阴道毛滴虫的氢化酶体ATP:AMP磷酸转移酶

Hydrogenosomal ATP:AMP phosphotransferase of Trichomonas vaginalis.

Declerck P J, Müller M

Rockefeller University, New York, NY 10021.

Comp Biochem Physiol B. 1987;88(2):575-80. doi: 10.1016/0305-0491(87)90347-6.

Abstract

ATP:AMP phosphotransferase (adenylate kinase) is present in Trichomonas vaginalis, primarily with hydrogenosomal localization. 2. Adenylate kinase has been purified from hydrogenosome-enriched fractions by solubilization with Triton X-100 and KCl followed by affinity chromatography and gel filtration. 3. The enzyme has a Mr = 28,000, a broad pH optimum of pH 7-9, requirement for Mg2+ and specificity for adenine and deoxyadenine nucleotides. 4. The activity is competetively inhibited by P1,P5-di(adenosine-5') pentaphosphate (Ki 200 nM) and reversibly inactivated by 5,5'-dithiobis-(2-nitrobenzoate). 5. Catalytic properties of this enzyme are similar to those of enzymes from other organisms. Other properties indicate its uniqueness, however, since its molecular mass and Ki for P1,P5-di(adenosine-5'-)-pentaphosphate bring it closer to the mitochrondrial isoenzyme, while it shares a requirement for reduced thiol groups with the cytosolic isoenzyme.

摘要

ATP:AMP磷酸转移酶（腺苷酸激酶）存在于阴道毛滴虫中，主要定位于氢化酶体。2. 通过用 Triton X - 100和KCl溶解，随后进行亲和层析和凝胶过滤，已从富含氢化酶体的组分中纯化出腺苷酸激酶。3. 该酶的分子量为28,000，最适pH范围较宽，为pH 7 - 9，需要Mg2+，对腺嘌呤和脱氧腺嘌呤核苷酸具有特异性。4. 其活性受到P1,P5 - 二（腺苷 - 5'）五磷酸（Ki 200 nM）的竞争性抑制，并被5,5'-二硫代双（2 - 硝基苯甲酸）可逆性失活。5. 这种酶的催化特性与其他生物体中的酶相似。然而，其他特性表明了它的独特性，因为其分子量和对P1,P5 - 二（腺苷 - 5'-）五磷酸的Ki使其更接近线粒体同工酶，而它与胞质同工酶一样都需要还原型巯基。