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C Devaux

Publications and source records attributed to C Devaux.

At least 163 records · Page 9Linked to original sources
PubMed1977

Large scale purification of hog renin. Physicochemical characterization.

Renin was purified from 47 kg of hog kidney to produce enough enzyme for enzymatic and physicochemical characterization. The procedure included extraction at pH 3.5 in the presence of protease inhibitors, two ammonium sulfate precipitations, ion exchange chromatography on Sepharose-hexamethylenediamino-pepstatin gel, gel filtration, and isoelectric focusing. Renin, 2.3 mg, with a specific activity of 1,100 GU/mg of protein was obtained with about 70,000-fold purification and 16% overall recovery. The purity criteria were: (1) a single band on sodium dodecyl sulfate (SDS)-gel electrophoresis, (2) same retardation factor on polyacrylamide gel electrophoresis for renin activity, protein and glycoprotein coloration. Renin was characterized by its stability at--20 degrees C, pH 6.5; its molecular weight on SDS-gel electrophoresis, 36,800; its relative mobility on polyacrylamide gel electrophoresis at pH 7.8; its isoelectric point, 5.15; its amino acid composition, which revealed that renin is a glycoprotein; and its Michaelis constant on tetradecapeptide substrate at pH 6.6, Km = 7.7 X 10(-6) M.

Amino Acids↗
PubMed1976

Partial characterization of hog renin purified by affinity chromatography.

A method has been set up to purify renin on a large scale by affinity chromatography using Pepstatin, a potent inhibitor of renin, as a ligand. Pepstatin was covalently coupled to Sepharose via six different spacer 'arms'. The Sepharose-hexamethylenediamino-Pepstatin appeared to be the better derivative for renin purification even at a concentration as low as 160 nmol of Pepstatin/ml of moist gel. Renin was extracted from 100 kg of hog kidneys and semi-purified by ammonium sulfate precipitations and chromatography on DEAE-cellulose. The active fraction (48.5 g of proteins) was applied on a 500-ml affinity column. Renin was eluted in the starting buffer containing 6 M urea. Renin was purified 120-fold by the affinity chromatography step with a 79% recovery. Physico-chemical characterization of highly purified renin was performed. Isoelectrofocusing on a pH gradient from 3 to 6 showed a major peak with an isoelectric point (pI) of 4.95 and a minor peak (pI = 4.70). Polyacrylamide gel electrophoresis, pH 7.8, at different gel concentrations, showed a single peak of renin activity which was found in the major protein band. Molecular size estimated on agarose-acrylamide gel filtration was 40 000. All these physical parameters were similar before and after purification.

Animals↗
PubMed1976

Inhibition of human plasma renin activity by pepstatin.

Pepstatin, a pentapeptide isolated from streptomyces, is a powerful inhibitor of several acid proteases. Its ability to inhibit the renin-angiotensinogen reaction was studied in vitro, in various human plasma. A 50% inhibition of plasma renin activity was obtained with 10(-6)M pepstatin at pH 5.7 and 10(-5)M at pH 7.4. The inhibition of plasma renin activity by pepstatin was studied in hypertensive patients with various plasma renin levels. The inhibitory effect could be demonstrated in patients with low, normal and high renin activity at both pH's. The type of inhibition and the inhibitory constant were investigated by Dixon plot and Lineweaver-Burk plot in three separate experiments. On both representations, a competitive type of inhibition was found with an inhibitory constant of about 1.2 x 10(-6)M.

Humans↗
PubMed1975

[Application of affinity chromatography to the study of renin].

Hog renal renin was measured by a radioimmunoassay of angiotensin I generated during the incubation of the enzyme with an excess of angiotensinogen. The fixation of renin on a sepharose-hexamethylenediamine-pepstatin gel has been studied: the saturation of a 1 ml column of gel is obtained with 900 Goldblatt units of renin. A 70 ml column processing several grams of protein has been used to purify renin by affinity chromatography: a 100 fold purification of renin is achieved in one step. Renin, before and after affinity chromatography, has been analysed by electrofocusing with a pH gradient from 3 to 10; the isoelectric points obtained are respectively 4.8 and 5.0.

Animals↗