title: Evaluation of cytochrome c affinity to anionic phospholipids by means of surface plasmon resonance.
abstract: We attempted to evaluate the affinity of the anionic phospholipids to cytochrome c by means of surface plasmon resonance (SPR) technique and to correlate it with the cytochrome c active site alterations and peroxidase activity. Our experiments showed a strong interdependence between the phospholipid fatty acid saturation degree, the active site structure alterations and peroxidase activity of the cytochrome c phospholipid complex. Cytochrome c peroxidase activity and Trp59 fluorescence increase in the sequence of phosphatidyl choline (PC)-->phosphatidylserine (PS)-->cardiolipin (CL)-->phosphatidic acid (PA). The association constant (K(a)) increased in the sequence PC-->PA-->PS-->CL. The SPR spectroscopy data shows that K(a) is independent of lipid saturation degree, but correlates with phospholipid negative charge value.
authors.affiliation: Department of Medical Biophysics, Russian State Medical University, Moscow, Russia.
authors.forename: German
authors.initials: G
authors.lastname: Stepanov
authors.forename: Oksana
authors.initials: O
authors.lastname: Gnedenko
authors.forename: Andrey
authors.initials: A
authors.lastname: Mol'nar
authors.forename: Alexis
authors.initials: A
authors.lastname: Ivanov
authors.forename: Yuri
authors.initials: Y
authors.lastname: Vladimirov
authors.forename: Anatoly
authors.initials: A
authors.lastname: Osipov
mesh_terms: D000838:Anions / Q000737:chemistry; D002308:Cardiolipins / Q000737:chemistry; D020134:Catalytic Domain; D045304:Cytochromes c / Q000737:chemistry*; D009994:Osmolar Concentration; D009195:Peroxidase / Q000737:chemistry; D010712:Phosphatidic Acids / Q000737:chemistry; D010713:Phosphatidylcholines / Q000737:chemistry; D010718:Phosphatidylserines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D000838:Anions; D002308:Cardiolipins; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines; D010718:Phosphatidylserines; D010743:Phospholipids; D045304:Cytochromes c; D009195:Peroxidase