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A FLUOROMETRIC ASSAY FOR PROTEINASE A IN BEER AND ITS APPLICATION FOR THE INVESTIGATION OF ENZYMATIC EFFECTS ON FOAM STABILITY
Author(s) -
Yokoi Shigehisa,
Shigyo Tatsuro,
Tamaki Teruo
Publication year - 1996
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1996.tb00892.x
Subject(s) - chemistry , chromatography , yeast , proteinase k , substrate (aquarium) , pasteurization , enzyme , biochemistry , biology , ecology
A previously developed fluorometric assay using synthetic substrate, Succinyl‐Arg‐Pro‐Phe‐His‐Leu‐Leu‐Val‐Tyr‐4‐methylcoumaryl‐7‐amide, for yeast proteinase A (PrA) was modified for the accurate and quick determination for the activity in unpasteurized beer. Employing simple HPLC for the determination of 7‐amino‐4‐methylcoumarine (AMC), a final degradation product on this assay, the activity of PrA in beer was measured without the interference of the fluorogenic and photosensitive substance present in beer. The assay for common unpasteurized beers was completed within 5 hours without any concentration procedure. Its linearity and reproducibility were satisfactory for quantitative purposes. Using a purified PrA from brewer's yeast, the effect of the PrA activity on foam stability during storage was furthermore clarified. The exclusive effect of PrA on foam stability was also demonstrated by proteinase inhibitor test.