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Kervin TA, Wiseman BC, Overduin M. Phosphoinositide Recognition Sites Are Blocked by Metabolite Attachment. Front Cell Dev Biol 2021; 9:690461. [PMID: 34368138 PMCID: PMC8340361 DOI: 10.3389/fcell.2021.690461] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 06/18/2021] [Indexed: 12/16/2022] Open
Abstract
Membrane readers take part in trafficking and signaling processes by localizing proteins to organelle surfaces and transducing molecular information. They accomplish this by engaging phosphoinositides (PIs), a class of lipid molecules which are found in different proportions in various cellular membranes. The prototypes are the PX domains, which exhibit a range of specificities for PIs. Our meta-analysis indicates that recognition of membranes by PX domains is specifically controlled by modification of lysine and arginine residues including acetylation, hydroxyisobutyrylation, glycation, malonylation, methylation and succinylation of sidechains that normally bind headgroups of phospholipids including organelle-specific PI signals. Such metabolite-modulated residues in lipid binding elements are named MET-stops here to highlight their roles as erasers of membrane reader functions. These modifications are concentrated in the membrane binding sites of half of all 49 PX domains in the human proteome and correlate with phosphoregulatory sites, as mapped using the Membrane Optimal Docking Area (MODA) algorithm. As these motifs are mutated and modified in various cancers and the responsible enzymes serve as potential drug targets, the discovery of MET-stops as a widespread inhibitory mechanism may aid in the development of diagnostics and therapeutics aimed at the readers, writers and erasers of the PI code.
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Affiliation(s)
- Troy A Kervin
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Brittany C Wiseman
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.,Molecular and Cellular Biology, MacEwan University, Edmonton, AB, Canada.,SMALP Network, Edmonton, AB, Canada
| | - Michael Overduin
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.,SMALP Network, Edmonton, AB, Canada
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2
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Kervin TA, Overduin M. Regulation of the Phosphoinositide Code by Phosphorylation of Membrane Readers. Cells 2021; 10:cells10051205. [PMID: 34069055 PMCID: PMC8156045 DOI: 10.3390/cells10051205] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/07/2021] [Accepted: 05/09/2021] [Indexed: 02/07/2023] Open
Abstract
The genetic code that dictates how nucleic acids are translated into proteins is well known, however, the code through which proteins recognize membranes remains mysterious. In eukaryotes, this code is mediated by hundreds of membrane readers that recognize unique phosphatidylinositol phosphates (PIPs), which demark organelles to initiate localized trafficking and signaling events. The only superfamily which specifically detects all seven PIPs are the Phox homology (PX) domains. Here, we reveal that throughout evolution, these readers are universally regulated by the phosphorylation of their PIP binding surfaces based on our analysis of existing and modelled protein structures and phosphoproteomic databases. These PIP-stops control the selective targeting of proteins to organelles and are shown to be key determinants of high-fidelity PIP recognition. The protein kinases responsible include prominent cancer targets, underscoring the critical role of regulated membrane readership.
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Yang L, Tan W, Yang X, You Y, Wang J, Wen G, Zhong J. Sorting nexins: A novel promising therapy target for cancerous/neoplastic diseases. J Cell Physiol 2020; 236:3317-3335. [PMID: 33090492 DOI: 10.1002/jcp.30093] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/18/2020] [Accepted: 09/22/2020] [Indexed: 12/17/2022]
Abstract
Sorting nexins (SNXs) are a diverse group of cytoplasmic- and membrane-associated phosphoinositide-binding proteins containing the PX domain proteins. The function of SNX proteins in regulating intracellular protein trafficking consists of endocytosis, endosomal sorting, and endosomal signaling. Dysfunctions of SNX proteins are demonstrated to be involved in several cancerous/neoplastic diseases. Here, we review the accumulated evidence of the molecular structure and biological function of SNX proteins and discuss the regulatory role of SNX proteins in distinct cancerous/neoplastic diseases. SNX family proteins may be a valuable potential biomarker and therapeutic strategy for diagnostics and treatment of cancerous/neoplastic diseases.
