Mitochondrial electron transport enzymes in normal and leukemic human leukocytes.

T HE DISCOVERY OF CHANGES in the metabolism of malignant cells, as demonstrated by enzymologic technics, will lead, hopefully, to the better understanding of the nature of the neoplastic process, which is the ultimate necessity for satisfactory therapy. In 1963, Silber, Huennekens, and Gabrio1 reported the presence of increased amounts of two pyridine nucleotide transhydrogenase enzymes in human leukemic leukocytes. The TD transhydrogenase enzyme catalyses the transfer of hydrogen between reduced triphosphopyridine nucleotide (TPNH) and diphosphopyridine nucleotide (DPN) as shown in the following reaction: TPNH +DPN TD transhydrogenase TPN +DPNH