THE POSITION OF THE CELL NUCLEUS IN PATHWAYS OF HYDROGEN TRANSFER: CYTOCHROME C, FLAVOPROTEINS, GLUTATHIONE, AND ASCORBIC ACID

Abstract

A study has been made of calf thymus and liver tissue to ascertain the position of the nucleus with respect to mechanisms capable of hydrogen transfer. Although previous work had shown that reduced pyridine nucleotide coenzymes are produced in the course of nuclear metabolism, it has now been established that the flavoprotein system of cytochrome c reductase, cytochrome c, and most, if not all, of other flavoproteins are absent from nuclei. Metabolites capable of cytochrome c reduction, notably ascorbic acid and glutathione, have been demonstrated in the nuclei. Glutathione reductase has been found present in nuclei only to a minor extent, suggesting that nuclear glutathione might function largely in a capacity other than that of hydrogen carrier in the nucleus. Although no enzymatic relation could be established between ascorbic acid and hydrogen transfer in nuclei) it was possible to demonstrate a close association between ascorbic acid concentration and the mitotic process in lily anthers. The significance of the anaerobic character of nuclear metabolism to chromosome function is discussed.