title: [Purification and properties of an esterase excreted during sporulation of Bacillus subtilis].
abstract: After growth in Difco Nutrient Broth, several proteolytic enzymes are excreted by B. subtilis, Marburg strain, namely a metalloprotease and a seryl protease. We report here the purification and some biochemical properties of a third extracellular hydrolytic enzyme for which we propose the term of esterase. As the serylprotease, the esterase is a seryl enzyme endowed with both proteolytic and esterolytic activities. Nevertheless the esterase differs from serylprotease in many aspects. In particular, it is an acidic enzyme with a low proteolytic activity and a high esterolytic activity. Its specificity toward synthetic substrates is restricted. The enzyme is active only on esters of amino acids and particularly on those of tyrosine. With Bz Tyr O Et as substrate the esterase displays a maximum of activity between pH 7.2 and 8.1 with a Km of 1.3.10-minus 3 M at 30 degrees C. At the end of this work, two questions remain unanswered: 1) the origin of the multiplicity of the bands revealed by polyacrylamide electrophoresis in the purest fraction; 2) the nature of the physiological substrate of the enzyme.
mesh_terms: D015082:2,2'-Dipyridyl / Q000494:pharmacology; D001391:Azo Compounds / Q000378:metabolism; D001412:Bacillus subtilis / Q000201:enzymology*; D002364:Caseins / Q000378:metabolism; D002729:Chloromercuribenzoates / Q000494:pharmacology; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D002854:Chromatography, Paper; D004492:Edetic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004950:Esterases / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007531:Isoflurophate / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000378:metabolism; D010618:Phenanthrolines / Q000494:pharmacology; D010830:Physostigmine / Q000494:pharmacology; D013171:Spores, Bacterial; D013696:Temperature; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D001391:Azo Compounds; D002364:Caseins; D002729:Chloromercuribenzoates; D010618:Phenanthrolines; D007531:Isoflurophate; D014443:Tyrosine; D015082:2,2'-Dipyridyl; D004492:Edetic Acid; D010830:Physostigmine; D004950:Esterases; D010447:Peptide Hydrolases
vernacular_title: Purification et propriétés d'une estérase excrétée pendant la sporulation de Bacillus subtilis