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Wang P, Zhang Q, Li S, Cheng B, Xue H, Wei Z, Shao T, Liu ZX, Cheng H, Wang Z. iCysMod: an integrative database for protein cysteine modifications in eukaryotes. Brief Bioinform 2021; 22:6066620. [PMID: 33406221 DOI: 10.1093/bib/bbaa400] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/23/2020] [Accepted: 12/07/2020] [Indexed: 01/06/2023] Open
Abstract
As important post-translational modifications, protein cysteine modifications (PCMs) occurring at cysteine thiol group play critical roles in the regulation of various biological processes in eukaryotes. Due to the rapid advancement of high-throughput proteomics technologies, a large number of PCM events have been identified but remain to be curated. Thus, an integrated resource of eukaryotic PCMs will be useful for the research community. In this work, we developed an integrative database for protein cysteine modifications in eukaryotes (iCysMod), which curated and hosted 108 030 PCM events for 85 747 experimentally identified sites on 31 483 proteins from 48 eukaryotes for 8 types of PCMs, including oxidation, S-nitrosylation (-SNO), S-glutathionylation (-SSG), disulfide formation (-SSR), S-sulfhydration (-SSH), S-sulfenylation (-SOH), S-sulfinylation (-SO2H) and S-palmitoylation (-S-palm). Then, browse and search options were provided for accessing the dataset, while various detailed information about the PCM events was well organized for visualization. With human dataset in iCysMod, the sequence features around the cysteine modification sites for each PCM type were analyzed, and the results indicated that various types of PCMs presented distinct sequence recognition preferences. Moreover, different PCMs can crosstalk with each other to synergistically orchestrate specific biological processes, and 37 841 PCM events involved in 119 types of PCM co-occurrences at the same cysteine residues were finally obtained. Taken together, we anticipate that the database of iCysMod would provide a useful resource for eukaryotic PCMs to facilitate related researches, while the online service is freely available at http://icysmod.omicsbio.info.
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Affiliation(s)
- Panqin Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Qingfeng Zhang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Shihua Li
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Ben Cheng
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Han Xue
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Zhen Wei
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Tian Shao
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Ze-Xian Liu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Han Cheng
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Zhenlong Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
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Juhász J, Gáspári Z, Pongor S. Structure and Oxidative Folding of AAI, the Major Alfa-Amylase Inhibitor From Amaranth Seeds. Front Chem 2020; 8:180. [PMID: 32257998 PMCID: PMC7090091 DOI: 10.3389/fchem.2020.00180] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 02/26/2020] [Indexed: 11/30/2022] Open
Abstract
AAI, the major alpha-amylase inhibitor (AAI) present in the seeds of the Mexican crop plant Amaranthus hypocondriacus is a 32-residue-long polypeptide with three disulfide bridges. Its structure is most closely related to the plant amylase inhibitor subfamily of knottins characterized by a topological knot formed by one disulfide bridge threading through a loop formed by the peptide chain as well as a short three-stranded beta sandwich core. AAI is specific against insect amylases and does not act on corresponding human or mammalian enzymes. It was found that the oxidative folding of AAI seems to follow a hirudine-like pathway with many non-native intermediates, but notably it proceeds through a major folding intermediate (MFI) that contains a vicinal disulfide bridge. Based on a review of the pertinent literature, the known vicinal disulfides in native proteins as well as well as the network of disulfide interchanges, we propose that MFI is a kinetic trap corresponding to a compact molten globule-like state which constrains the peptide chain to a smaller number of conformations that in turn can be rapidly funneled toward the native state.
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Affiliation(s)
- János Juhász
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary.,3in-PPCU Research Group, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Esztergom, Hungary
| | - Zoltán Gáspári
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Sándor Pongor
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
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