2174/138920372202210308153805] [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]
Affiliation(s)
- Timothy Veenstra
- School of Pharmacy Cedarville University Cedarville, OH 45314, United States
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