ISSN:
1432-1327
Keywords:
Key words Cytochrome c4
;
Resonance Raman
;
Heme-protein interactions
;
"Core" expansion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract Di-heme Pseudomonas stutzeri cytochrome c 4 has been characterized by electronic absorption and resonance Raman spectroscopies in the ferric and ferrous forms at pH 7.5 and at room temperature. The data indicate that the two hemes are inequivalent. It is proposed that the N-terminal contains a more relaxed heme as a consequence of the relative orientation of the methionine and histidine ligands with respect to the N-Fe-N directions of the heme plane. This causes a weakening of the Fe-S bond with concomitant partial dissociation of the methionine and the formation of an Fe-aquo bond. Heme group relaxation is further accompanied by less distortion of the heme group than that associated with cytochrome c, expansion of the "core" and a negative shift of the redox potential.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s007750050136
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