“…Peptide analyses have revealed that the peptide prof'des of Class I ADH (homo-or heterodimers of a,/3, and 3, subunits), Class II ADH (dimers of zr subunits), and Class III ADH (dimers of X subunits) differ significantly from each other while ct,/3, and 3' subunits within Class I have very similar profiles [14]. Also, subunits from one class do not form heterodimers with subunits from the other two classes [6,8,10]. Class I ADH isozymes are the products of three gene loci, ADHI, ADH2, and ADH3, which encode the three different polypeptide chains designated c~, /3, and -/, respectively [I0].…”