isozymen.

1959 Markert & Møller in Proc. National Acad. Sci. U.S.A. 45 753 We propose, therefore, to use the term isozyme to describe the different molecular forms in which proteins may exist with the same enzymatic activity.

1968 T. Wieland in Thoai & Roche Homologous Enzymes & Biochem. Evolution iii. 3 The second group of multiple forms consists of the so called ‘isozymes’. They may be defined as the multiple molecular forms of an enzyme existing within a single organism.

1968 T. Wieland in Thoai & Roche Homologous Enzymes & Biochem. Evolution iii. 9 Isozymes are multiple forms of enzymes, which occur in one cell or—less strictly defined—in one organ of an organism.

1968 New Scientist 21 Mar. 649/2 LDH exists in five very slightly different forms... Each version is known as an isozyme of LDH, and each will catalyze the final glycolysis step.

1959 Markert & Møller in Proc. National Acad. Sci. U.S.A. 45 756 The relative enzymatic activity disposed in each isozymic band.

1973 Nature 3 Aug. 261/2 The genes for isozymic forms of various enzymes are often not linked to each other.