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Annals of Human Genetics | 1973

Esterase D: a new human polymorphism

D. A. Hopkinson; M. A. Mestriner; J. Cortner; Harry Harris

Tashian (1 961, 1969) demonstrated several different esterases in human red cells by electrophoresis. Azo dye coupling techniques were used to locate the esterase isozymes. Three main groups of esterases were defined on the basis of their electrophoretic properties, substrate specificities and inhibition characteristics, and were referred to as the A, B and C esterases. Isozymes of carbonic anhydrase, which also has esteratic activity, were also demonstrated using essentially similar techniques. Fig. 1, which is based on Tashians work, shows a diagrammatic representation of the various red cell esterase isozymes after electrophoresis of haemolysates in borate starch gels at pH 8.0-8-6. The A esterases are subdivided into three sets of isozymes, A,, A, and As, which differ electrophoretically and in their storage properties and inhibition characteristics ; also the As isozymes have a larger molecular size than A, or A,. Inherited variants of these isozymes are rare in man but two different variant phenotypes have been reported (Tashian & Shaw, 1962; Tashian, 1965). They are of particular interest because each of the three subgroups of A esterase are affected in the variant isozyme patterns suggesting that A,, A, and As contain a common subunit. Family studies on one of the variants indicated that this esterase A locus is autosomal. Esterase B is primarily a butyryl esterase and no variants have been reported in population surveys to date. Esterase C is a rather weakly staining invariate acetyl esterase. Several different variants of the carbonic anhydrase isozyme CA I (or B) have been recorded in the literature (see Tashian, 1969) but they are all individually rare except in certain cases where they have been identified in small isolated populations, e.g. the CA I, variant in Guam and Saipan. The CA 1 locus is autosomal and the variants do not affect CA I1 (or C). The latter is determined at a separate autosomal locus and recent studies (Moore, Funakoshi & Deutsch, 1971) using an immunological detection technique have led to the recognition of a genetic polymorphism of CA 11 in Blacks. Another esterase which occurs in red cells is acetylcholinesterase. This is membrane bound and not therefore readily detected by electrophoresis of simple lysates. The present paper describes yet a further human red cell esterase. It will be referred to as esterase D (Es D). It was discovered by the use of the fluorogenic substrates, 4-methyl-umbelliferyl acetate and 4-methyl-umbelliferyl butyrate, for the detection of esterase isozymes after starch gel electrophoresis. The isozymes of this new esterase are different from the red cell A, B aiid C esterases, the carbonic anhydrase isozymes, and from acetylcholinesterase in their


Annals of Human Genetics | 1971

Developmental changes and polymorphism in human alcohol dehydrogenase

Moyra Smith; D. A. Hopkinson; Harry Harris

1. Human alcohol dehydrogenase (ADH) has been investigated by spectrophotometry assay and by starch‐gel electrophoresis.


Annals of Human Genetics | 1968

Inherited variations in human phosphohexose isomerase.

James C. Detter; Peter O. Ways; Eloise R. Giblett; Marjorie A. Baughan; D. A. Hopkinson; S. Povey; Harry Harris

1. The elctrophoretic pattern of phosphohexose isomerase has been examine in the blood of 3397 unrelated individuals from several different populations groups.


Annals of Human Genetics | 1969

Further data on the adenosine deaminase (ADA) polymorphism and a report of a new phenotype

D. A. Hopkinson; P. J. L. Cook; Harry Harris

In a study of human red cell adenosine deaminase (ADA) three different types of isozyme patterns were identified (Spencer, Hopkinson & Harris, 1968). One phenotype designated ADA 1 was found in about 89 % of the English population, the second phenotype, ADA 2-1, was found in about 11 yo of the population and the third phenotype, designated ADA 2, was seen only once in a survey of 580 unrelated English people. Sixty-seven families were studied and the family data suggested that the three ADA phenotypes were determined by two autosomal alleles ADA1 and ADA2; phenotypes ADA 1 and ADA 2 corresponding to the homozygous genotypes ADAlADAl and ADAaADA2 respectively and phenotype ADA 2-1 corresponding to the heterozygous combination ADA1ADA2. This paper contains further family data and more extensive population data on the ADA polymorphism and also a description of a new phenotype.


Annals of Human Genetics | 1972

Average heterozygosity per locus in man: an estimate based on the incidence of enzyme polymorphisms

Harry Harris; D. A. Hopkinson

1. Data from electrophoretic surveys of enzymes in European populations are reviewed.


Annals of Human Genetics | 1972

Alcohol dehydrogenase isozymes in adult human stomach and liver: evidence for activity of the ADH3 locus

