Resumen

TRAVIESO GONZALEZ, Yelamy; MUSTELIER ZAMORA, Pavel; MARTINEZ BENITEZ, Zonia  y  POSADA GARCIA, Aimé. Relevant aspects of S-adenosylhomocysteine hydrolase related to the metabolism of S-adenosylhomocysteine. Rev Cubana Invest Bioméd [online]. 2006, vol.25, n.2. ISSN 0864-0300.

A review of S-adenosylmethionine, considered as the fundamental donor of methyl groups in the organism, was made. S-adenosylhomocysteine, which is a powerful inhibitor of transmethylases depending on S-adenosylmethionine, is obtained by a  transmethylation reaction. The inhibition of the reactions of transmethylation depending on  SAM, is revealed by the metabolic conversion of  S-adenosylhomocysteine into adenosine and L-homocysteine by a reversible reaction catalyzed by S-adenosylhomocysteine hydrolase. This enzyme is present in the liver, pancreas, and kidney. It is composed of two a  and two b chains, which are joined by four disulphure bonds.  It also has sulphidril residuals. The enzyme is regulated by its substrates, adenosine, L-homocysteine, in vitro purines and other metabolites. The S-adenosylhomocysteine hydrolase is irreversibly inhibited by 5-desoi-5-difluoromethyl tioadenosine and 5-deoxy-5-trifluoromethyl tioadenosine.

Palabras clave : S-adenosylmethionine; S-adenosylhomocysteine; L-homocysteine; adenosine.

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