Enzymes catalyzing the de novo synthesis of methyl groups in the brain and other tissues of the rat.

摘要: —Rat brain contains all three of the enzymes required for de novo synthesis methyl group methionine (serine transhydroxymethylase, methylene reductase, and [B12]transmethylase) in activities comparable to those found liver kidney. The reductase female kidney, [B12]transmethylase are higher than corresponding male tissues. Liver kidney extracts contain an inhibitor not present extracts. This differs from S-adenosylmethionine (SAM), which also inhibits both homogenates. administration l-DOPA rats, has been previously shown deplete S-adenosylmethionine, reduces activity if assayed without added SAM. Since SAM is this enzyme, its decreased probably results decline concentration. De now groups could be a mechanism by maintains level face increased utilization after l-DOPA.