An -Helical Burst in the src SH3 Folding Pathway
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- 作者：Jinsong Li ; Masaji Shinjo ; Yoshitaka Matsumura ; Masayuki Morita ; David Baker ; Masamichi Ikeguchi ; Hiroshi Kihara
- 刊名：Biochemistry
- 出版年：2007
- 出版时间：May 1, 2007
- 年：2007
- 卷：46
- 期：17
- 页码：5072 - 5082
- 全文大小：369K
- 年卷期：v.46,no.17(May 1, 2007)
- ISSN：1520-4995
文摘
Src SH3 is a small all-
-sheet protein composed of a single domain. We studied the foldingbehavior of src SH3 at various conditions by circular dichroism (CD), fluorescence, and X-ray solutionscattering methods. On the src SH3 folding pathway, an 
-helix-rich intermediate appeared not only atsubzero temperatures but also above 0 
C. The fraction of -helix in the kinetically observed intermediateis ca. 26% based on the kinetic CD experiment. X-ray solution scattering revealed that the intermediatewas compact but not fully packed. The analysis of CD implies that the amplitude of the burst phase isproportional to the helical fraction calculated according to the helix-coil transition theory. This stronglysuggests that the initial folding core is formed by the collapse of much less stably existing -helices.
-sheet protein composed of a single domain. We studied the foldingbehavior of src SH3 at various conditions by circular dichroism (CD), fluorescence, and X-ray solutionscattering methods. On the src SH3 folding pathway, an -helix-rich intermediate appeared not only atsubzero temperatures but also above 0 C. The fraction of -helix in the kinetically observed intermediateis ca. 26% based on the kinetic CD experiment. X-ray solution scattering revealed that the intermediatewas compact but not fully packed. The analysis of CD implies that the amplitude of the burst phase isproportional to the helical fraction calculated according to the helix-coil transition theory. This stronglysuggests that the initial folding core is formed by the collapse of much less stably existing -helices.