Quantification of Ca2(+)-dependent protease activities by hydrophobic and ion-exchange chromatography.

摘要: Hydrophobic and ion-exchange chromatography were compared for yield of Ca2(+)-dependent proteases their inhibitor in studies designed to quantify activity comparative purposes. Ion-exchange (DEAE-Sephacel) proved superior hydrophobic (Phenyl-Sepharose). Under the proper conditions, DEAE-Sephacel effectively separated low-calcium-requiring form protease (CDP-I) CDP inhibitor. Characterization assay system components proteolytic by indicated that degradation casein was linear with time up 60 min at 25 degrees C it .4 .45 units activity. Therefore, we recommend that, after identification fractions containing (CDP-I or CDP-II), these be pooled, reassayed a volume yields values less than Unlike CDP-I CDP-II, lost its rapidly frozen storage (frozen liquid nitrogen, then stored -70 C); therefore, should assayed fresh (unfrozen) samples only.