Proteolytic Activities of Chymosin and Porcine Pepsin on Buffalo, Cow, and Goat Whole and β-Casein Fractions

Abstract

The proteolytic specificity and activity of a recombinant chymosin (Maxiren) and porcine pepsin on buffalo, cow, and goat whole casein (CN) and β-CN were studied by analyzing the degradation products. The results suggest that the hydrolysis of whole casein of buffalo and goat by chymosin was similar to that of cow casein resulting in αs1-I and β-I, -II, and -III as degradation fragments of αs1- and β-CN. The exception was goat β-I which was resistant to further hydrolysis by chymosin but not to porcine pepsin at pH 5.4−6.2. Increasing NaCl concentration to ≥5% reduced the proteolysis of β-CN in all three species, but not that of αs1-CN. The fragments of β-I, -II, and -III produced from β-CN of the three species gave identical results with PAGE. αs1-I and its degradation fragments had in all three species, regardless of the different electrophoretic mobilities on PAGE, the same sequence of appearance. The results indicate that chymosin and porcine pepsin attacked in buffalo and goat caseins the same regions as known for cow αs1- and β-CN. Keywords: Proteolysis; chymosin; porcine pepsin; buffalo, cow, goat caseins

Recent advances in milk clotting enzymes

“…2009). Cryphonectria parasitica protease is less characterised, but it is generally acknowledged that its total proteolytic activity is higher (Tam and Whitaker 1972; Vanderporten and Weckx 1972) and that, in contrast to protease from Rhizomucor , mainly β‐casein is hydrolysed (Ustunol and Zeckzer 1996; Awad et al. 1998, 1999; Trujillo et al.…”

Proteolysis in Turkish White-brined cheese made with defined strains of Lactococcus

“…This may have an effect on the hydrolysis of caseins. Increasing of NaCl concentration (from X5% to 10%) reduced the proteolysis of b-casein in casein solutions (Awad, Luthi-Peng, & Puhan, 1998); the hydrolysis of a s1 -casein was not inhibited by the high NaCl concentration (e.g., 10%) (Awad, Luthi-Peng, & Puhan, 1999a). Starter proteinases have contributed to a small extent to the initial degradation of b-casein (Awad, Luthi-Peng, & Puhan, 1999b).…”

Proteolytic properties of Turkish white‐brined cheese (Beyaz peynir) made by using wild‐type Lactococcal strains

“…Therefore, the electrophoretic differences between the samples regarding a s1 -CN degradation products could be attributed to the differences in the peptidases and ⁄ or aminopeptidases activities of the strains used. It was reported that the hydrolysis of a s -CN was not completely inhibited by NaCl concentration (Awad et al 1998). In all samples, the bands representing c 1 -CN (b-CN f29-209), c 2 -CN (b-CN f106-209) and c 3 -CN (b-CN f108-209) became evident, being slightly fader in the cheese MBLL23.…”

“…Therefore, the electrophoretic differences between the samples regarding α s1 ‐CN degradation products could be attributed to the differences in the peptidases and/or aminopeptidases activities of the strains used. It was reported that the hydrolysis of α s ‐CN was not completely inhibited by NaCl concentration (Awad et al. 1998).…”