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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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Journal ArticleDOI
TL;DR: In this article, the in vitro biodegradation of Bombyx mori silk fibroin was studied by incubating fibers and films with proteolytic enzymes (collagenase type F, α-chymotrypsin type I-S, protease type XXI), for times ranging from 1 to 17 days.
Abstract: The in vitro biodegradation of Bombyx mori silk fibroin was studied by incubating fibers and films with proteolytic enzymes (collagenase type F, α-chymotrypsin type I-S, protease type XXI), for times ranging from 1 to 17 days The changes in sample weight and degree of polymerization of silk fibers exposed to proteolytic attack were negligible However, tensile properties were significantly affected, as shown by the drop of strength and elongation as a function of the degradation time Upon incubation with proteolytic enzymes, silk films exhibited a noticeable decrease of sample weight and degree of polymerization, the extent of which depended on the type of enzyme, on the enzyme-to-substrate ratio, and on the degradation time Protease was more aggressive than α-chymotrypsin or collagenase Film fragments resistant to enzymatic degradation were enriched in glycine and alanine FT-IR measurements showed that the degree of crystallinity of biodegraded films increased Soluble degradation products of silk films consisted of a range of peptides widely differing in size, deriving from the amorphous sequences of the silk fibroin chains Biodegraded fibers showed an increase of surface roughness, while films displayed surface cracks and cavities with internal voids separated by fiber-like elements

320 citations

Journal ArticleDOI
TL;DR: Thyroid hormone-activated mitochondrial mechanisms provide protection against excessive tissue dysfunction, including increased expression of uncoupling proteins, proteolytic enzymes and transcriptional coactivator PGC-1, and stimulate opening of permeability transition pores.
Abstract: Hypermetabolic state in hyperthyroidism is associated with tissue oxidative injury. Available data indicate that hyperthyroid tissues exhibit an increased ROS and RNS production. The increased mitochondrial ROS generation is a side effect of the enhanced level of electron carriers, by which hyperthyroid tissues increase their metabolic capacity. Investigations of antioxidant defence system have returned controversial results. Moreover, other thyroid hormone-linked biochemical changes increase tissue susceptibility to oxidative challenge, which exacerbates the injury and dysfunction they suffer under stressful conditions. Mitochondria, as a primary target for oxidative stress, might account for hyperthyroidism linked tissue dysfunction. This is consistent with the inverse relationship found between functional recovery of ischemic hyperthyroid hearts and mitochondrial oxidative damage and respiration impairment. However, thyroid hormone-activated mitochondrial mechanisms provide protection against excessive tissue dysfunction, including increased expression of uncoupling proteins, proteolytic enzymes and transcriptional coactivator PGC-1, and stimulate opening of permeability transition pores.

320 citations

Journal ArticleDOI
TL;DR: exciting recent developments on the role of inflammasome complexes in host defense and the discovery of a new DNA sensing inflammaome are reviewed and important progress made are described in the understanding of howinflammasomes are activated.

320 citations

Journal ArticleDOI
TL;DR: A highly purified glycopeptide with potent phytohemagglutinin (PHA) receptor site activity has been isolated from human erythrocyte membranes, showing that the inner core sugars can influence PHA-inhibitory activity.

319 citations

Journal ArticleDOI
TL;DR: In this article, the genes of chlamydia trachomatis were cloned and epitope-mapped with a panel of monoclonal antibodies (mAbs).
Abstract: Chlamydia trachomatis is an obligate prokaryotic intracellular pathogen of humans that infects mucosal epithelial cells. Exposed domains of its major outer membrane protein (MOMP) are both serotyping and protective antigenic determinants. To identify these domains, we have cloned and epitope-mapped the genes of serovars A, C (C serogroup) and L2, B (B serogroup) with a panel of monoclonal antibodies (mAbs). Predominantly conserved regions of the genes of both serogroups are interspersed with four short variable domains (I-IV). Recombinant phage clones expressing specific MOMP antigenic determinants revealed that protective serotype-specific recognized epitopes in variable domains I and II. Protective subspecies and serogroup-specific mAbs recognized overlapping determinants in variable domain IV near the C terminus. A nonprotective species-specific mAb mapped to an invariant peptide of nine residues contained within variable domain IV. In the intact chlamydial organism of serovar B, variable domains II and IV were susceptible to proteolytic digestion, whereas both N and C termini were protected. These results suggest an arrangement of MOMP in the outer membrane in which three of the four variable domains are exposed to the outside and in which both N and C termini are presumably oriented toward the periplasmic space. This molecular analysis of MOMP antigenic determinants and their surface topology on intact chlamydiae will be useful toward the development of a recombinant subunit or synthetic chlamydial vaccine.

318 citations


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