TY - JOUR T1 - Heterogeneity of <em>N</em>- and <em>O</em>-Methyltransferases JF - Molecular Pharmacology JO - Mol Pharmacol SP - 78 LP - 84 VL - 6 IS - 1 AU - JULIUS AXELROD AU - ELLIOT S. VESELL Y1 - 1970/01/01 UR - http://molpharm.aspetjournals.org/content/6/1/78.abstract N2 - The methyltransferases phenylethanolamine N-methyltransferase, histamine N-methyltransferase (EC 2.1.1.8), catechol O-methyltransferase (EC 2.1.1.6), and hydroxyindole O-methyltransferase, from tissues of several species, were subjected to starch block electrophoresis. Adrenal phenylethanolamine N-methyltransferase and pineal hydroxyindole O-methyltransferase were heterogeneous among different species with respect to electrophoretic mobility on starch block, heat stability, and substrate specificity, but they were homogeneous within a given species. Multiple forms of histamine N-methyltransferase and catechol O-methyltransferase occurred in tissues within a given species as well as among different species. They had different electrophoretic mobilities, heat stabilities, and kinetic properties. ACKNOWLEDGMENTS We thank Dorothy M. Rutherford and Wallace W. Holland for their excellent technical assistance. ER -