PROTON NUCLEAR-MAGNETIC-RESONANCE AS A PROBE OF DIFFERENCES IN STRUCTURE BETWEEN THE C102T AND F82S,C102T VARIANTS OF ISO-1-CYTOCHROME-C FROM THE YEAST SACCHAROMYCES-CEREVISIAE

被引:30
作者
GAO, Y
BOYD, J
PIELAK, GJ
WILLIAMS, RJP
机构
[1] UNIV N CAROLINA, DEPT CHEM, CHAPEL HILL, NC 27599 USA
[2] UNIV N CAROLINA, PROGRAM MOLEC BIOL & BIOTECHNOL, CHAPEL HILL, NC 27599 USA
[3] UNIV OXFORD, INORGAN CHEM LAB, OXFORD OX1 3QR, ENGLAND
[4] UNIV OXFORD, DEPT BIOCHEM, OXFORD OX1 3QU, ENGLAND
关键词
D O I
10.1021/bi00242a032
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Differences in chemical shifts and in nuclear Overhauser effects between the C102T and F82S,C102T variants of Saccharomyces cerevisiae iso-1-cytochrome c in both the reduced and oxidized forms are reported and analyzed. There is evidence for small conformational differences in both oxidation states of the double variant near position 82. Differences in structure are more evident in the oxidized forms of the variants. These differences extend to distant parts of the protein. It is concluded that the oxidized double variant has undergone a small rearrangement of several regions of the protein that are linked by a hydrogen-bond network. It is shown that the rearrangement involves hydrogen bonds associated with the two heme propionates and associated water molecules. The deductions from nuclear magnetic resonance data are compared with the differences in the crystal structures of the reduced forms of wild-type protein and the F82S variant [Louie, G. V., Pielak, G. J., Smith, M., & Brayer, G. D. (1988) Biochemistry 27, 7870-7876].
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页码:7033 / 7040
页数:8
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