Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Interaction between secretory leucocyte proteinase inhibitor and bronchial mucins or glycopeptides. Physiopathological implications for the protection of mucins against proteolysis by human leucocyte elastase.

ABSTRACT: The interaction of secretory leucocyte proteinase inhibitor with bronchial mucins and glycopeptides was studied by means of c.d. spectroscopy. The interaction with mucins was characterized by an increase in organized structure of alpha-helical type, as evidenced by the appearance in the difference spectra of two positive bands at 208 and 218 nm. This phenomenon was correlated with the amount of inhibitor present in the mixtures, suggesting that the change was inherent to the inhibitor. Surprisingly, when the inhibitor was mixed with acid glycopeptides, difference c.d. spectra showed a decrease in organized structure, characterized by a negative minimum at 196 nm. Glycopeptides treated with neuraminidase gave similar profiles of difference spectra in three different mixtures, indicating that the interaction was smaller. The interaction between the inhibitor and mucins was also studied for its ability to modify in vitro the proteolytic activity of human leucocyte elastase. Mucins alone were degraded by that proteinase into glycopeptides of Mr 400,000-500,000, whereas mucins mixed with inhibitor before adding elastase were proteolysed to a lesser extent. These data demonstrate that the secretory leucocyte proteinase inhibitor interacts with mucins and consequently is capable of protecting the mucins against proteolysis by elastase.

SUBMITTER: Van-Seuningen I

PROVIDER: S-EPMC1130756 | biostudies-other | 1992 Feb

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Influence of elastin on the inhibition of leucocyte elastase by alpha 1-proteinase inhibitor and bronchial inhibitor. Potent inhibition of elastin-bound elastase by bronchial inhibitor.

Project description:We have investigated the effect of human lung elastin on the inhibition of human leucocyte elastase by human alpha 1-proteinase inhibitor and bronchial inhibitor. Elastin was unable to dissociate the elastase-inhibitor complexes during the 150 min of the elastolysis reaction. When elastase was added to mixtures of elastin and alpha 1-proteinase inhibitor, it was fully bound to the latter. The competition between elastin and bronchial inhibitor was also in favour of the latter, but a 1.5 molar excess of inhibitor over elastase was required to achieve total binding of the enzyme. About 25% of elastin-bound elastase was found to be resistant to the inhibitory effect of alpha 1-proteinase inhibitor. The major isoenzyme and the mixture of the three minor isoenzymes of elastase exhibited similar behaviour. By contrast, bronchial inhibitor was as efficient in inhibiting the elastin-bound elastase as it was in inhibiting the free enzyme. This inhibitor was also able to inhibit fully the fraction of elastin-bound elastase that was resistant to alpha 1-proteinase inhibitor. We also describe a rapid procedure for the isolation of gram quantities of alpha 1-proteinase inhibitor.

| S-EPMC1147125 | biostudies-other

Human bronchial leucocyte proteinase inhibitor. Rapid isolation and kinetic analysis with human leucocyte proteinases.

Project description:Bronchial leucocyte proteinase inhibitor (BLPI) is an 11 000 Mr protein found in human mucous secretions. This inhibitor apparently controls the serine proteinases elastase and cathepsin G, released from extravascular polymorphonuclear leucocytes. A simple, single-step chromatographic procedure for the isolation of BLPI based on its affinity for chymotrypsin was developed. The purified inhibitor was homogeneous by electrophoresis and gel filtration. Amino acid analyses were in close agreement with previous reports, and showed BLPI to be rich in proline and cystine, but lacking histidine. We have further characterized the role of BLPI with respect to human leucocyte elastase and cathepsin G by close examination of the kinetic parameters. Additionally, we have determined the kinetics of association (kon) and dissociation (koff) for BLPI with bovine trypsin and chymotrypsin. Equilibrium dissociation constants (Ki) of 1.87 X 10(-10) M, 4.18 X 10(-9) M, 8.28 X 10(-9) M and 2.63 X 10(-8) M were obtained for human leucocyte elastase, cathepsin G, bovine trypsin and chymotrypsin, respectively. These results are discussed with respect to BLPI's possible function in vivo and its role relative to other inhibitors in bronchial secretions.

| S-EPMC1144612 | biostudies-other

Neutrophil elastase reduces secretion of secretory leukoproteinase inhibitor (SLPI) by lung epithelial cells: role of charge of the proteinase-inhibitor complex.

