Open AccessIdentification of membrane‐bound c ‐type cytochromes in an acidophilic ferrous ion oxidizing bacterium Thiobacillus ferrooxidans
Author(s) -
Elbehti Amina,
LemesleMeunier Danielle
Publication year - 1996
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1996.tb08024.x
Subject(s) - cytochrome , thiobacillus , cytochrome c , biochemistry , ferrous , hemeprotein , heme , molecular mass , bacteria , amino acid , chemistry , biology , enzyme , mitochondrion , organic chemistry , genetics
Three membrane‐bound acid‐stable cytochromes c with molecular masses of 46, 30 and 21 kDa were characterized from a new Thiobacillus ferrooxidans strain. They were solubilized with high concentrations of dodecylmaltoside at pH 8. The 30 kDa cytochrome c was purified to a homogeneous state as established by SDS‐PAGE analysis. It showed an absorption peak at 410 nm in the oxidized form and at 418, 523 and 552 nm in the reduced form. The 46 kDa cytochrome c co‐purified with a non‐heme protein of 36 kDa. The amino acid composition and the N‐terminal amino acid sequence of the 46 kDa cytochrome c were determined and compared with those of the soluble 14 kDa and the membrane‐bound 21, 22.3 and 68 kDa cytochromes c isolated from two different strains. The results clearly show that this cytochrome is distinct from both the 22.3, 21 and 14 kDa cytochrome species, and exhibits some similarities with the 68 kDa cytochrome c as regards its amino acid composition.