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Affiliation(s)
- Lu Yang
- Hunan Province Key Laboratory of Tumor Cellular & Molecular Pathology, Cancer Research Institute, University of South China, Hengyang, Hunan, China
- Institute of Clinical Medicine, the First Affiliated Hospital of University of South China, Hengyang, Hunan, China
| | - Weihua Tan
- Institute of Clinical Medicine, the First Affiliated Hospital of University of South China, Hengyang, Hunan, China
- Emergency Department, the First Affiliated Hospital of University of South China, Hengyang, Hunan, China
| | - Xinzhi Yang
- Hunan Province Key Laboratory of Tumor Cellular & Molecular Pathology, Cancer Research Institute, University of South China, Hengyang, Hunan, China
- Institute of Clinical Medicine, the First Affiliated Hospital of University of South China, Hengyang, Hunan, China
| | - Yong You
- Research Lab of Translational Medicine, Hengyang Medical College, University of South China, Hengyang, Hunan, China
| | - Jing Wang
- Research Lab of Translational Medicine, Hengyang Medical College, University of South China, Hengyang, Hunan, China
| | - Gebo Wen
- Hunan Province Key Laboratory of Tumor Cellular & Molecular Pathology, Cancer Research Institute, University of South China, Hengyang, Hunan, China
- Institute of Clinical Medicine, the First Affiliated Hospital of University of South China, Hengyang, Hunan, China
| | - Jing Zhong
- Hunan Province Key Laboratory of Tumor Cellular & Molecular Pathology, Cancer Research Institute, University of South China, Hengyang, Hunan, China
- Institute of Clinical Medicine, the First Affiliated Hospital of University of South China, Hengyang, Hunan, China
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Vassilev B, Louhimo R, Ikonen E, Hautaniemi S. Language-Agnostic Reproducible Data Analysis Using Literate Programming. PLoS One 2016; 11:e0164023. [PMID: 27711123 PMCID: PMC5053501 DOI: 10.1371/journal.pone.0164023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 09/19/2016] [Indexed: 01/15/2023] Open
Abstract
A modern biomedical research project can easily contain hundreds of analysis steps and lack of reproducibility of the analyses has been recognized as a severe issue. While thorough documentation enables reproducibility, the number of analysis programs used can be so large that in reality reproducibility cannot be easily achieved. Literate programming is an approach to present computer programs to human readers. The code is rearranged to follow the logic of the program, and to explain that logic in a natural language. The code executed by the computer is extracted from the literate source code. As such, literate programming is an ideal formalism for systematizing analysis steps in biomedical research. We have developed the reproducible computing tool Lir (literate, reproducible computing) that allows a tool-agnostic approach to biomedical data analysis. We demonstrate the utility of Lir by applying it to a case study. Our aim was to investigate the role of endosomal trafficking regulators to the progression of breast cancer. In this analysis, a variety of tools were combined to interpret the available data: a relational database, standard command-line tools, and a statistical computing environment. The analysis revealed that the lipid transport related genes LAPTM4B and NDRG1 are coamplified in breast cancer patients, and identified genes potentially cooperating with LAPTM4B in breast cancer progression. Our case study demonstrates that with Lir, an array of tools can be combined in the same data analysis to improve efficiency, reproducibility, and ease of understanding. Lir is an open-source software available at github.com/borisvassilev/lir.
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Affiliation(s)
- Boris Vassilev
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- * E-mail:
| | - Riku Louhimo
- Research Programs Unit, Genome-Scale Biology, University of Helsinki, Helsinki, Finland
| | - Elina Ikonen
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Sampsa Hautaniemi
- Research Programs Unit, Genome-Scale Biology, University of Helsinki, Helsinki, Finland
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Fukuda M, Kameoka D, Torizawa T, Saitoh S, Yasutake M, Imaeda Y, Koga A, Mizutani A. Thermodynamic and fluorescence analyses to determine mechanisms of IgG1 stabilization and destabilization by arginine. Pharm Res 2013; 31:992-1001. [PMID: 24287623 DOI: 10.1007/s11095-013-1221-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 09/30/2013] [Indexed: 11/24/2022]
Abstract
PURPOSE To investigate mechanisms governing the stabilization and destabilization of immunoglobulin (IgG1) by arginine (Arg). METHODS The effects of Arg on the aggregation/degradation, thermodynamic stability, hydrophobicity, and aromatic residues of IgG1 were respectively investigated by size-exclusion chromatography, differential scanning calorimetry, probe fluorescence, and intrinsic fluorescence. RESULTS Arg monohydrochloride (Arg-HCl) suppressed IgG1 aggregation at near-neutral pH, but facilitated aggregation and degradation at acidic pH or at high storage temperature. Equimolar mixtures of Arg and aspartic acid (Asp) or glutamic acid (Glu) suppressed aggregation without facilitating degradation even at high temperature. Arg-HCl decreased the thermodynamic stability of IgG1 by enthalpic loss, which was counteracted by using Asp or Glu as a counterion for Arg. The suppression of aggregation by Arg-HCl was well correlated with the decrease in hydrophobicity of IgG1. The intrinsic fluorescence of IgG1 was unaffected by Arg-HCl. CONCLUSIONS Suppression of IgG1 aggregation can be attributed to the interaction between Arg and hydrophobic residues; on the other hand, facilitation of aggregation and degradation is presumably due to the interaction between Arg and some acidic residues, which could be competitively inhibited by simultaneously adding either Asp or Glu.
