• 1 January 1980
    • journal article
    • research article
    • Vol. 146  (6) , 231-235
Abstract
The catalytic properties and subcellular distribution of the lactate dehydrogenase isozyme specific for [rat] testis and sperm (LDH X or C4) were analyzed. LDH X catalyzes NAD-linked interconversion .alpha.-ketoacid .dblarw. .alpha.-hydroxyacid with a variety of compounds. Isozyme X is located in the cytosol and in the matrix of a special type of mitochondria present in spermatozoa. An additional shuttle which can transfer H from cytosolic NADH to the mitochondrion by the redox couple .alpha.-hydroxyacid/.alpha.-ketoacid is postulated. Operation of this system was demonstrated in vitro. LDH X may play a role in processes which provide energy to spermatozoa.