کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2188452 1096169 2007 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Optimized Variants of the Cold Shock Protein from in Vitro Selection: Structural Basis of Their High Thermostability
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Optimized Variants of the Cold Shock Protein from in Vitro Selection: Structural Basis of Their High Thermostability
چکیده انگلیسی

The bacterial cold shock proteins (Csp) are widely used as models for the experimental and computational analysis of protein stability. In a previous study, in vitro evolution was employed to identify strongly stabilizing mutations in Bs-CspB from Bacillus subtilis. The best variant found by this approach contained the mutations M1R, E3K and K65I, which raised the midpoint of thermal unfolding of Bs-CspB from 53.8 °C to 83.7 °C, and increased the Gibbs free energy of stabilization by 20.9 kJ mol−1. Another selected variant with the two mutations A46K and S48R was stabilized by 11.1 kJ mol−1. To elucidate the molecular basis of these stabilizations, we determined the crystal structures of these two Bs-CspB variants. The mutated residues are generally well ordered and provide additional stabilizing interactions, such as charge interactions, additional hydrogen bonds and improved side-chain packing. Several mutations improve the electrostatic interactions, either by the removal of unfavorable charges (E3K) or by compensating their destabilizing interactions (A46K, S48R). The stabilizing mutations are clustered at a contiguous surface area of Bs-CspB, which apparently is critically important for the stability of the β-barrel structure but not well optimized in the wild-type protein.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Biology - Volume 369, Issue 4, 15 June 2007, Pages 1087–1097
نویسندگان
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