Moyra Smith; D. A. Hopkinson; Harry Harris

Ann. Hum. Genet., Lond. (1972), 35, 243 Pyinted in Great Britain Alcohol dehydrogenase isozymes in adult human stomach and liver : evidence for activity of the ADH3 locus BY MOYRA SMITH, D. A. HOPKINSON AND HARRY HARRIS M.R.C. Human Biochemical Genetics Unit, Galton Laboratory, University College London I n a previous paper (Smith, Hopkinson & Harris, 1971) we put forward a genetical hypothesis to explain the isozyme patterns of human alcohol dehydrogenase in various tissues and at different times in development. It was suggested that there are three loci each coding for a structurally distinct type of polypeptide chain; that the isozymes are dimers; and that any particular isozyme may be made up of two identical subunits coded by a specific allele at one of the loci, or of two non-identical subunits coded by alleles at two separate loci, or of two non-identical subunits coded by different alleles at the same locus. The loci were called ADH,, ADH, and ADH, and the corresponding polypeptide subunits a, /3 and y . At each of the ADH, and ADH, loci the evidence indicated that two different common alleles occur, coding for structurally distinct forms of the corresponding polypeptide. According to the hypothesis, the isozymes in the cells of a particular tissue at a given time in development depend on the relative activities of the three loci. Thus in liver, a polypeptides determined by ADH, appear to predominate in early foetal life, but in the course of foetal develop- ment /3 polypeptides determined by ADH, appear in increasing amounts, so that while in the early foetus the main isozyme observed is aa, as development proceeds the isozymes a/3 and /3/3 appear in increasing quantities. I n adult liver ADH, activity exceeds ADH, activity. In lung, kidney and the gastro-intestinal tract the total alcohol dehydrogenase activity is very much less than in liver, and the contributions made by the different loci to the total activity show striking differences. I n lung, polypeptides determined by ADH, appear to predominate both in foetal life and in the adult. I n kidney y polypeptides determined by ADH, predominate throughout foetal life but diminish after birth, and in the adult the ADH activity that can be detected appears to be mainly derived from ADH,. I n the gastro-intestinal tract y polypeptides determined by ADH, are found as in the kidney to predominate throughout foetal life. But because of lack of suitable material the situation in adult gastro-intestinal tract was not established in our earlier work. The findings reported in the present paper are concerned with two aspects of the problem. The first concerns the ADH isozymes in the adult gastro-intestinal tract. I n our previous studies we had attempted to examine this question using material from the intestine obtained at autopsy. However, sufficiently clear and consistent isozyme patterns were not obtained. We have now found, however, that adult stomach samples from autopsy give clearly defined isozyme patterns and these correspond to those previously observed in foetal kidney and foetal intestine. Thus it appears that most of the ADH activity in adult stomach is derived from the ADH, locus. The second topic we consider here concerns certain isozymes which had previously been observed in adult liver, but which at that time could not be easily accounted for in terms of the three-locus hypothesis. These isozymes occur in addition to the aa, a/3 and /3/3 isozymes of liver, and it had been noted that they show marked variations from individual to individual in their


Annals of Human Genetics | 1971

Inherited variants of human nucleoside phosphorylase

Yvonne H. Edwards; D. A. Hopkinson; Harry Harris

1. A method, for the starch gel electrophoresis of human nucleoside phosphorylase (NP) is described. Multiple NP isozymes were found in most human tissues and the best resolution of these isozymes was achieved by electrophoresis in a buffer system containing lithium ions.


Annals of Human Genetics | 1968

A third phosphoǵlucomutase locus in man

D. A. Hopkinson; Harry Harris

1. Investigation of human tissue extracts by starch gel electrophoresis has vevealed three groups of isozymes with PGM activity.


Annals of Human Genetics | 1966

Rare phosphoglucomutase phenotypes

D. A. Hopkinson; Harry Harris

1. PGM phenotypes have been determined by starch‐gel electrophoresis in more than 2000 unrelated ‘ English’ people and several smaller samples from other populations.


Annals of Human Genetics | 1974

The incidence of rare alleles determining electrophoretic variants: data on 43 enzyme loci in man

Harry Harris; D. A. Hopkinson; Elizabeth B. Robson

Inherited variants of many different enzymes have been discovered by electrophoretic techniques. In general they can be attributed to alleles which originated by mutation in individuals in earlier generations a t the loci coding for the structures of the particular enzymes. Population surveys indicate that such alleles vary very widely in their incidence, some being relatively common and others extremely rare. Up till now attention has mainly focused on the common alleles which give rise to the so-called enzyme polymorphisms. It has been found, for example, that polymorphism due to common alleles which determine electrophoretically distinct enzyme variants appears to occur in human populations at some 25-30% of loci coding for enzyme structure, and that the average heterozygosity per locus for such alleles is around 0.07 (Harris & Hopkinson, 1972). The same general phenomenon has of course also been demonstrated in a variety of other species and the recognition of its widespread occurrence has generated a great deal of discussion and not a little controversy about its fundamental biological significance. However, so far not much attention has been paid to relatively rare alleles which also give rise to electrophoretically detectable enzyme variants. This is no doubt, in part, because although many such variants have been reported, little systematic data on their incidence at different loci has been available. The purpose of the present paper is to present an extensive body of data which gives information about the incidence of such rare alleles over a wide range of loci. We believe that such data may provide an observational base which may help to extend the scope of current discussions about the nature and significance of enzyme polymorphism in particular, and about the character of enzyme diversity among the individual members of natural populations in general.

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Harry Harris

University College London

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S. Povey

University College London

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Moyra Smith

University College London

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