Isolation of human lactate dehydrogenase isoenzyme X by affinity chromatography

Abstract

Human isoenzyme LDH-X (lactate dehydrogenase isoenzyme X) was isolated from seminal fluid of frozen semen samples by affinity chromatography by using oxamateSepharose and AMP-Sepharose. In the presence of 1.6mm-NAD+, isoenzyme LDH-X does not bind to AMP-Sepharose, whereas the other lactate dehydrogenase isoenzymes do. This is the crucial point in the isolation of isoenzyme LDH-X from the other isoenzymes. The purified human isoenzyme LDH-X had a specific activity of 146 units/ mg of protein.

Mouse Lactate Dchydrogenase (LDH) C4 (Testis) Is Immunochemically Cross‐Reactive with LDH A4 (Muscle) and LDH B4 (Heart)

“…Li etal. [23] repon that the sequence of primary amino acids In mouse LDH C shows greater homology with porcine A than with porcitie B. Since tbe primary structures of mouse LDH A atid LDH B have not been determined, it is difficult to identify presumptive imtnunologically reactive regions that might be recognized by these sera.…”

Separation of rat lactate dehydrogenase isoenzyme C4 from other isoenzymes by affinity and ion-exchange chromatography

“…Lactate dehydrogenase C has been purified from testes of several species, including rat (Schatz & Segal, 1969;Ansari et al, 1980;Chang et al, 1980), bull (Kolb et al, 1970), mouse (Wong et al, 1971;Goldberg, 1972;Lee et al, 1977;Wheat & Goldberg, 1977), rabbit (Wheat & Goldberg, 1977) and human (Svasti & Viriyachai, 1975;Wheat & Goldberg, 1977;Kolk et al, 1978;Toowicharanont & Svasti, 1980). In spermatozoa and/or testicular extracts from mouse, rabbit, human, ram and dog, only a single molecular form of lactate dehydrogenase C has been detected, i.e.…”