Abstract Genetically engineered chymosin from the tree shrew ( Tupaia belangeri chinensis ) has been obtained and partially characterized for first time. The target enzyme was produced in Escherichia coli , strain BL21(DE3). It shown that recombinant coagulates cow milk Bos taurus ). total specific milk-clotting activity of 0.7–5.3 IMCU/mL 8.8–16.6 IMCU/mg. nonspecific proteolytic relation to b...

Bovine and camel chymosin are aspartic peptidases that are used industrially in cheese production. They cleave the Phe105-Met106 bond of the milk protein κ-casein, releasing its predominantly negatively charged C-terminus, which leads to the separation of the milk into curds and whey. Despite having 85% sequence identity, camel chymosin shows a 70% higher milk-clotting activity than bovine chym...

components, chymosins I and 11, by column chromatography on DEAE-cellulose (Fig. 1). The same characteristic profile was obtained from four different animals. Pooled fractions of chymosins I and I1 were examined by urea/polyacrylamide-gel electrophoresis, and each consisted of one major protein species, with chymosin I1 showing a slightly higher electrophoretic mobility than chymosin I. Chymosi...

To circumvent problems encountered in the synthesis of active chymosin in a number of bacteria and fungi, a recombinant DNA L-form expression system that directed the complete secretion of fully activable prochymosin into the extracellular culture medium was developed. The expression plasmid constructions involved the in-frame fusion of prochymosin cDNA minus codons 1 to 4 to streptococcal pyro...

Chymosin B point mutants, A115T and G243D (chymosin A), were expressed in Escherichia coli and Trichoderma reesei respectively, characterized biochemically, crystallized and studied by X-ray analysis at 2.3 and 2.8 angstroms resolutions respectively. The three-dimensional structures showed that the mutations gave rise to local conformational changes only when compared with that of chymosin B. K...

Prochymosin can be converted into chymosin by an action of external proteinases. Thus, thermolysin at pH 5.05 converts calf prochymosin into active Phe-chymosin, which is one amino acid longer than chymosin from the N-terminus with a yield of 73%. Even better results were achieved with prochymosin activation by Legionella pneumophila metalloproteinase. Apparently the stretch of prochymosin poly...

The use of agroindustrial wastes not only decreases bioprocesses and disposal costs but also contributes to the upgrading of the residues. An active recombinant methanol-inducible bovine chymosin has been expressed in our laboratory in the yeastKomagataella pastoris, and grape pomace extracts (GRE) were proposed as a convenient C-energy source for the biomass production of the genetically engin...