Stability enhancement of cytochrome c through heme deprotonation and mutations.


Abstract

The chemical denaturation of Pseudomonas aeruginosa cytochrome c(551) variants was examined at pH 5.0 and 3.6. All variants were stabilized at both pHs compared with the wild-type. Remarkably, the variants carrying the F34Y and/or E43Y mutations were more stabilized than those having the F7A/V13M or V78I ones at pH 5.0 compared with at pH 3.6 by ~3.0-4.6 kJ/mol. Structural analyses predicted that the side chains of introduced Tyr-34 and Tyr-43 become hydrogen donors for the hydrogen bond formation with heme 17-propionate at pH 5.0, but less efficiently at pH 3.6, because the propionate is deprotonated at the higher pH. Our results provide an insight into a stabilization strategy for heme proteins involving variation of the heme electronic state and introduction of appropriate mutations. Study holds ProTherm entries: 24920, 24921, 24922, 24923, 24924, 24925, 24926, 24927, 24928, 24929, 24930, 24931, 24932, 24933, 24934, 24935, 24936, 24937, 24938, 24939 Extra Details: Circular dichroism spectroscopy; Cytochrome c; Hydrogen bond; Protein stability; Heme propionate

Submission Details

ID: FB65dEC54

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:55 p.m.

Version: 1

Publication Details
Sonoyama T;Hasegawa J;Uchiyama S;Nakamura S;Kobayashi Y;Sambongi Y,Biophys. Chem. (2009) Stability enhancement of cytochrome c through heme deprotonation and mutations. PMID:18957274
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