A rapid method for the purification of octopine dehydrogenase for the determination of cell metabolites

Summary Unlike other NAD⁺-dependent dehydrogenases, octopine dehydrogenase was not bound by blue Sepharose. A rapid 2-step purification procedure (gel filtration on Sephadex G-100 followed by affinity chromatography on blue Sepharose) resulted in a final preparation of octopine dehydrogenase which had a sp. act. of 65 units/mg protein and was free of contaminating NAD⁺-oxidoreductases. This preparation has been used successfully for the estimation of phospho-L-arginine, L-arginine and octopine in perchloric acid extracts.Supported by a grant from the Deutsche Forschungsgemeinschaft (Ga 241/1).     

Sidedness of the inhibitory effects of diamide on Na and water transport in amphibian skin

Summary Diamide, a thiol-oxidizing agent, blocks cAMP-mediated stimulation of Na and water transport when added to the outer solution bathing frog skin. No inhibition was found with diamide in the inner solution. These effects may be due to a perturbation of the thiol-disulfide status of specific components of the outer membrane of the epithelium.This work was supported by grants No. 3.1300.73 and 3.043-0.76 from the Swiss National Science Foundation.     

Ox-spleen erythropoietic factor: Chromatographic investigations and dosages

Summary The constant proteic fraction, obtained from ox-spleen homogenates by chromatographic elutions, is the main seat of erythropoietic activity in our assay with polycythemic mice.     

Fractionnement des protéines bactériennes par électrophorèse en gel d'acrylamide-agarose

Summary Acrylamide-agarose gel electrophoresis was employed to separate proteins obtained by sonication of various gram negative bacilli. The bulk of bacterial protein migratc at pH 8.7 to the anode, but often some fractions are quickly migrating to the cathode. Some 30 fractions can be distinguished this way. This technique proves interesting for the study of microbial protein metabolism and may easily be applied to numerous bacteria.