ScienceAsia 1 (1975): 057-071 |doi: 10.2306/scienceasia1513-1874.1975.01.057

THE PURIFICATlON 0F LACTATE DEHYDROGENASE ISOZYMES LDH-A₄, LDH-B₄ AND LDH-C₄ FROM HUMAN TISSUES

M.R. JISNUSON SVASTI and SUMALEE VIRIYACHAI.

Summary: We have purified all three of the homotetrameric isozymes of human lactate dehydrogenase in milligram quantities. LDH-A₄ was purified 970-fold from human liver to a specific activity of 283 I.U./mg with a yield of 26.5.%; LDH-B₄. was purified 60-fold from hwnan heart to a specific activity of 168 I.U./mg with a yield of 72.5 %; LDH-C₄ WQS purifted 586-fold from human testes to a specific activity of 80 I.U./mg with a yield of 22%. On polyacrylamide gel electrophoresis, LDH-A₄ and LDH-B₄ were shown to be homogeneous with respect to enzyme activity and to protein. The minor contaminants present in the LDH-C₄ preparation amount to less than 5 % of the total protein and less than 2 % of the LDH activity. The relative merits and drawbacks of the procedures used are discussed.

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Department of Biochemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok

Received 30 January 1975