Characterization of wine rennet and its kinetics by gel electrophoresis

Homogeneity of wine rennet examined by SDS-PAGE (15%). Lane 1=protein molecular weight markers; lane 2=native enzyme; lane 3=denatured enzyme.

Deglycosylation test of wine rennet. Lane 1=untreated rennet; lane 2=treated with peptide-N-glycosidase F; lane 3=treated with o-glycosidase.

Analysis of wine protease digest from oxidized insulin B chain by HPLC-mass spectrometry; A) HPLC analysis, where a to h indicate HPLC fractions; B) mass spectrometry analysis.

Summary of the specificity of the rennet-like protease from rice wine and compared with other sources on the oxidized insulin B chain at pH 6.5 and 37°C. Wine=the rennet-like enzyme from glutinous rice wine; Calf=calf chymosin; Mucor=aspartic protease from Mucor miehei; Rhizopus=aspartic protease from Rhizopus chinensis (Athaudaa and Takahashia, 2002).

Urea-SDS/PAGE patterns of bovine casein digestion by different rennets at 40°C and pH 6.5. Mk=molecular weight standard; α_S, β, κ=α_S1-, β-, and κ-casein; w=wine rennet; c=chymosin; m=Mucor rennet; α₁, β₁, and κ₁=the products derived from α_S1-, β-, and κ-casein.

Lineweaver-Burk plots for the cleavage of κ-casein (A), α_S1-casein (B), and β-casein (C) by wine, calf, and Mucor rennets at pH 6.5 and 40°C. υ = initial rate; [S]=substrate concentration.