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Affiliation(s)
- Masakazu Fukuda
- Product Engineering Department, Chugai Pharmaceutical Co., Ltd., 5-5-1 Ukima, Kita-ku, Tokyo, 115-8543, Japan,
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Xu J, Xu T, Wu B, Ye Y, You X, Shu X, Pei D, Liu J. Structure of sorting nexin 11 (SNX11) reveals a novel extended phox homology (PX) domain critical for inhibition of SNX10-induced vacuolation. J Biol Chem 2013; 288:16598-16605. [PMID: 23615901 DOI: 10.1074/jbc.m112.449306] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Sorting nexins are phox homology (PX) domain-containing proteins involved in diverse intracellular endosomal trafficking pathways. The PX domain binds to certain phosphatidylinositols and is recruited to vesicles rich in these lipids. The structure of the PX domain is highly conserved, containing a three-stranded β-sheet, followed by three α-helices. Here, we report the crystal structures of truncated human SNX11 (sorting nexin 11). The structures reveal that SNX11 contains a novel PX domain, hereby named the extended PX (PXe) domain, with two additional α-helices at the C terminus. We demonstrate that these α-helices are indispensible for the in vitro functions of SNX11. We propose that this PXe domain is present in SNX10 and is responsible for the vacuolation activity of SNX10. Thus, this novel PXe domain constitutes a structurally and functionally important PX domain subfamily.
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Affiliation(s)
- Jinxin Xu
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530; School of Life Sciences, University of Science and Technology of China, Hefei 230026
| | - Tingting Xu
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530; School of Life Sciences, University of Science and Technology of China, Hefei 230026
| | - Bin Wu
- Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Yinghua Ye
- Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Xiaojuan You
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530
| | - Xiaodong Shu
- Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Duanqing Pei
- Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Jinsong Liu
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530; School of Life Sciences, University of Science and Technology of China, Hefei 230026.
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Abstract
Diverse biological processes including cell growth and survival require transient association of proteins with cellular membranes. A large number of these proteins are drawn to a bilayer through binding of their modular domains to phosphoinositide (PI) lipids. Seven PI isoforms are found to concentrate in distinct pools of intracellular membranes, and this lipid compartmentalization provides an efficient way for recruiting PI-binding proteins to specific cellular organelles. The atomic-resolution structures and membrane docking mechanisms of a dozen PI effectors have been elucidated in the last decade, offering insight into the molecular basis for regulation of the PI-dependent signaling pathways. In this chapter, I summarize the mechanistic aspects of deciphering the 'PI code' by the most common PI-recognizing domains and discuss similarities and differences in the membrane anchoring mechanisms.
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Affiliation(s)
- Tatiana G Kutateladze
- Department of Pharmacology, University of Colorado Denver School of Medicine, Aurora, CO 80045, USA.
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Insights into the PX (phox-homology) domain and SNX (sorting nexin) protein families: structures, functions and roles in disease. Biochem J 2011; 441:39-59. [DOI: 10.1042/bj20111226] [Citation(s) in RCA: 212] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The mammalian genome encodes 49 proteins that possess a PX (phox-homology) domain, responsible for membrane attachment to organelles of the secretory and endocytic system via binding of phosphoinositide lipids. The PX domain proteins, most of which are classified as SNXs (sorting nexins), constitute an extremely diverse family of molecules that play varied roles in membrane trafficking, cell signalling, membrane remodelling and organelle motility. In the present review, we present an overview of the family, incorporating recent functional and structural insights, and propose an updated classification of the proteins into distinct subfamilies on the basis of these insights. Almost all PX domain proteins bind PtdIns3P and are recruited to early endosomal membranes. Although other specificities and localizations have been reported for a select few family members, the molecular basis for binding to other lipids is still not clear. The PX domain is also emerging as an important protein–protein interaction domain, binding endocytic and exocytic machinery, transmembrane proteins and many other molecules. A comprehensive survey of the molecular interactions governed by PX proteins highlights the functional diversity of the family as trafficking cargo adaptors and membrane-associated scaffolds regulating cell signalling. Finally, we examine the mounting evidence linking PX proteins to different disorders, in particular focusing on their emerging importance in both pathogen invasion and amyloid production in Alzheimer's disease.
