STUDIES ON PROPERTIES OF HUMAN ALCOHOL-DEHYDROGENASE ISOENZYMES DETERMINED BY DIFFERENT LOCI ADH1, ADH2, ADH3
STUDIES ON PROPERTIES OF HUMAN ALCOHOL-DEHYDROGENASE ISOENZYMES DETERMINED BY DIFFERENT LOCI ADH1, ADH2, ADH3
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DOI：
10.1111/j.1469-1809.1973.tb01814.x
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发表时间：
1973-01-01
影响因子：
1.9
通讯作者：
HOPKINSON, DA
中科院分区：
文献类型：
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作者：
SMITH, M;HOPKINSON, DA
先前的研究表明，人类乙醇脱氢酶 (ADH) 由三个独立的结构基因位点（ADH、ADH 和 ADH）决定，并且有证据表明 ADH 和 ADH 基因位点具有遗传多态性（Smith、Hopkinson & Harris，1971、1972）。从体外“杂交”实验中获得了令人信服的证据，支持这样的假设：人类 ADH 同工酶是二聚体，并且任何一种特定同工酶可能是由两个相同的多肽亚基组成的同二聚体，或由由不同基因位点或同一位点上的不同等位基因编码的两个不同亚基组成的异二聚体（Schenker，Teeple 和 von Wartburg，1971；Jornvall 和彼得鲁斯科，1972；史密斯、霍普金森和哈里斯，1973）。还发现了。这些同工酶具有相似的分子量，但根据其亚基组成，在淀粉凝胶上的相对电泳迁移率以及以乙醇、戊醇和丁醇为底物的相对活性方面有所不同（Smith 等，1972）。本文介绍了对由三个不同基因位点决定的人 ADH 同工酶底物特异性的进一步研究，以及各种同工酶的抑制特性、pH 活性谱和体外稳定性的研究结果。先前使用粗制组织匀浆和纯化制剂的工作表明，人肝脏 ADH 具有广泛的底物特异性，并且能够在 NAD 存在下催化多种醇的氧化，并在 NADH 存在下催化许多相应醛的还原（von Wartburg, Bethune & Vallee, 1964; von Wartburg, Papenberg & Aebi, 1965; von Wartburg & Papenberg, 1966；冯·瓦特堡，1971）。几种具有药理学活性的醇，例如 Ronicol（对-吡啶基甲醇）和 Myanesin（甲苯氧基-1, 2-丙二醇）和醛，例如水合氯醛和乙缩醛（对羟基丁醛）也已被证明可以作为人肝脏 ADH 的底物（von Wartburg & Schurch，1968）。硫脲、吡唑、乙醛和乙醇的几种卤素衍生物以及各种金属结合剂等抑制剂的作用也已在先前的文献中进行了描述，特别是与酶的“常见”和“非典型”形式的比较（Ton Wartburg et ul. 1964, 1965, 1966, 1968；Blair & Vallee, 1966）。目前的工作计划作为这些早期研究的延伸，考虑到最近定义的人类 ADH 同工酶的电泳异质性和遗传多态性，并进一步测试上述遗传假设的有效性，即人类 ADH 由三个独立的结构基因位点 ADH、ADH 和 ADH 决定。
Previous studies indicate that human alcohol dehydrogenase (ADH) is determined by three separate structural gene loci (ADH,, ADH, and ADH,) and there is evidence for genetic polymoqhism at the ADH, and ADH, loci (Smith, Hopkinson & Harris, 1971, 1972). Convincing evidence has been obtained from in witro ‘hybridization’experiments to supportthe hypothesis that the human ADH isozymes are dimers and that any one particular isozyme may be a homodimer consisting of two identical polypeptide subunits or a heterodimer consisting of two nonidentical subunits coded by different gene loci or different alleles at the same locus (Schenker, Teeple & von Wartburg, 1971; Jornvall & Pietruszko, 1972; Smith, Hopkinson & Harris, 1973). It has also been found tha. t the isozymes are of similar molecular weight but differ according to their subunit composition in their relative electrophoretic mobilities on starch gels and in their relative activities with ethanol, wamyl alcohol and butanol as substrates (Smith et ul. 1972). The present paper describes further investigations of the substrate specificities of the human ADH isozymes determined by the three different gene loci and also the results of studies on the inhibition characteristics, pH activity profiles and in vitro stabilities of the various isozymes. Previous work using crude tissue homogenates and also purified preparations indicated that human liver ADH has a broad substrate specificity and is capable of catalysing the oxidation of a wide range of alcohols in the presence of NAD and the reduction of many corresponding aldehydes in the presence of NADH (von Wartburg, Bethune & Vallee, 1964; von Wartburg, Papenberg & Aebi, 1965; von Wartburg & Papenberg, 1966; von Wartburg, 1971). Several pharmacologically actiTe alcohols such as Ronicol (P-pyridyl carbinol) and Myanesin (toloxy-1, 2-propanediol) and aldehydes such as chloral hydrate and Acetaldol (P-hydroxybutyraldehyde) have also been shown to act as substrates for human liver ADH (von Wartburg & Schurch, 1968). The effects of inhibitors such as thiourea, pyrazole, several halogen derivatives of acetaldehyde and ethanol and various metal binding agents have also been described in the previous literature, particularly in connexion with comparisons of the ‘usual’and ‘atypical’forms of the enzyme (Ton Wartburg et ul. 1964, 1965, 1966, 1968; Blair & Vallee, 1966). The present work was planned as an extension of these earlier studies, to take into account the recently defined electrophoretic heterogeneity and genetic polymorphism of the human ADH isozymes and also to test further the validity of the genetic hypothesis outlined above that human ADH is determined by three separate structural gene loci, ADH,, ADH, and