Conclusions
None of the synthetic analogues ofS-adenosyl-l-homocysteine was a more potent inhibitor of the enzyme thanS-adenosyl-l-homocysteine itself. Several requirements very probably had to be fulfilled for inhibition of gastric histamine methyltransferase by compounds similar in structure to S-adenosyl-l-homocysteine: (1) The side chain linked to the 5′-position of ribose must bear an amino acid residue; (2) the chain-length of this residue must be the same as that of homocysteine; (3) the heterocyclic base has to be a purine base with a nucleophilic center at position 6; (4) this nucleophilic center must not be sterically hindered by substitutes; (5) the purine base must have a nitrogen atom in position 3. These requirements indicate, that the binding sites, proposed byZappia et al. [2] for various methyltransferases were identical with those found for the fixation ofS-adenosyl-l-homocysteine or its analogues to histamine methyltransferase.
Similar content being viewed by others
References
M. Baudry, F. Chast andJ.-C. Schwartz, J. Neurochem.20, 13–21 (1973).
V. Zappia, C. R. Zydeck-Cwick andF. Schlenk, J. Biol. Chem.244, 4499–4509 (1969).
T. Deguchi andJ. Barchas, J. Biol. Chem.246, 3175–3181 (1971).
P. Ball, R. Knuppen, M. Haupt andH. Breuer, Eur. J. Biochem.26, 560–569 (1972).
J. K. Coward, M. D'urso-Scott andW. D. Sweet, Biochem. Pharmac.21, 1200–1203 (1972).
S. J. Kerr, J. Biol. Chem.247, 4248–4252 (1972).
J. Hildesheim, R. Hildesheim andE. Lederer, Biochimie (Paris)53, 1067–1071 (1971).
J. Hildesheim, R. Hildesheim andE. Lederer, Biochimie (Paris)54, 431–437 (1972).
H. Barth, I. Niemeyer andW. Lorenz, Agents and Actions3, 138–147 (1973).
S. H. Snyder andJ. Axelrod, Biochim. Biophys. Acta111, 416–421 (1965).
H. Barth, W. Lorenz andI. Niemeyer, Hoppe-Seyler's Z. physiol. Chem.354, 1021–1026 (1973).
H. Barth, I. Niemeyer andW. Lorenz, Agents and Actions3, 173–175 (1973).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Barth, H., Niemeyer, I. & Lorenz, W. Speculations about the binding sites of S-adenosyl-l-homocysteine and some of its synthetic analogues to histamine methyltransferase. Agents and Actions 4, 186–188 (1974). https://doi.org/10.1007/BF01970266
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01970266