Properties of N-Acetylhistamine Deacetylase in Mammalian Brain |
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| Authors: | Linda R Hegstrand Tom H Kalinke |
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| Institution: | William S. Middleton Memorial Veterans Hospital, The Waisman Center on Mental Retardation and Human Development, and Wisconsin Psychiatric Research Institute, Madison, Wisconsin, U.S.A. |
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| Abstract: | Properties of N-acetylhistamine deacetylase in rat brain were studied, utilizing a sensitive coupled radioenzymatic assay. The Km for N-acetylhistamine for this deacetylase was 660 microM and its Vmax was 330 pmol/h/mg protein. N-Acetylhistamine deacetylase activity increased 80% in the presence of 1 mM Mn2+. The Km of Mn2+ was 40 microM. The enzyme is primarily a soluble enzyme with a relatively uniform regional distribution, unlike the distribution for histamine and histidine decarboxylase. Neonatal activity of this enzyme in rat brain is higher than in adult brain. alpha-Fluoromethylhistidine does not affect the activity of N-acetylhistamine, indicating that deacetylation probably does not play a regulatory role in the synthesis of brain histamine. |
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| Keywords: | N-Acetylhistamine deacetylase N-Acetylhistamine Histamine Acetylation Deacetylation α-Fluoromethy1 histidine |
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