从猪肝中纯化3,3-二甲基烯丙基转移酶、香叶基转移酶和异戊烯基焦磷酸异构酶。
The purification of 3,3-dimethylallyl- and geranyl-transferase and of isopentenyl pyrophosphate isomerase from pig liver.
作者信息
Holloway P W, Popják G
出版信息
Biochem J. 1967 Jul;104(1):57-70. doi: 10.1042/bj1040057.
The enzyme catalysing the synthesis of farnesyl pyrophosphate from dimethylallyl pyrophosphate and isopentenyl pyrophosphate, or from geranyl pyrophosphate and isopentenyl pyrophosphate, has been purified 100-fold from homogenates of pig liver. The enzyme has optimum pH 7.9 and requires Mg(2+) as activator in preference to Mn(2+); it is inhibited by iodoacetamide, N-ethylmaleimide, p-hydroxymercuribenzoate and phosphate ions in addition to the products of the reaction, inorganic pyrophosphate and farnesyl pyrophosphate. From product-inhibition studies of the geranyltransferase reaction, the order of addition of substrates to and release of products from the enzyme has been deduced: geranyl pyrophosphate combines with the enzyme first, followed by isopentenyl pyrophosphate. Farnesyl pyrophosphate dissociates from the enzyme before inorganic pyrophosphate. The existence of isopentenyl pyrophosphate isomerase in liver is confirmed. Methods for the preparation of the pyrophosphate esters of isopentenol, 3,3-dimethylallyl alcohol, geraniol and farnesol are also described.
催化从二甲基烯丙基焦磷酸酯和异戊烯基焦磷酸酯，或从香叶基焦磷酸酯和异戊烯基焦磷酸酯合成法呢基焦磷酸酯的酶，已从猪肝匀浆中纯化了100倍。该酶的最适pH为7.9，优先需要Mg(2+)作为激活剂而非Mn(2+)；除了反应产物无机焦磷酸酯和法呢基焦磷酸酯外，它还受到碘乙酰胺、N-乙基马来酰亚胺、对羟基汞苯甲酸酯和磷酸根离子的抑制。通过对香叶基转移酶反应的产物抑制研究，推断出底物与酶结合以及产物从酶中释放的顺序：香叶基焦磷酸酯首先与酶结合，随后是异戊烯基焦磷酸酯。法呢基焦磷酸酯在无机焦磷酸酯之前从酶中解离。证实了肝脏中存在异戊烯基焦磷酸酯异构酶。还描述了异戊烯醇、3,3-二甲基烯丙醇、香叶醇和法呢醇焦磷酸酯的制备方法。
Zotero 插件