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Proteolytic enzymes

About: Proteolytic enzymes is a research topic. Over the lifetime, 23096 publications have been published within this topic receiving 835544 citations.


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TL;DR: The polypeptide compositions of single- shelled and double-shelled simian rotavirus particles were modified by exposure to proteolytic enzymes, and the role of cleavage activation in other virus-specific biological functions (e.g., hemagglutination and virulence).
Abstract: The polypeptide compositions of single-shelled and double-shelled simian rotavirus particles were modified by exposure to proteolytic enzymes. Specifically, a major outer capsid polypeptide (VP3) having a molecular weight of 88,000 in double-shelled particles was cleaved by trypsin to yield two polypeptides, VP5* and VP8* (molecular weights, 60,000 and 28,000, respectively). The cleavage of VP3 by enzymes that enhanced infectivity (trypsin, elastase, and pancreatin) yielded different products compared to those detected when VP3 was cleaved by chymotrypsin, which did not enhance infectivity. The appearance of VP5* was correlated with an enhancement of infectivity. Cleavages of the major internal capsid polypeptide VP2 were also observed. The VP2 cleavage products had molecular weights similar to those of known structural and nonstructural rotavirus polypeptides. We confirmed the precursor-product relationships by comparing the peptide maps of the polypeptides generated by digestions with V-8 protease and chymotrypsin. The remaining rotavirus structural polypeptides, including the outer capsid glycoproteins (VP7 and 7a), were not altered by exposure to pancreatic enzymes. Cleavage of VP3 was not required for virus assembly, and specific cleavage of the polypeptides occurred only on assembled particles. We also discuss the role of cleavage activation in other virus-specific biological functions (e.g., hemagglutination and virulence).

366 citations

Journal Article
TL;DR: Most VIC in normal valves were quiescent with a fibroblast-like phenotype, with sparse alpha-SMA expression, followed by a normalization of phenotype.
Abstract: Background and aim of the study: The roles of cardiac valvular interstitial cells (VIC) in extracellular matrix remodeling in fetal development, adaptation and response to injury are largely unknown. Methods: The phenotype of VIC was studied in health (normal adult human and sheep), development (fetal human and sheep), disease (human mitral valves with myxomatous degeneration), adaptation (clinical pulmonary to aortic valve autografts) and tissue-engineered heart valves matured in vitro and remodeled in vivo. Cell phenotype was assessed using expression of vimentin (V), α-smooth muscle actin (SMA, A), matrix metalloproteinase (MMP)13/collagenase-3 (M), and SMemb (S). Results: VIC in normal adult valves were predominantly quiescent fibroblasts immunoreactive to vimentin (89.7 ± 2.5%), but not MMP-13 or SMemb, with only 2.5 ± 0.4% of α-SMA-positive cells (‘normal/quiescent’ phenotype: V+/A-/M-/S-). In contrast, fetal VIC were mostly activated myofibroblasts (‘developing/activated’ phenotype: V+/A+/M+/S+), with 62.1 ± 5.0% of cells staining positive for α-SMA. VIC in myxomatous valves, short-term autografts and engineered valves in vitro were also activated myofibroblasts with coexpression of vimentin, αSMA (36.2 ± 3.7%, 19.3 ± 2.4%, and 60.3 ± 9% positive cells, respectively), strong MMP-13 activity indicative of collagen remodeling, and SMemb (‘remodeling/activated’ phenotype: V+/A+/M+/S+). In contrast, VIC in long-term pulmonary autografts and engineered valve explants had a mostly fibroblast-like phenotype, with sparse α-SMA expression (6.0 ± 1% and 5.4 ± 1.0% positive cells) (V+/A-/M-/S-). Conclusion: Most VIC in normal valves were quiescent with a fibroblast-like phenotype. VIC in developing, diseased, adapting and engineered valves adjust to a dynamic environment through VIC activation and secretion of proteolytic enzymes mediating extracellular matrix remodeling (‘developing/ remodeling/activated’ phenotype), followed by a normalization of phenotype.

365 citations

Journal ArticleDOI
TL;DR: Fourteen bacteriocin-producing strains from the genera Lactobacillus, Leuconostoc, Pediococcus, and Lactococcus were evaluated for their ability to inhibit the growth of eight strains of Listeria monocytogenes.

365 citations

Journal ArticleDOI
TL;DR: Data indicate that a unique receptor capable of interacting specifically with apo-E-containing lipoproteins, and not with apO-B-containinglipoprotein (LDL), exists in the adult canine liver.

364 citations

Journal ArticleDOI
TL;DR: Cathepsin B, and potentially other proteases, may serve as a biomarker for vulnerable plaques when probed with beacons and the tomographic in vivo imaging method could be readily adapted to screening and potentially to the molecular profiling of a number of proteases in vulnerable plaque in vivo.
Abstract: Background— Atherosclerotic plaque rupture, the most important cause of acute cardiovascular incidents, has been strongly associated with vascular inflammation. On the basis of the hypothesis that the inflammatory response and proteolysis lead to plaque rupture, we have examined the role of cathepsin B as a model proteolytic enzyme. Methods and Results— Using western-type diet–fed apoE and apoE/endothelial NO synthase double knockout mice as models of atherosclerosis, we show (1) that cathepsin B is upregulated in atherosclerotic lesions characterized by high degrees of inflammation compared with normal aorta or silent lesions,(2) that intravenously injectable novel cathepsin B imaging beacons are highly activated within active atherosclerotic lesions and colocalize with cathepsin B immunoreactivity, and(3) that cathepsin B activity in atherosclerotic lesions can be imaged in whole animals by using a novel near-infrared tomographic imaging system. Conclusions— These studies indicate that cathepsin B, and ...

363 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202350
2022113
2021358
2020434
2019358
2018472