Bovine pepsin

By adding 1-alkanols to AOT-based w/o microemulsions, some proteins (ribonucle-ase, lysozyme, alpha-chymotrypsin, pepsin, bovine serum albumin, and catalase) are readily expelled, while the major part of the surfactant remained in solution [171]. 

Figure 2. Logarithm of surface viscosity as a function of surface pressure for several proteins and one polyamino acid at pH 5.5. o, poly-DL-alanine , human y-globulin o, pepsin , bovine serum albumin A, lysozyme. (Reproduced with permission from Ref. 6. Copyright 1970 Marcel Dekker).

Several proteases from animal organs have been investigated for their milk-clotting potential, but only chymosin, porcine pepsin, and bovine pepsin are of interest to the cheese industry. 

Linklater (1961) reported that bovine pepsin accounted for only 0 to 6% of the milk-clotting activity of commercial rennet extracts. He used porcine pepsin as a reference standard. Bovine pepsin has increased in use as a coagulant because of the practice of extracting the stomach from older calves and adult cattle. More recently, Sellers (1982) reported that 85 to 95% of the proteolytic activity of calf rennet is due to chymosin and the remainder is from bovine pepsin. Adult bovine rennets preparations may contain 55 to 60% bovine pepsin. Mixtures of calf rennet and porcine pepsin may contain 40 to 45% chymosin, 5 to 10% bovine pepsin, and 50% porcine pepsin. Mixtures of adult bovine rennet and porcine pepsin typically contain 20 to 25% chymosin, 40 to 45% bovine pepsin, and 30 to 40% porcine pepsin activity (McMahon and Brown 1985). 

Green (1972) reported that Cheddar cheese made entirely with bovine pepsin was only slightly inferior to that made with calf rennet and Fox and Walley (1971) found no significant difference between Cheddar cheese made with bovine pepsin and rennet. Fox (1969) found that the milk-clotting activity of bovine pepsin is less pH-dependent than that... 

Fox, P. F. 1969. Milk-clotting and proteolytic activities of rennet, and of bovine pepsin and porcine pepsin. J. Dairy Res. 36, 427-433. 

Green, M. L. 1972. Assessment of swine, bovine and chicken pepsins as rennet substitutes for Cheddar cheesemaking. J. Dairy Res. 39, 261-273. 

Proteolysis of casein begins with the addition of rennet to the milk and the formation of a coagulum. Calf rennet is actually 80% chymosin and 20% bovine pepsin A (Grappin et al 1985). Rennet can remain active in Cheddar and Camembert cheeses for up to three months, but... 

Schlamowitz, M. and Peterson, L.U. 1959. Studies on the optimum pH for the action of pepsin on native and denatured bovine serum albumin and bovine hemoglobin. J. Biol. Chem. 234 3137-3145. 

Pepsin Dioctylsodium sulfosuccinate, bovine uterine serpin, ovine uterine serpin, pepsinostreptin, pepstatin... 

A purified pepsin isolated from a bovine preparation was subject to an amino acid analysis of its hydrolytic products. The amino acid present in the smallest amount was lysine, C6H14N2O2, and the amount of lysine recovered was found to be 0.43 g per 100 g protein. What is the minimum molar mass of the protein ... 

In conclusion, the double mutant pepsin T77D/G78(S)S79 was also able to activate bovine trypsinogen to trypsin by the selective cleavage of the Lys6-Ile7 bond of trypsinogen. Results of this study suggest that the structure of the active site flap contribute to the Si substrate specificity for basic amino acid residues in aspartic proteinases. 

Whey proteins contain opioid-like sequences, namely a-la (both bovine and human) f(50-53) and (3-1 g (bovine) f(102-105), in their primary structure. These peptides have been termed a- and (3-lactorphins (Chiba and Yoshikawa, 1986). Studies by Antila et al (1991) indicated that proteolysis of a-la with pepsin produces a-lactorphin, and that digestion of (3-lg with... 

Bovine haemoglobin, the protein from erythrocytes which occurs as a minor component in meat and meat products, is also a precursor of opioid peptides (haemorphins). These opioid peptides are released by pepsin digestion in vitro and may also be produced by macrophages. Moreover, haemorphins have been found to decrease the tension of the guinea pig ileum in vitro (Nyberg et al., 1997). 

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