title: Complex formation between flavodoxin and cytochrome c. Cross-linking studies.
abstract: Complex formation between Azotobacter vinelandii flavodoxin and horse cytochrome c has been demonstrated through cross-linking studies with dimethyl suberimidate, dimethyl adipimidate, 1-ethyl-3-(3-di-methylaminopropyl)carbodiimide, and dimethyl-3,3'-dithiobispropionimidate. Essentially quantitative cross-linking of cytochrome c and flavodoxin was observed at low ionic strengths with the carbodiimide cross-linking reagent. An association constant of 4 X 10(4) M-1 was obtained between cytochrome c and flavodoxin at 88 mM ionic strength from analysis of the cross-linking studies. This value is similar to the association constant determined kinetically during the electron transfer reaction between cytochrome c and flavodoxin (Simondsen, R.P., Weber, P.C., Salemme, F.R., and Tollin, G. (1982) Biochemistry 21, 6366-6375), and suggests that the cross-linked complex may be similar to the precursor complex identified kinetically. A structural model for the flavodoxin-cytochrome c complex proposed by these workers is shown to be compatible with the present cross-linking results.
authors.forename: J L
authors.initials: JL
authors.lastname: Dickerson
authors.forename: J J
authors.initials: JJ
authors.lastname: Kornuc
authors.forename: D C
authors.initials: DC
authors.lastname: Rees
mesh_terms: D001395:Azotobacter; D003574:Cytochrome c Group / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005418:Flavodoxin / Q000378:metabolism*; D005420:Flavoproteins / Q000378:metabolism*; D008433:Mathematics; D009994:Osmolar Concentration; D011487:Protein Conformation
chemical_list: D003574:Cytochrome c Group; D005418:Flavodoxin; D005420:Flavoproteins