人类白细胞中的非氧化乙醇代谢：脂肪酸乙酯合酶活性的检测

Nonoxidative ethanol metabolism in human leukocytes: detection of fatty acid ethyl ester synthase activity.

作者信息

Wright M, Bieser K J, Kinnunen P M, Lange L G

出版信息

Biochem Biophys Res Commun. 1987 Feb 13;142(3):979-85. doi: 10.1016/0006-291x(87)91510-5.

Abstract

Oxidative pathways of alcohol metabolism such as alcohol dehydrogenase usually are not present in human blood and therefore clinical studies correlating ethanol metabolism with alcohol abuse syndromes have not been performed. To assess the activity of nonoxidative ethanol metabolism in blood, we assayed for the activity of fatty acid ethyl ester synthase, a pathway recently described as abundant in the human organs most commonly damaged by alcohol. Indeed, peripheral human leukocytes contain detectable fatty acid ethyl ester synthase activity: 1.2 X 10(6) leukocytes from 10 ml blood catalyze the synthesis of ethyl oleate at 1.4 nmol/4 hr. The reaction is linear with respect to cell number and expended time; Km oleate = 600 microM, Km ethanol = 600 mM. DEAE cellulose chromatography partially purifies synthase activity into a minor and major form (activity ratio = 10/1). Thus, gene products exist in human blood that recognize ethanol and whose biological activity is conveniently assayable for clinical investigations of alcohol metabolism and abuse.

摘要

酒精代谢的氧化途径，如酒精脱氢酶，通常不存在于人体血液中，因此尚未进行将乙醇代谢与酒精滥用综合征相关联的临床研究。为了评估血液中非氧化乙醇代谢的活性，我们检测了脂肪酸乙酯合酶的活性，这是最近被描述为在最常受酒精损害的人体器官中大量存在的一条途径。实际上，人外周血白细胞含有可检测到的脂肪酸乙酯合酶活性：10毫升血液中的1.2×10⁶个白细胞在4小时内催化油酸乙酯的合成量为1.4纳摩尔。该反应在细胞数量和反应时间方面呈线性关系；油酸的米氏常数（Km）=600微摩尔，乙醇的米氏常数（Km）=600毫摩尔。通过二乙氨基乙基纤维素色谱法可将合酶活性部分纯化为主、次两种形式（活性比为10/1）。因此，人体血液中存在能够识别乙醇的基因产物，其生物活性便于进行酒精代谢和滥用的临床研究检测。