Jacobson K B, Manos R E, Wadzinski F A
Biology Division, Oak Ridge National Laboratory, Tennessee 37831.
Biotechnol Appl Biochem. 1987 Oct;9(5):368-79.
Anaerobic conditions are necessary to prevent the autoxidation of tetrahydrobiopterin. An enzymatic method for achieving such an anaerobic condition is shown to be obtained by a lactate oxidase activity in the membrane of Escherichia coli when the enzyme concentration exceeds 0.05 unit/ml. A procedure is described for partial purification of the membrane fragment that involves salt precipitation and gel sieve chromatography on Bio-Gel A-50m. The rate of removal of oxygen is used to define the enzyme activity, to determine stability during storage, and to define conditions for stabilization of tetrahydrobiopterin. A second assay procedure that measures the rate of reduction of resazurin is described and is useful when the enzyme concentration is low.
厌氧条件对于防止四氢生物蝶呤的自氧化是必要的。当酶浓度超过0.05单位/毫升时，已证明通过大肠杆菌膜中的乳酸氧化酶活性可实现这样的厌氧条件。描述了一种用于部分纯化膜片段的方法，该方法包括盐沉淀和在Bio-Gel A-50m上进行凝胶过滤色谱。用氧气去除率来定义酶活性、确定储存期间的稳定性以及确定四氢生物蝶呤的稳定条件。还描述了第二种测定方法，该方法测量刃天青的还原速率，当酶浓度较低时该方法很有用。
