Agricultural and Biological Chemistry · 1967 · 10 citations · 0 references
Life SciencesBiochemistryEnzyme TechnologyEnzymologyMilk ChemistryEnzyme CharacterizationEnzyme IsolationMilk EnzymesMilk ProteinsProtein SeparationProteolytic EnzymesEnzyme Ph StabilityGel ElectrophoresisMicrobial ProteasesMilk Protein DigestionPh DependencePh StabilityPh-dependent StabilitySedimentation Analysis
A crystalline acid protease produced by a strain of Acrocylindrium in a submerged culture was prepared by treatment with acetone (60%), salting out with ammonium sulfate (saturated) and, after chromatography on Duolite CS-10l column, dialysis against distilled water. This preparation was homogeneous on sedimentation analysis, starch-gel electro-phoresis and gel filtration with Sephadex G-75. The optimum pH was 2.0 for milk casein digestion and the pH stability was for 2.0_??_5.0 at 30°C for one day. The crystalline enzyme was completely stable below 50°C, but lost the activity at 70°C in ten minutes. The acid protease was almost equal to pepsin on specific activity when milk casein solution (pH 2.0) was used as substrate.