Identification of lactate dehydrogenase-X translated in vitro from mouse testicular poly A-containing mRNA.

1. The LDH-X polypeptide was specifically immunoprecipitated from the cell-free translation products of poly A-containing mRNA from mouse testes, and it represents 1-2% of the total proteins synethesized in vitro. 2. The in-vitro synthesized LDH-X polypeptide appears to have the same mol. wt of 36,000 as mouse authentic LDH-X and, thus, any presequence of LDH-X must be very short, if present at all. 3. The LDH-X was not found in the mouse liver mRNA translation products immunoprecipitated by anti-LDH-X antibodies.