title: Thermal stability of the polyheme cytochrome c3 superfamily.
abstract: The cytochrome c3 superfamily includes Desulfovibrio polyheme cytochromes c. We report the characteristic thermal stability parameters of the Desulfovibrio desulfuricans Norway (D.d.N.) cytochromes c3 (M(r) 13,000 and M(r) 26,000) and the Desulfovibrio vulgaris Hildenborough (D.v.H.) cytochrome c3 (M(r) 13,000) and high molecular mass cytochrome c (Hmc), as obtained with the help of electronic spectroscopy, voltammetric techniques and differential scanning calorimetry. The polyheme cytochromes are denatured over a wide range of temperatures: the D.v.H. cytochrome c3 is highly thermostable (Td = 121 degrees C) contrary to the D.d.N. protein (Td = 73 degrees C). The thermostability of the polyheme cytochromes is redox state dependent. The results are discussed in the light of the structural and functional relationships within the cytochrome c3 superfamily.
authors.affiliation: Unité de Bioénergétique et Ingénierie des Protéines, C.N.R.S. 31, Marseilles, France.
authors.forename: L
authors.initials: L
authors.lastname: Florens
authors.forename: P
authors.initials: P
authors.lastname: Bianco
authors.forename: J
authors.initials: J
authors.lastname: Haladjian
authors.forename: M
authors.initials: M
authors.lastname: Bruschi
authors.forename: I
authors.initials: I
authors.lastname: Protasevich
authors.forename: A
authors.initials: A
authors.lastname: Makarov
mesh_terms: D002152:Calorimetry, Differential Scanning; D003574:Cytochrome c Group / Q000737:chemistry / Q000378:metabolism*; D003901:Desulfovibrio / Q000737:chemistry*; D006418:Heme / Q000378:metabolism; D010084:Oxidation-Reduction; D011489:Protein Denaturation; D013057:Spectrum Analysis; D013696:Temperature; D013816:Thermodynamics
chemical_list: D003574:Cytochrome c Group; D006418:Heme; C017165:cytochrome c(3)