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Abstract
Phosphoinositide (PI) lipids are essential components of eukaryotic cell membranes. They are produced by mono-, bis- and trisphosphorylation of the inositol headgroup of phosphatidylinositol (PtdIns) and are concentrated in separate pools of cytosolic membranes. PIs serve as markers of the cell compartments and form unique docking sites for protein effectors. Collectively, seven known PIs, the protein effectors that bind them and enzymes that generate or modify PIs compose a remarkably complex protein-lipid signaling network. A number of cytosolic proteins contain one or several effector modules capable of recognizing individual PIs and recruiting the host proteins to distinct intracellular compartment. The recently determined atomic-resolution structures and membrane-targeting mechanisms of a dozen PI effectors have provided insights into the molecular basis for regulation of endocytic membrane trafficking and signaling. In this review, I highlight the structural aspects of the deciphering of the 'PI code' by the most common PI-recognizing effectors and discuss the mechanistic details of their membrane anchoring.
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Koharudin LMI, Furey W, Liu H, Liu YJ, Gronenborn AM. The phox domain of sorting nexin 5 lacks phosphatidylinositol 3-phosphate (PtdIns(3)P) specificity and preferentially binds to phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2). J Biol Chem 2009; 284:23697-707. [PMID: 19553671 PMCID: PMC2749144 DOI: 10.1074/jbc.m109.008995] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Revised: 06/08/2009] [Indexed: 11/06/2022] Open
Abstract
Subcellular retrograde transport of cargo receptors from endosomes to the trans-Golgi network is critically involved in a broad range of physiological and pathological processes and highly regulated by a genetically conserved heteropentameric complex, termed retromer. Among the retromer components identified in mammals, sorting nexin 5 and 1 (SNX5; SNX1) have recently been found to interact, possibly controlling the membrane binding specificity of the complex. To elucidate how the unique sequence features of the SNX5 phox domain (SNX5-PX) influence retrograde transport, we have determined the SNX5-PX structure by NMR and x-ray crystallography at 1.5 A resolution. Although the core fold of SNX5-PX resembles that of other known PX domains, we found novel structural features exclusive to SNX5-PX. It is most noteworthy that in SNX5-PX, a long helical hairpin is added to the core formed by a new alpha2'-helix and a much longer alpha3-helix. This results in a significantly altered overall shape of the protein. In addition, the unique double PXXP motif is tightly packed against the rest of the protein, rendering this part of the structure compact, occluding parts of the putative phosphatidylinositol (PtdIns) binding pocket. The PtdIns binding and specificity of SNX5-PX was evaluated by NMR titrations with eight different PtdIns and revealed that SNX5-PX preferentially and specifically binds to phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P(2)). The distinct structural and PtdIns binding characteristics of SNX5-PX impart specific properties on SNX5, influencing retromer-mediated regulation of retrograde trafficking of transmembrane cargo receptors.
