Showing papers on "Protoporphyrins published in 1963"

Studies on the biosynthesis of porphyrin and bacteriochlorophyll by Rhodopseudomonas spheroides. 4. S-Adenosylmethionine–magnesium protoporphyrin methyltransferase

Abstract: Gibson, Neuberger & Tait (1962b) have shown that ethionine inhibits the biosynthesis of bacteriochlorophyll and stimulates the excretion of coproporphyrin by illuminated suspensions of Rhodopseudomonas spheroides, and that this effect can be reversed by methionine. It was suggested that methionine might be concerned in a specific manner in the formation of bacteriochlorophyll, and evidence was presented to show that the methyl group of methionine is a direct precursor of the methyl ester group of bacteriochlorophyll. Tait & Gibson (1961) reported that chromatophores from Rps. spheroides catalyse the transfer of the methyl group of S-adenosylmethionine to magnesium protoporphyrin to form a compound that was tentatively identified as magnesium protoporphyrin monomethyl ester. The present paper describes the further characterization of the enzyme, S-adenosylmethionine-magnesium protoporphyrin methyltransferase, and the identification of the product formed.