Oxidation of residue 45 mutant forms of pig deoxymyoglobin with [Fe(CN)6]3-.
The effect of replacement of the highly conserved Lys45 residue in pig myoglobin (Mb) with His, Ser, Glu, and Arg has been investigated. Rate constants/M-1 s-1 at 25 degrees C and pH 8.0, I = 0.100 M (NaCl), for the oxidation of deoxyMb with [Fe(CN)6]3- have been determined, and are for wild-type Lys45 (2.83 x 10(6)), His45 (1.02 x 10(6)), Ser45 (1.12 x 10(6)), Glu45 (0.87 x 10(6)), and Arg45 (3.06 x 10(6)). It is concluded that charge on the residue at position 45 has only a mild effect on reactivity, and that this is unlikely to be the site for electron transfer.
Zhang
B J
BJ
Department of Chemistry, The University, Newcastle upon Tyne, U.K.
Smerdon
S J
SJ
Wilkinson
A J
AJ
Sykes
A G
AG
D000818:Animals; D004563:Electrochemistry; D005292:Ferricyanides / Q000378:metabolism*; D007700:Kinetics; D008239:Lysine / Q000378:metabolism; D015394:Molecular Structure; D016296:Mutagenesis; D009211:Myoglobin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction; D013329:Structure-Activity Relationship; D013552:Swine
D005292:Ferricyanides; D009211:Myoglobin; C055547:deoxymyoglobin; D008239:Lysine; C028033:potassium ferricyanide