The three-dimensional structures of pepsin inhibitor-3 (PI-3) from Ascaris suum and of the complex between PI-3 and porcine pepsin at 1. 75 A and 2.45 A resolution, respectively, have revealed the mechanism of aspartic protease inhibition by this unique inhibitor. PI-3 has a new fold consisting of two domains, each comprising an antiparallel beta-sheet flanked by an alpha-helix. In the enzyme-inhibitor complex, the N-terminal beta-strand of PI-3 pairs with one strand of the 'active site flap' (residues 70-82) of pepsin, thus forming an eight-stranded beta-sheet that spans the two proteins. PI-3 has a novel mode of inhibition, using its N-terminal residues to occupy and therefore block the first three binding pockets in pepsin for substrate residues C-terminal to the scissile bond (S1'-S3'). The molecular structure of the pepsin-PI-3 complex suggests new avenues for the rational design of proteinaceous aspartic proteinase inhibitors.
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http://dx.doi.org/10.1038/77950 | DOI Listing |
Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
December 2024
Endoscopy Center, Peking University People's Hospital, Beijing100044, China.
To establish a novel laryngopharyngeal reflux model in Bama minipigs excluding concurrent gastroesophageal reflux through endoscopic cricopharyngeal myotomy. Twelve 8-month-old male Bama minipigs were randomly assigned to three groups: Group 1 underwent cricopharyngeal myotomy alone, Group 2 underwent combined cricopharyngeal and lower esophageal sphincter myotomy, and Group 3 served as the control group. Following a one-week acclimatization period, the respective surgical procedures were performed.
View Article and Find Full Text PDFJ Anim Sci Technol
November 2024
Department of Animal Science, Chungbuk National University, Cheongju 28644, Korea.
The objective of this study was to evaluate predictions of digestibility at each age (puppy, adult, and senior) in dogs of dry matter (DM), organic matter (OM), crude protein (CP), gross energy (GE), crude fiber (CF), and ether extract (EE) using dog diets. First, to determine the digestibility of dog diets using pepsin and pancreatin incubations, conduct the method. Later, 18 mixed-sex beagles were used in this experiment to compare digestibility.
View Article and Find Full Text PDFBiofabrication
December 2024
Department of Respiratory and Critical Care Medicine, State Key Laboratory of Respiratory Health and Multimorbidity, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, People's Republic of China.
Recent studies have shown promising results using decellularized extracellular matrix (dECM) matrikines-based hydrogel as attractive strategies for preventing and alleviating fibrosis.Porcine lung decellularization and pepsin digestion were used to prepare the lung dECM hydrogel. Proteomic analysis revealed that the lung dECM hydrogel was enriched in glycoproteins, collagens, laminins, fibrinogen, held receptors, and bound growth factors.
View Article and Find Full Text PDFJ Food Sci
September 2024
Faculty of Fisheries and Food Science, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia.
Collagens are conventionally derived from bovine and porcine sources. However, these sources were commonly associated with infectious diseases such as bovine spongiform encephalopathy, foot and mouth disease, autoimmune and allergic reactions, and religious constraints. The significant amount of collagen available in marine species, especially fish skins, scales, fins, and bones, shows that marine species can be a potential alternative source to mammalian collagen.
View Article and Find Full Text PDFFoods
July 2024
Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec City, QC G1V 0A6, Canada.
is a foodborne pathogen that represents a serious concern for ready-to-eat (RTE) meat products due to its persistence in production facilities. Among the different strategies for the control of this pathogen, the use of antimicrobial peptides derived from food by-products, such as slaughterhouse blood proteins, has emerged as a promising biocontrol strategy. This study evaluated for the first time the use of peptic hydrolysates of porcine hemoglobin as a biocontrol strategy of in RTE pork cooked ham.
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