A mass spectrometry study on the topology of Cytochrome P450 17(alpha)-Cytochrome b_5 complex by using crosslinker

摘要

Cytochrome P450s in endoplasmic reticulum membranes function in the hydroxylation of exogenous and endogenous hydrophobic substrates concentrated in the membranes. The reactions require two electrons supplied by redox partners. P450 17(alpha) (CYP17) receives the first electron from NADPH-cytochrome P450 reductase directly. Cytochrome b_5 (Cytb5) also plays a role of metabolic reactions of CYP17. However, the mechanism of second electron transfer is inapparent. To elucidate the metabolic mechanism of CYP17, we have investigated the membrane topology of CYP17 and also protein-protein interactions of CYP17-Cytochrome b_5 (Cytb5) complex by using cross-linking and mass spectrometry.