期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2007
卷号：104
期号：44
页码：17329-17334
DOI：10.1073/pnas.0705417104
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Most proteins are in equilibrium with partially and globally unfolded conformations. In contrast, kinetically stable proteins (KSPs) are trapped by an energy barrier in a specific state, unable to transiently sample other conformations. Among many potential roles, it appears that kinetic stability (KS) is a feature used by nature to allow proteins to maintain activity under harsh conditions and to preserve the structure of proteins that are prone to misfolding. The biological and pathological significance of KS remains poorly understood because of the lack of simple experimental methods to identify this property and its infrequent occurrence in proteins. Based on our previous correlation between KS and a protein's resistance to the denaturing detergent SDS, we show here the application of a diagonal 2D (D2D) SDS/PAGE assay to identify KSPs in complex mixtures. We applied this method to the lysate of Escherichia coli and upon proteomics analysis have identified 50 nonredundant proteins that were SDS-resistant (i.e., kinetically stable). Structural and functional analyses of a subset (44) of these proteins with known 3D structure revealed some potential structural and functional biases toward and against KS. This simple D2D SDS/PAGE assay will allow the widespread investigation of KS, including the proteomics-level identification of KSPs in different systems, potentially leading to a better understanding of the biological and pathological significance of this intriguing property of proteins.
