Kinetic studies on the oxidation of cytochrome b(5) Phe35 mutants with cytochrome c, plastocyanin and inorganic complexes.
To illustrate the functions of the aromatic residue Phe35 of cytochrome b(5) and to give further insight into the roles of the Phe35-containing hydrophobic patch and/or aromatic channel of cytochrome b(5), we studied electron transfer reactions of cytochrome b(5) and its Phe35Tyr and Phe35Leu variants with cytochrome c, with the wild-type and Tyr83Phe and Tyr83Leu variants of plastocyanin, and with the inorganic complexes [Fe(EDTA)](-), [Fe(CDTA)](-) and [Ru(NH(3))(6)](3+). The changes at Phe35 of cytochrome b(5) and Tyr83 of plastocyanin do not affect the second-order rate constants for the electron transfer reactions. These results show that the invariant aromatic residues and aromatic patch/channel are not essential for electron transfer in these systems.
Yao
Ping
P
Chemical Biology Laboratory, Department of Chemistry, Fudan University, Shanghai 200433, China.
Wang
Yun-Hua
YH
Sun
Bing-Yun
BY
Xie
Yi
Y
Hirota
Shun
S
Yamauchi
Osamu
O
Huang
Zhong-Xian
ZX
D003574:Cytochrome c Group / Q000378:metabolism*; D015786:Cytochromes b5 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004492:Edetic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D004579:Electron Transport; D007287:Inorganic Chemicals / Q000737:chemistry / Q000378:metabolism; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D007930:Leucine / Q000235:genetics; D009154:Mutation; D010084:Oxidation-Reduction; D010649:Phenylalanine / Q000235:genetics; D010970:Plastocyanin / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet; D014443:Tyrosine / Q000235:genetics
D003574:Cytochrome c Group; D007287:Inorganic Chemicals; D014443:Tyrosine; D010649:Phenylalanine; C005390:CDTA; D010970:Plastocyanin; D015786:Cytochromes b5; D004492:Edetic Acid; D007501:Iron; D007930:Leucine