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Mechanism of kinase inactivation and nonbinding of fratide to GSK3β due to K85M mutation: Molecular dynamics simulation and normal mode analysis
Author(s) -
Lu ShaoYong,
Jiang YongJun,
Lv Jing,
Zou JianWei,
Wu TianXing
Publication year - 2011
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.21629
Subject(s) - chemistry , mechanism (biology) , molecular dynamics , mode (computer interface) , dynamics (music) , mutation , biophysics , computational chemistry , biochemistry , gene , psychology , physics , quantum mechanics , biology , pedagogy , computer science , operating system
As a serine/threonine protein kinase, glycogen synthase kinase 3β (GSK3β) is an essential component of several cellular processes, including insulin, growth factor, and Wnt signaling. The conserved K85 is important to GSK3β activity and FRATide binding. To elucidate the mechanisms concerning kinase inactivation and nonbinding of FRATide to GSK3β, molecular dynamics (MD) simulation, molecular mechanics generalized Born/surface area (MM_GBSA) calculation, and normal mode analysis (NMA) were performed on both the wild‐type (WT) and the K85M mutation of the GSK3β‐FRATide complex. The results revealed that the periodic open‐closed conformational change of the G loop, together with the compact conformation of the RD pocket, was disturbed in the K85M mutant, in contrast to those in the WT. This in turn caused inhibition of GSK3β. Specifically, the correct folding pattern of GSK3β was disrupted in the K85M mutant, resulting in the loss of two key hydrogen bonds between K214 of FRATide and E290 and K292 of GSK3β, respectively. Furthermore, MM_GBSA calculations indicated that the K85M mutation could lead to a less energy‐favorable GSK3β‐FRATide complex. In addition, NMA demonstrated that the “rocking” of the N‐ and C‐terminal domains of GSK3β, which coordinates the mutual movement of both lobes, inducing the opening and closing of the active site of GSK3β, which may assist the entry of ATP into the ATP binding site and the release of the ADP product. Strikingly, this phenomenon was not clearly observed in the K85M mutation. This study provides a structural basis for the effect of the K85M mutation on the GSK3β‐FRATide complex. © 2011 Wiley Periodicals, Inc. Biopolymers 95: 669–;681, 2011.