Thermal stability of cytochrome c' from mesophilic Shewanella amazonensis.
Cytochrome c' (SACP) from mesophilic Shewanella amazonensis, growing optimally at 37 °C, was thermally more stable than cytochrome c' (AVCP) from mesophilic Allochromatium vinosum, growing optimally at 25 °C. In contrast, SACP was less stable than cytochrome c' (PHCP) from thermophilic Hydrogenophilus thermoluteolus, growing optimally at 52 °C. Although only 28% of the SACP amino acid sequence was identical to those of AVCP and PHCP, the latter two being 55% identical, the overall main chain structures of the three cytochromes c' were similar, and SACP exhibited thermal stability intermediate between those of AVCP and PHCP. For these three proteins, the higher the stability is, the lesser the number of Gly residues in the putative α-helical regions is. Cytochromes c' including the present three are suitable for examining the protein stabilization mechanisms, because they are structurally similar and available from environments with a wide range of temperatures.
a Graduate School of Biosphere Science , Hiroshima University , Higashi-Hiroshima , Japan.
Yuki
Y
Kato
Sotaro
S
Fujii
Taka-aki
TA
Kuribayashi
Misa
M
Masanari
Yoshihiro
Y
Sambongi
D000595:Amino Acid Sequence; D002841:Chromatiaceae / Q000201:enzymology; D002942:Circular Dichroism; D045304:Cytochromes c / Q000737:chemistry* / Q000378:metabolism; D004795:Enzyme Stability; D043363:Hydrogenophilaceae / Q000201:enzymology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011489:Protein Denaturation; D017386:Sequence Homology, Amino Acid; D020592:Shewanella / Q000201:enzymology* / Q000254:growth & development; D013696:Temperature; D013816:Thermodynamics
D045304:Cytochromes c
Shewanella amazonensis; circular dichroism; cytochrome c′; thermal stability