CARBONIC-ANHYDRASE ACTIVITY IN ACETATE GROWN METHANOSARCINA-BARKERI
CARBONIC-ANHYDRASE ACTIVITY IN ACETATE GROWN METHANOSARCINA-BARKERI
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DOI：
10.1007/bf00414428
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发表时间：
1989-01-01
影响因子：
2.8
通讯作者：
THAUER, RK
中科院分区：
文献类型：
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作者：
KARRASCH, M;BOTT, M;THAUER, RK
细胞提取物（27000 ×发现乙酸盐培养的巴氏甲烷八叠球菌的碳酸酐酶活性（0.41 U/mg蛋白质），其在加热或与蛋白酶K温育时丧失。Diamox（表观Ki = 0.5 mM）、叠氮化物（表观Ki = 1 mM）和氰化物（表观Ki = 0.02 mM）可抑制该活性。这些和其他性质表明古细菌含有碳酸酐酶（EC 4.2.1.1）。证明该蛋白可能位于细胞质中。甲醇或H_2/CO_2生长细胞的M.巴克氏体没有显示或仅显示非常少的碳酸酐酶活性。将这些细胞转移到乙酸盐培养基后，活性被“诱导”，表明该酶在乙酸盐发酵中对CO2和CH 4的功能。有趣的是，脱硫菌postgatei和Desulfotomaculum acetoxidans，氧化乙酸2 CO2与硫酸作为电子受体，也被发现表现出碳酸酐酶活性（0.2 U/mg蛋白质）。
Cell extracts (27000 .times. g supernatant) of acetate grown Methanosarcina barkeri were found to have carbonic anhydrase activity (0.41 U/mg protein), which was lost upon heating or incubation with proteinase K. The activity was inhibited by Diamox (apparent Ki = 0.5 mM), by azide (apparent Ki = 1 mM), and by cyanide (apparent Ki = 0.02 mM). These and other properties indicate that the archaebacterium contains the enzyme carbonic anhydrase (EC 4.2.1.1). Evidences is presented that the protein is probably located in the cytoplasm. Methanol or H2/CO2 grwon cells of M. barkeri showed no or only very little carbonic anhydrase activity. After transfer of these cells to acetate medium the activity was "induced" suggesting a function of this enzyme in acetate fermentation to CO2 and CH4. Interestingly, Desulfobacter postgatei and Desulfotomaculum acetoxidans, which oxidize acetate to 2 CO2 with sulfate as electron acceptor, were also found to exhibit carbonic anhydrase activity (0.2 U/mg protein).