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Cathechol‐O‐methyltransferase activity in cultured human skin fibroblasts from controls and patients with dystonia musculorum deformans
Author(s) -
Breakefield Xandra O.,
Braverman Muriel,
Riker Donald Kay,
Giller Earl L.
Publication year - 1981
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.490060310
Subject(s) - catechol o methyl transferase , monoamine oxidase , enzyme , dystonia , endocrinology , fibroblast , enzyme assay , medicine , monoamine neurotransmitter , pargyline , catabolism , monoamine oxidase b , biochemistry , chemistry , biology , serotonin , allele , in vitro , neuroscience , receptor , gene
Fibroblasts provide a source of living cells that can be obtained easily from humans and used to evaluate inherited differences in the activities of enzymes important in neurotransmitter and drug metabolism. Here, we describe biochemical characteristics of catechol‐O‐methyltransferase (COMT, EC 2.1.1.6) activity in homogenates of cultured human skin fibroblasts. Many properties of the enzyme, including apparent affinity for dihydroxybenzoic acid and Sadenosyl methionine, optimal pH and (Mg ++ ), and inhibition by Ca ++ , are similar to those reported in lysates of human erythrocytes. Culture and assay conditions have been established for optimal and reproducible measurement of COMT activity in individual fibroblast lines. In 16 control lines, COMT activity ranged from 115 to 263 pmol/min/mg protein with a mean of 181 pmol/min/mg protein. Enzyme activity did not vary with the age or sex of the donor. The COMT activities in fibroblasts from eight patients with dystonia musculorum deformans, an inherited movement disorder of unknown etiology, were not significantly different from controls. Monoamine oxidase (MAO, EC 1.4.3.4) type A activity was measured in 12 lines from patients with dystonia, and values did not differ significantly from age‐ and sex‐matched controls. We conclude that inherited variation in activity of these two catabolic enzymes is not sufficient to explain alterations in monoamine metabolism described in this disorder.