Yarlett N, Hann A C, Lloyd D, Williams A
Biochem J. 1981 Nov 15;200(2):365-72. doi: 10.1042/bj2000365.
This paper reports for the first time the presence in the anaerobic rumen ciliate Dasytricha ruminantium (Schuberg) of microbody-like organelles, about 0.5 micrometer diameter, with a granular matrix and an equilibrium density of approx. 1.18 g/ml. These organelles can be isolated in a fraction sedimented at 10(5) g-min that contains 67% of the total pyruvate synthase (EC 1.2.7.1), 66% of the hydrogenase (EC 1.18.3.1) and 20% of the lactate dehydrogenase (EC 1.1.1.27). Thus in several respects this fraction is enzymically similar to those containing hydrogenosomes in some other parasitic anaerobic protozoa (the trichomonads). However, in contrast with the hydrogenosomes of trichomonads, the oxygen-tolerant enzyme malate dehydrogenase (decarboxylating) (EC 1.1.1.40) is not particulate, but occurs only in the cytosol. These results enable the proposal of a scheme for the pathway of product formation (acetate, lactate, CO2 and H2) from carbohydrates.
本文首次报道了在厌氧瘤胃纤毛虫——反刍类双毛虫（Schuberg）中存在直径约0.5微米、具有颗粒状基质且平衡密度约为1.18克/毫升的微体样细胞器。这些细胞器可在以10⁵g·min离心沉淀的组分中分离得到，该组分含有总丙酮酸合酶（EC 1.2.7.1）的67%、氢化酶（EC 1.18.3.1）的66%和乳酸脱氢酶（EC 1.1.1.27）的20%。因此，在几个方面，该组分在酶学上与其他一些寄生性厌氧原生动物（毛滴虫）中含有氢化小体的组分相似。然而，与毛滴虫的氢化小体不同，耐氧酶苹果酸脱氢酶（脱羧）（EC 1.1.1.40）不是颗粒状的，仅存在于胞质溶胶中。这些结果使得能够提出一个关于碳水化合物形成产物（乙酸、乳酸、二氧化碳和氢气）途径的方案。
