Studies on the subunit structure and molecular size of the human alcohol dehydrogenase isozymes determined by the different loci, ADH1ADH2, and ADH3
Studies on the subunit structure and molecular size of the human alcohol dehydrogenase isozymes determined by the different loci, ADH1ADH2, and ADH3
复制标题
由不同位点ADH1ADH2和ADH3确定的人乙醇脱氢酶同工酶亚基结构和分子大小的研究
DOI：
10.1111/j.1469-1809.1973.tb00604.x
复制
发表时间：
1973
影响因子：
1.9
通讯作者：
H. Harris
中科院分区：
文献类型：
--
作者：
Moyra J. Smith;D. Hopkinson;H. Harris
Ann. Uenet.，Lond.（1973），36，401印在Ureat Britain上由不同位点确定的人类乙醇脱氢酶同工酶的亚单位结构和分子大小的研究，ADH，ADH，和A D H，由MOYRA SMITH，D. A.霍普金斯和哈里哈里斯M.R.C.已经提出（Smith，Hopkinson和Harris 1971，1972），人乙醇脱氢酶（ADH）由三个独立的结构基因座决定，命名为ADH α、ADH β和ADH β，它们分别编码结构上不同的多肽α、β和γ。已获得证据表明在A D H和A D H基因座的每一个上存在两个共同的等位基因，命名为A D H ;和A D H ;和A D H;和ADH;，其编码相应多肽的结构上不同的形式（分别为pl、pz和yl、y 2）。根据该假设，人ADH的同工酶是二聚体，并且任何一种特定同工酶可以是同源二聚体，由两个相同的多肽（例如0101、plpl、y 'y'等）组成。由一个基因座上的特定等位基因编码，或由两个不相同的多肽组成的异二聚体（例如，~$1、ay 1、ay 2等）由不同基因座的等位基因编码，或异二聚体但由同一基因座的不同等位基因编码（例如y1 y2）。组织提取物电泳后实际观察到的同工酶似乎取决于三个位点的相对活性，它们因组织而异，也随发育而异。因此，在肝脏中，由ADH，多肽组成的同源二聚体aa同工酶在早期胎儿生活中占主导地位，但随后出现ADH，多肽，可以检测到异源二聚体ap和同源二聚体pp同工酶。在出生后的第一年，ADH，多肽也出现和复杂的混合物的同源二聚体（0101，和y y）和异源二聚体（ap，ay和By）同工酶可以检测到从儿童和成人的肝脏。相比之下，肺组织的同工酶模式在胎儿和成人样品中都是简单的，并且仅由ADH基因座确定的1/3多肽组成。在肾脏和胃肠道中，ADH多肽在早期胎儿中占主导地位，并且在各自的纯合子中可以容易地看到同型二聚体的y1 y1和y2 y2同工酶，而在杂合子（ADH，2-1）中，它们与杂合的异二聚体的y1 y2同工酶一起出现。在成人胃肠道标本中，由ADH_1位点确定的ADH同工酶也占优势，但也可见到微量的ADH_1型同工酶。在成人肾脏中，通过仔细匀浆冰冷的死后组织，现已发现确实存在由A D H 1基因座决定的同工酶，这与早先所认为的相反（Smith等，1971），但总ADH活性的大部分可归因于A D H 1基因座。本文主要是关于ADH同工酶不同假定亚基的解离和重组的体外杂交实验结果。研究结果支持上述假设。此外，我们描述了使用凝胶过滤柱色谱法来确定各种同工酶的分子大小和通过羧甲基（CM）纤维素上的离子交换色谱分离各个同工酶的实验。
Ann. Hum. Uenet., Lond. (1973), 36, 401 Printed in Ureat Britain Studies on the subunit structure and molecular size of the human alcohol dehydrogenase isozymes determined by the different loci, ADH,, ADH,, and A D H , BY MOYRA SMITH, D. A. HOPKINSON AND HARRY HARRIS M.R.C. Human Biochemical Genetics Unit, Galton Laboratory, University College London It has been proposed (Smith, Hopkinson & Harris 1971, 1972) that human alcohol dehydro- gellase (ADH) is determined by three separate structural gene loci, designated ADH,, A D H , and ADH,, which code for structurally different polypeptides a, /3 and y respectively. Evidence has been obtained for the occurrence of two common alleles at each of the A D H , and A D H , loci, designated A D H ; and A D H ; and A D H ; and ADH;, which code for structurally distinct forms of the corresponding polypeptides (pl, pz and yl, y 2 respectively). According t o the hypothesis the isozymes of human ADH are dimers and any one particular isozyme may be homodimeric, consisting of two identical polypeptides (e.g. 0101, plpl, y'y', etc.) coded by a specific allele at one of the loci, or heterodimeric, consisting of two non-identical polypeptides (e.g. ~$1, ay', ay2, etc.) coded by alleles a t separate loci or heterodimeric but coded by different alleles a t the same locus (e.g. y1y2). The isozymes actually observed after electrophoresis of tissue extracts appear t o depend on the relative activities of the three loci and they vary from tissue to tissue and also with development. Thus, in liver, the homodimeric aa isozyme consisting of ADH, polypeptides predominates in early foetal life but later ADH, polypeptides appear and the heterodimeric ap and the homodimeric pp isozymes can be detected. During the first year of post-natal life ADH, polypeptides also appear and a complex mixture of homodimeric (0101, and y y ) and heterodimeric (ap, ay and By) isozymes can be detected in liver from children and adults. I n contrast, the isozyme pattern of lung tissue is simple in both foetal and adult samples and consists only of /3 polypeptides determined by the ADH, locus. In kidney and gastro-intestinal tract the ADH, polypeptides predominate in early foetal life and the homodimeric jsozymes y1y1 and y2y2 can be readily seen in the respective homozygotes, while in the heterozygotes (ADH, 2-1) they occur together with the hybrid heterodimeric y1y2 isozyme. I n adult gastro- intestinal tract specimens the ADH isozymes determined by the A D H , locus also predominate but traces of the ADH, type isozymes are seen as well. I n adult kidney it has now been found by careful homogenization of ice-cold post-mortem tissue that isozymes determined by the A D H , locus do occur, contrary t o what was thought earlier (Smith et al. 1971) but most of the total ADH activity can be attributed to the A D H , locus. The present paper is principally concerned with the results of in vitro hybridization experi- ments involving the dissociation and recombination of the postulated subunits of the different ADH isozymes. The findings support the hypothesis outlined above. I n addition, we describe experiments using gel filtration column chromatography to determine the molecular size of the various isozymea and the separation of the individual isozymes by ion exchange chromatography on carboxymethyl (CM) cellulose.