title: Byssochlamyopeptidase A, a rennin-like enzyme produced by Byssochlamys fulva.
abstract: The production of a rennin-like enzyme by Byssochlamys fulva varied considerably with the isolates tested. Among the seven isolates tested, NRRL 2260, IMI 83277, and N.Y. 1 were good enzyme producers. The enzyme produced by isolate IMI 83277 was purified approximately 20-fold after (NH(4))(2)SO(4) precipitation, diethylaminoethyl-cellulose chromatography and Sephadex G-100 gel filtration. The partially purified enzyme has a pH optimum at 2.9 and a temperature optimum around 60 C. The enzyme appeared to be relatively stable at 40 C between pH 3.0 and pH 6.85. A name, byssochlamyopeptidase A, was proposed for this new enzyme. The milk-clotting activity of byssochlamyo-peptidase A is dependent on pH and appeared to be minimal at pH 6.2 or above. No extensive proteolysis has been observed during the milk-clotting process. The non-trichloroacetic acid-precipitable nitrogen titration curve on skim milk was comparable to that catalyzed by animal rennet.
mesh_terms: D000645:Ammonium Sulfate; D001203:Ascomycota / Q000201:enzymology* / Q000254:growth & development / Q000302:isolation & purification; D002364:Caseins / Q000378:metabolism; D011232:Chemical Precipitation; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D003470:Culture Media; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008894:Milk Proteins / Q000378:metabolism; D009584:Nitrogen / Q000096:biosynthesis; D010447:Peptide Hydrolases / Q000096:biosynthesis* / Q000302:isolation & purification / Q000378:metabolism; D013045:Species Specificity; D013696:Temperature
chemical_list: D002364:Caseins; D003470:Culture Media; D008894:Milk Proteins; D010447:Peptide Hydrolases; D009584:Nitrogen; D000645:Ammonium Sulfate