Functional Characterization of an Unknown Soybean Intrinsically Disordered Protein in Vitro and in Escherichia coli
Intrinsically disordered protein, Cytoprotection, Freeze-thaw cycles, Heat stable, Secondary structure
Digital Object Identifier (DOI)
Intrinsically disordered proteins (IDPs) possess a wide range of biological function in all organisms, however the specific functions of most IDPs are still unknown. Soybean LOC protein, LOC for short, is a heat-stable protein, which is more abundant in the stress-resistant radicles. Sequence alignment and phylogenetic analysis showed that LOC is a functionally unknown protein and conserved in Fabaceae. LOC, being enriched in most disorder-promoting residues and depleted in most order-promoting residues, was predicted to contain high levels of intrinsic disorder by several commonly used computational tools. However, it was also predicted to contain two disorder-based protein-protein binding sites and two short α-helical segments. The circular dichroism spectroscopic analysis showed that this protein is mostly disordered in water, but can form more α-helical structure in the presence of SDS and TFE. Functional in vitro studies showed that the LOC protein is able to prevent lactate dehydrogenase inactivation by freeze-thaw at a molar ratio of 10:1. Furthermore, in vivo analyses revealed the survival rate of Escherichia coli over-expressing LOC protein under the conditions of osmotic stress was noticeably increased in comparison with the control. These observations suggest that the intrinsically disordered protein LOC might serve as a chaperone and/or cell protector.
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Citation / Publisher Attribution
International Journal of Biological Macromolecules, v. 166, p. 538-549
Scholar Commons Citation
Tan, Fangmei; Sun, Nan; Zhang, Linsong; Wu, Jiahui; Xiao, Shifeng; Tan, Qiulong; Uversky, Vladimir N.; and Liu, Yun, "Functional Characterization of an Unknown Soybean Intrinsically Disordered Protein in Vitro and in Escherichia coli" (2021). Molecular Medicine Faculty Publications. 207.