Evaluation of cytochrome c affinity to anionic phospholipids by means of surface plasmon resonance.
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.
Stepanov
German
G
Department of Medical Biophysics, Russian State Medical University, Moscow, Russia.
Gnedenko
Oksana
O
Mol'nar
Andrey
A
Ivanov
Alexis
A
Vladimirov
Yuri
Y
Osipov
Anatoly
A
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
D000838:Anions; D002308:Cardiolipins; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines; D010718:Phosphatidylserines; D010743:Phospholipids; D045304:Cytochromes c; D009195:Peroxidase