Phospholipid–cytochrome c interactions
نویسندگان
چکیده
9 REVIEW OF THE LITERATURE 11 Structure of cytochrome c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Phospholipid binding by cyt c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Cyt c in apoptosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 ATP binding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Zinc-heme cyt c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Amyloid fibers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 AIMS OF THE STUDY 23 MATERIALS AND METHODS 24 Reagents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Cyt c solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Preparation of the [Zn2+-heme] cyt c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Fluorescence spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 90-degree light scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Preparation of liposomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Circular dichroism spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Brominated lipids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Fiber formation and imaging of the fibers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 RESULTS 29 The invariant Arg91 is required for the aggregation of liposomes by cyt c (I) . . . . . . . . 29 ATP binding induces a conformational change in C-site lipid–bound cyt c (II) . . . . . 30 Extended lipid anchorage (III) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Fibrous cyt c–phospholipid aggregates (IV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
منابع مشابه
The indispensability of phospholipid and ubiquinone in mitochondrial electron transfer from succinate to cytochrome c.
The indispensability of phospholipid and ubiquinone (Q) in mitochondrial electron transfer was studied by depleting phospholipid and Q in succinate-cytochrome c reductase and then replenishing the depleted enzyme. More than 90% of phospholipid and Q was removed by repeated ammonium sulfate-cholate fractionation. The depleted succinate-cytochrome c reductase showed no enzymatic activity for succ...
متن کاملIonic-strength-dependence of the oxidation of native and pyridoxal 5'-phosphate-modified cytochromes c by cytochrome c oxidase.
The ionic-strength-dependences of the rate constants (log k plotted versus square root of 1) for oxidation of native and pyridoxal 5'-phosphate-modified cytochromes c by three different preparations of cytochrome c oxidase have complex non-linear character, which may be explained on the basis of present knowledge of the structure of the oxidase and the monomer-dimer equilibrium of the enzyme. T...
متن کاملImpact of nonspecific binding to microsomes and phospholipid on the inhibition of cytochrome P4502D6: implications for relating in vitro inhibition data to in vivo drug interactions.
The effects of microsomal concentration on the inhibitory potencies of four compounds--fluoxetine, quinidine, imipramine, and ezlopitant--on heterologously expressed recombinant CYP2D6-catalyzed bufuralol 1'-hydroxylase activity were determined. Increasing microsomal concentration from 0.0088 to 2.0 mg/ml, using additional microsomes not containing cytochrome P450, resulted in a marked increase...
متن کاملA cytochrome c-phospholipid complex.
Lipids may play an important role in the maintenance of proper spatial configuration between the various members of the mitochondrial electron transport chain (1, 2). Greenlees and Wainio (3) and Hatefi (4) have shown that phospholipids are essential for the activity of cytochrome c oxidase. In its present state of purity, thii enzyme contains approximately 15% phospholipid and may exist as a l...
متن کاملInteractions of phospholipase D and cytochrome P450 protein stability.
Previous studies have suggested a relationship between cytochrome P450 (P450) 3A (CYP3A) conformation and the phospholipid composition of the associated membrane. In this study, we utilized a novel microsomal incubation system that mimics many of the characteristics of CYP3A degradation pathway that have been observed in vivo and in cultured cells to study the effects of phospholipid compositio...
متن کامل