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Affiliation(s)
| | - William Furey
- Pharmacology and Chemical Biology
- the Biocrystallography Laboratory, Veterans Affairs Medical Center, Pittsburgh, Pennsylvania 15240
| | | | - Yong-Jian Liu
- Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260 and
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Zhou Q, Wang J, Huang L, Nie W, Wang J, Liu Y, Zhao X, Yang F, Wang W. Neo-sex chromosomes in the black muntjac recapitulate incipient evolution of mammalian sex chromosomes. Genome Biol 2008; 9:R98. [PMID: 18554412 PMCID: PMC2481430 DOI: 10.1186/gb-2008-9-6-r98] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2007] [Revised: 03/04/2008] [Accepted: 06/14/2008] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The regular mammalian X and Y chromosomes diverged from each other at least 166 to 148 million years ago, leaving few traces of their early evolution, including degeneration of the Y chromosome and evolution of dosage compensation. RESULTS We studied the intriguing case of black muntjac, in which a recent X-autosome fusion and a subsequent large autosomal inversion within just the past 0.5 million years have led to inheritance patterns identical to the traditional X-Y (neo-sex chromosomes). We compared patterns of genome evolution in 35-kilobase noncoding regions and 23 gene pairs on the homologous neo-sex chromosomes. We found that neo-Y alleles have accumulated more mutations, comprising a wide variety of mutation types, which indicates cessation of recombination and is consistent with an ongoing neo-Y degeneration process. Putative deleterious mutations were observed in coding regions of eight investigated genes as well as cis-regulatory regions of two housekeeping genes. In vivo assays characterized a neo-Y insertion in the promoter of the CLTC gene that causes a significant reduction in allelic expression. A neo-Y-linked deletion in the 3'-untranslated region of gene SNX22 abolished a microRNA target site. Finally, expression analyses revealed complex patterns of expression divergence between neo-Y and neo-X alleles. CONCLUSION The nascent neo-sex chromosome system of black muntjacs is a valuable model in which to study the evolution of sex chromosomes in mammals. Our results illustrate the degeneration scenarios in various genomic regions. Of particular importance, we report--for the first time--that regulatory mutations were probably able to accelerate the degeneration process of Y and contribute to further evolution of dosage compensation.
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Affiliation(s)
- Qi Zhou
- CAS-Max Planck Junior Research Group, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences (CAS), 32# Jiao-chang Road, Kunming, Yunnan 650223, People's Republic of China
- Graduate School of Chinese Academy Sciences, 19# Yu-quan Road, Beijing 100039, People's Republic of China
| | - Jun Wang
- The Institute of Human Genetics, University of Aarhus, Nordre Ringgade 1, DK-8000 Aarhus C, Denmark
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark
- Beijing Genomics Institute, Bei-shan Road, Shenzhen 518083, People's Republic of China
| | - Ling Huang
- Graduate School of Chinese Academy Sciences, 19# Yu-quan Road, Beijing 100039, People's Republic of China
- Kunming Cell Bank, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 32# Jiao-chang Road, Kunming, Yunnan 650223, People's Republic of China
| | - Wenhui Nie
- Kunming Cell Bank, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 32# Jiao-chang Road, Kunming, Yunnan 650223, People's Republic of China
| | - Jinhuan Wang
- Kunming Cell Bank, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 32# Jiao-chang Road, Kunming, Yunnan 650223, People's Republic of China
| | - Yan Liu
- Graduate School of Chinese Academy Sciences, 19# Yu-quan Road, Beijing 100039, People's Republic of China
- Kunming Cell Bank, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 32# Jiao-chang Road, Kunming, Yunnan 650223, People's Republic of China
| | - Xiangyi Zhao
- CAS-Max Planck Junior Research Group, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences (CAS), 32# Jiao-chang Road, Kunming, Yunnan 650223, People's Republic of China
| | - Fengtang Yang
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Ickleton Road, Hinxton, Cambridge, CB10 1SA, UK
| | - Wen Wang
- CAS-Max Planck Junior Research Group, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences (CAS), 32# Jiao-chang Road, Kunming, Yunnan 650223, People's Republic of China
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Hautbergue GM, Golovanov AP. Increasing the sensitivity of cryoprobe protein NMR experiments by using the sole low-conductivity arginine glutamate salt. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2008; 191:335-339. [PMID: 18207440 DOI: 10.1016/j.jmr.2007.12.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Revised: 12/06/2007] [Accepted: 12/21/2007] [Indexed: 05/25/2023]
Abstract
Decrease in experimental sensitivity of cryoprobe experiments for salty samples, attributed to increased sample conductivity, has been a long-standing issue in protein NMR. Salt concentration can not be simply reduced as this often leads to protein aggregation. A simple and inexpensive solution to this problem is demonstrated here. We show that even for proteins prone to aggregation, the traditional solubilizing salt, 100mM NaCl, can be completely replaced by 50mM l-Arg and l-Glu. This replacement simultaneously reduces the sample conductivity and improves protein solubility. Up to a 6-fold overall increase in experimental sensitivity was achieved, in comparison with the traditional salty buffer. At constant protein concentration up to 2-fold increase in sensitivity was observed. The lengths of the proton pi/2 pulses were also significantly decreased, up to the level typical for non-salty samples in water.
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Affiliation(s)
- Guillaume M Hautbergue
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
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