Chudomelka P J, Ramaley R F, Murrin L C
Department of Pharmacology, University of Nebraska Medical Center, Omaha 68105-1065.
Neurochem Res. 1990 Jan;15(1):17-24. doi: 10.1007/BF00969179.
Histidine decarboxylase, the synthetic enzyme for histamine, was partially purified from regions of rat or rabbit brain rich in the enzyme. The enzyme was purified using ion exchange and hydrophobic column chromatography and chromatofocusing. Approximately 70-fold and 110-fold enrichments were attained from rat and rabbit brain, respectively. Rat and rabbit brain histidine decarboxylase had isoelectric points of pH 5.4 and 5.6, Km values of 80 microM and 120 microM histidine and Vmax values of 210 and 625 pmol histamine formed/hr-mg protein, respectively. The partially purified histidine decarboxylase from both sources was dependent on pyridoxal phosphate for maximal activity and was inhibited by alpha-fluoromethylhistidine, nickel chloride and cobaltous chloride but was not inhibited by impromidine, alpha-methyldopa, DTNB, zinc chloride or mercuric chloride. The enzyme had a broad pH optimum between pH 7.2 and 8.0. These studies provide further information on the characteristics of mammalian histidine decarboxylase from brain.
组胺合成酶——组氨酸脱羧酶，是从富含该酶的大鼠或兔脑区域中部分纯化得到的。该酶通过离子交换、疏水柱色谱和色谱聚焦法进行纯化。大鼠脑和兔脑中该酶的富集倍数分别约为70倍和110倍。大鼠脑和兔脑组织的组氨酸脱羧酶的等电点分别为pH 5.4和5.6，组氨酸的Km值分别为80 μM和120 μM，Vmax值分别为每小时每毫克蛋白质形成210和625 pmol组胺。来自这两种来源的部分纯化的组氨酸脱羧酶的最大活性依赖于磷酸吡哆醛，并受到α-氟甲基组氨酸、氯化镍和氯化钴的抑制，但不受英普咪定、α-甲基多巴、二硫代硝基苯甲酸、氯化锌或氯化汞的抑制。该酶在pH 7.2至8.0之间具有较宽的最适pH值。这些研究为哺乳动物脑组氨酸脱羧酶的特性提供了进一步的信息。
