The separation of lactate dehydrogenase X from other lactate dehydrogenase isozymes of mouse testes by affinity chromatography

Abstract

There is now substantial evidence that the sperm 'specific' lactate dehydrogenase (LDH.), isozyme LDH-X has enzymatic and immunological properties different from LDH-1 and LDH-5 .LDH-X is encoded by a separate gene locus which is only active during the primary spermatocyte stage of the spermatogenic cycle and is apparently inactive in all other cetls of the organism 14,s ] .Since quantitative and qualitative changes of LDH-X may affect male fertility [6] and since an antiserum to LDH-X seems to suppress prelacy in the mouse 173, we were interested in purifying this enzyme.Previous attempts at isolating LDH-X from different mammalian species, e.g.those recently carried out on mouse testes [ 1,3], have used nonspecific purification steps.However, when performing affinity chromatography of mouse testicular LDH according to a modi~cation of the method of O'Carra and Barry [8] we found that LDH-X, in contrast to the other isozymes, had no affinity for the sepharose linked oxamate .This binding difference facilitates a simple separation of the sperm 'specific' LDH-X from the other LDH isozymes.