Purification of acid proteinases from calf brain.
The purification was begun with acetone precipitation of minced brain tissue with subsequent proteinase extraction with 0.2 M sodium formate buffer (pH 3.5), reprecipitation with acetone and dialysis. Chromatographic separation on Sephadex G-200, DEAE-Sephadex A-50 and CM-cellulose was carried out in that order. Upon ion-exchange chromatography multiple forms of acid proteinases emerged; two of them were obviously identical with cathepsin D (EC 3.4.23.5), and two of them exhibited properties of cathepsin B (EC 3.4.22.1).
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002417:Cattle; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D010450:Endopeptidases / Q000302:isolation & purification*
D010450:Endopeptidases