Open AccessEffects of the Tyr64 Substitution on the Stability of Cytochrome c 553 , a low Oxidoreduction‐Potential Cytochrome from Desulfovibrio vulgaris Hildenborough
Author(s) -
Blanchard Laurence,
Dolla Alain,
Bersch Beate,
Forest Eric,
Bianco Pierre,
Wall Judy,
Marion Dominique,
Guerlesquin Françoise
Publication year - 1994
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1994.tb20067.x
Subject(s) - desulfovibrio vulgaris , cytochrome , chemistry , heme , cytochrome c , mutant , cytochrome b , hemeprotein , biochemistry , desulfovibrio , stereochemistry , sulfate , bacteria , enzyme , mitochondrion , organic chemistry , biology , mitochondrial dna , genetics , gene
Cytochrome c 553 from sulfate‐reducing bacteria is a lowoxidoreduction‐potential cytochrome. The primary and tertiary structures show notable differences when compared to mitochondrial cytochromes. Tyr64 replacement in cytochrome c 553 provides evidence that this residue is not directly involved in the potential modulation but is mostly implicated in the hydrogenbond network around the heme. While the different variants obtained did not induce drastic structural modifications, they did affect the stability of the protein. This decrease of stability in acidic and alkaline environments was observed by variations in the optical spectra and by mass spectrometry. In addition, the mobility of aromatic side‐chain was found to be increased in the mutant proteins as monitored by two‐dimensional NMR spectroscopy.