Porcine pepsin A and bovine chymosin are typical models of aspartic proteinases. The hydrolytic specificities of these proteinases, along with those of human pepsin A and monkey chymosin, were investigated with 29 peptide substrates that included various P1' variants of seven parent peptides. From these peptides, AFPLEF downward arrow FREL was preferred by pepsin A and chymosin, while its P1' variant, AFPLEF downward arrow EREL was preferred by bovine chymosin. Porcine and human pepsin A showed similar hydrolytic specificities, strongly preferring a hydrophobic/aromatic residue at P1' of any type of peptide. This specificity is well explained by the very hydrophobic nature of the S1' subsite that consists of Tyr(189), Ile(213), Ile(300), Met(289), Val/Leu(291) and Leu(298). The first three residues are well conserved in pepsin family enzymes. Although bovine and monkey chymosin showed similar P1' specificity, bovine chymosin preferred peptides having Glu at P1', while monkey chymosin preferred peptides having Lys at P1'. The dual characteristics of chymosin are due to the occurrence of polar/charged residues in the S1' subsite, such as Glu/Asp(289), Gln(298) and Lys/Gln(299), which are different from the S1' subsite of pepsin A. Molecular models suggest that Glu in position 289 of bovine chymosin and Asp in position 289 of monkey chymosin are responsible for the difference in P1' specificities between the chymosins.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1093/jb/mvp158 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The combined effect of the gene copy number and chaperone overexpression on the recombinant bovine chymosin production in Pichia pastoris, with mutant ADH2 promoter.
Protein Expr Purif
March 2025
Akdeniz University, Engineering Faculty, Department of Food Engineering, Turkiye; İzmir Biomedicine and Genome Center, Turkiye.
Chymosin is an enzyme used to coagulate milk, in the cheese industry. This study aimed to increase recombinant production of the chymosin in Pichia pastoris by determining the optimum copy number and overproduction of a Protein Disulfide Isomerase (PpPDI) chaperon protein. Bos taurus chymosin was expressed under the control of a mutant ADH2 promoter.
View Article and Find Full Text PDFImpact of ultrasonic and heat treatments on the physicochemical properties and rennet-induced coagulation characteristics of milk from various species.
Ultrason Sonochem
December 2024
College of Food Science and Engineering, Qingdao Agricultural University, Qingdao 266109, Shandong, China; Bathurst Future Agri-Tech Institute, Qingdao Agricultural University, Qingdao 266109, Shandong, China. Electronic address:
This study investigates the effects of heat and ultrasonic treatments on the physicochemical parameters and rennet-induced coagulation properties of milk from a variety of species, including cow, goat, buffalo, and donkey. Milk samples were subjected to heat treatments at different temperatures (65 °C, 80 °C, 90 °C, 100 °C) and ultrasonic treatment at varying power levels (200 W, 400 W, 600 W, 800 W, 1000 W). The results revealed that changes in turbidity, particle size, zeta potential, secondary structure, and surface hydrophobicity were altered by both ultrasonic and heat treatments, as well as the kind of milk.
View Article and Find Full Text PDFComparative analysis of the quality of buffalo milk fresh cheese processed with Moringa oleifera seed milk coagulant and calf rennet.
J Dairy Sci
December 2024
College of Food Science and Technology, Yunnan Agricultural University, Kunming 650201, Yunnan, China. Electronic address:
This study aimed to evaluate the impact of using Moringa oleifera seed milk coagulant and calf rennet to produce buffalo milk fresh cheese. No significant difference was found between composition and functional characteristics. M.
View Article and Find Full Text PDF[Construction of a strain with multi-copy integration for enhanced bovine chymosin production by CRISPR/Cas9 and UV mutagenesis].
Sheng Wu Gong Cheng Xue Bao
September 2024
School of Biotechnology, Jiangnan University, Wuxi 214122, Jiangsu, China.
Bovine chymosin is an essential food enzyme widely used in cheese production in the dairy industry. This study used a codon-optimized prochymosin gene to construct an expression cassette for extracellular expression of bovine chymosin in . After integration of the prochymosin gene into the host cell genome, the single-copy integration strain KLUcym showed the clotting activity of 40 U/mL in a shake flask.
View Article and Find Full Text PDFRennets differing in chymosin-to-pepsin ratio shape the metabolomic and sensory profile of Grana Padano PDO cheese during ripening.
Food Res Int
November 2024
Department for Sustainable Food Process, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy.
Article Synopsis
- - This study explored how different ratios of chymosin and pepsin in rennet affect the sensory profile of Grana Padano PDO cheese over a ripening period of 10 to 20 months.
- - Results indicated that a rennet composition of 83% chymosin and 17% pepsin led to a more complex sensory profile after 12 months of aging, highlighting the significance of enzyme selection in cheesemaking.
- - Analysis revealed that ripening time was a crucial factor affecting cheese characteristics, with specific compounds like 3-methylbutanoic acid and homoethone increasing in cheeses made with higher pepsin percentages, influencing the sensory experience.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!