On the nature of protein benzoquinone complexes

Summary Proteins form monosubstituted 1,4-benzoquinone derivatives with an excess of reagent via uniformly coloured charge transfer complexes. Some properties of these compounds are reported.Dedicated to Prof. J. Kühnau in commemoration of his 75th birthday.     

Purification of a nuclease from human serum

Summary The purification procedure for a nuclease from human serum is described. It includes ammonium sulfate precipitation, chromatography on DEAE-Sephadex and on Sephacryl-S 200, and preparative electrophoresis. The enzyme, purified about 2000-fold, is homogeneous in a sodium dodecyl sulfate electrophoretic system, where it has a mol. wt of 78,000. The pH optimum lies around pH 6.5; it is a sugar-nonspecific endonuclease.Acknowledgment. This work has been supported by a research grant from Stiftung Volkswagenwerk through the Akademie der Wissenschaften und der Literatur, Mainz. We thank Mrs R. Nehrbass and Mrs C. Wolpert for technical assistance.     

Semen copper in normal and infertile subjects

Summary Concentration of copper in seminal plasma was found to be less than that of normal in cases of oligospermia and azoospermia. It was more in oligoasthenospermia and asthenospermia when compared with that normal. Chances of initiation of sperm motility by copper is discussed alongwith the inhibitory role it plays.Acknowledgment. Authors are thankful to Dr. A. R. N. Setalwad, Assistant Professor in Preventive and Social Medicine for the statistical analysis of the study he did.     

The effect of oxine-5-sulphonic acid on the hepatic drug metabolism in the rat

Summary Oxine-5-sulphonic acid inhibits the metabolism of aminopyrine in the rat liver in vitro. The characteristics of this inhibition vary according to whether the oxidativeN-demethylation of the substrate is determined by the formation of the metabolite 4-aminoantipyrine or by the production of formaldehyde.