Immunochemical, chromatographic, and milk-clotting activity measurements for quantification of milk-clotting enzymes in bovine rennets.
Monospecific rabbit antibodies were produced against bovine chymosin (rennin) and bovine pepsin A and used for quantitative measurements of these enzymes by rocket immunoelectrophoresis. Bovine pepsin B was identified and measured quantitatively in tandem crossed immunoelectrophoresis, using a polyspecific antibody preparation. Chromatographically purified chymosin B and bovine pepsins A and B were used as standards. The contents of chymosin and bovine pepsin A were also determined by 2 forms of DEAE chromatography, and by an assay utilizing the ratio of milk-clotting activity at pH 6-0 and 6-5. Results obtained by measurements on 3 bovine rennets (calf rennet, adult bovine rennet, and a mixture of such types) by the different methods of analysis were in good agreement. The advantages of the immunochemical methods are direct and simultaneous identification and quantitation of enzymes.
D000367:Age Factors; D000818:Animals; D002417:Cattle; D002848:Chromatography, DEAE-Cellulose; D012085:Chymosin / Q000032:analysis*; D005069:Evaluation Studies as Topic; D007122:Immunoelectrophoresis; D007123:Immunoelectrophoresis, Two-Dimensional; D008892:Milk / Q000201:enzymology*; D010434:Pepsin A / Q000032:analysis*; D010435:Pepsinogens / Q000378:metabolism
D010435:Pepsinogens; D010434:Pepsin A; D012085:Chymosin