Simplified isolation and molecular composition of NADH dehydrogenase of the respiratory chain.

摘要: A simplified procedure for the isolation of NADH dehydrogenase from inner membrane ox heart mitochondria is presented which permits relatively rapid preparation enzyme in a more stable form than that afforded by published methods. The protein thus isolated displays eight different subunits gel electrophoresis under denaturing conditions, three are also present "low-molecular-weight form' prepared drastic conditions. Complex I contains several subunits, mostly low molecular weight, not seen soluble purified dehydrogenase. It suggested some these may be 'binding peptides' necessary linking to ubiquinone reduction, analogously role small peptides succinate ubiquinone. method equimolar amounts non-haem iron and labile sulphur, but on further manipulation (but no sulphur) lost, resulting ratios S/Fe excess unity, as previously reported preparations longer procedures.