S-adenosyl-L-methionine:magnesium-protoporphyrin IX O-methyltransferase from Rhodobacter capsulatus: mechanistic insights and stimulation with phospholipids.

ABSTRACT: The enzyme BchM (S-adenosyl-L-methionine:magnesium-protoporphyrin IX O-methyltransferase) from Rhodobacter capsulatus catalyses an intermediate reaction in the bacteriochlorophyll biosynthetic pathway. Overexpression of His(6)-tagged protein in Escherichia coli resulted in the majority of polypeptide existing as inclusion bodies. Purification from inclusion bodies was performed using metal-affinity chromatography after an elaborate wash step involving surfactant polysorbate-20. Initial enzymatic assays involved an in situ generation of S-adenosyl-L-methionine substrate using a crude preparation of S-adenosyl-L-methionine synthetase and this resulted in higher enzymatic activity compared with commercial S-adenosyl-L-methionine. A heat-stable stimulatory component present in the S-adenosyl-L

SUBMITTER: Sawicki A 

PROVIDER: S-EPMC2049041 | biostudies-literature | 2007 Sep

REPOSITORIES: biostudies-literature