Project description:BackgroundSecretory leukoproteinase inhibitor (SLPI) is an important inhibitor of neutrophil elastase (NE), a proteinase implicated in the pathogenesis of lung diseases such as COPD. SLPI also has antimicrobial and anti-inflammatory properties, but the concentration of SLPI in lung secretions in COPD varies inversely with infection and the concentration of NE. A fall in SLPI concentration is also seen in culture supernatants of respiratory cells exposed to NE, for unknown reasons. We investigated the hypothesis that SLPI complexed with NE associates with cell membranes in vitro.MethodsRespiratory epithelial cells were cultured in the presence of SLPI, varying doses of proteinases over time, and in different experimental conditions. The likely predicted charge of the complex between SLPI and proteinases was assessed by theoretical molecular modelling.ResultsWe observed a rapid, linear decrease in SLPI concentration in culture supernatants with increasing concentration of NE and cathepsin G, but not with other serine proteinases. The effect of NE was inhibited fully by a synthetic NE inhibitor only when added at the same time as NE. Direct contact between NE and SLPI was required for a fall in SLPI concentration. Passive binding to cell culture plate materials was able to remove a substantial amount of SLPI both with and without NE. Theoretical molecular modelling of the structure of SLPI in complex with various proteinases showed a greater positive charge for the complex with NE and cathepsin G than for other proteinases, such as trypsin and mast cell tryptase, that also bind SLPI but without reducing its concentration.ConclusionThese data suggest that NE-mediated decrease in SLPI is a passive, charge-dependent phenomenon in vitro, which may correlate with changes observed in vivo.

| S-EPMC2529288 | biostudies-literature

Electron-Based Dissociation Is Needed for O-Glycopeptides Derived from OpeRATOR Proteolysis.

Project description:The recently described O-glycoprotease OpeRATOR presents exciting opportunities for O-glycoproteomics. This bacterial enzyme purified from Akkermansia muciniphila cleaves N-terminally to serine and threonine residues that are modified with (preferably asialylated) O-glycans. This provides orthogonal cleavage relative to canonical proteases (e.g., trypsin) for improved O-glycopeptide characterization with tandem mass spectrometry (MS/MS). O-glycopeptides with a modified N-terminal residue, such as those generated by OpeRATOR, present several potential benefits, perhaps the most notable being de facto O-glycosite localization without the need of glycan-retaining fragments in MS/MS spectra. Indeed, O-glycopeptides modified exclusively at the N-terminus would enable O-glycoproteomic methods to rely solely on collision-based fragmentation rather than electron-driven dissociation because glycan-retaining peptide fragments would not be required for localization. The caveat is that modified peptides would need to reliably contain only a single O-glycosite. Here, we use methods that combine collision- and electron-based fragmentation to characterize the number of O-glycosites that are present in O-glycopeptides derived from the OpeRATOR digestion of four known O-glycoproteins. Our data show that over 50% of O-glycopeptides in our sample generated from combined digestion using OpeRATOR and trypsin contain multiple O-glycosites, indicating that collision-based fragmentation alone is not sufficient. Electron-based dissociation methods are necessary to capture the O-glycopeptide diversity present in OpeRATOR digestions.

| S-EPMC8329938 | biostudies-literature

Investigating Polypharmacology through Targeting Known Human Neutrophil Elastase Inhibitors to Proteinase 3.

Project description:Using a combination of multisite λ-dynamics (MSλD) together with in vitro IC50 assays, we evaluated the polypharmacological potential of a scaffold currently in clinical trials for inhibition of human neutrophil elastase (HNE), targeting cardiopulmonary disease, for efficacious inhibition of Proteinase 3 (PR3), a related neutrophil serine proteinase. The affinities we observe suggest that the dihydropyrimidinone scaffold can serve as a suitable starting point for the establishment of polypharmacologically targeting both enzymes and enhancing the potential for treatments addressing diseases like chronic obstructive pulmonary disease.

| S-EPMC10865350 | biostudies-literature

Inhibition of leucocyte elastase by heparin and its derivatives.

Project description:Leucocyte proteinases, e.g. leucocyte elastase and cathepsin G, are inhibited by heparin. The activities of pig pancreatic and Pseudomonas aeruginosa elastases are unaffected by this polysaccharide. Heparin derivatives of known Mr and degree of sulphation were isolated. The inhibition of leucocyte elastase by these oligosaccharides can be classified as tight-binding hyperbolic non-competitive. Ki values ranged from 40 nM to 100 microM and were found to be inversely correlated with the chain length of the oligosaccharides. Desulphated compounds lacked inhibitory potential towards leucocyte elastase. Over-O-sulphated di- and tetra-saccharides are more potent inhibitors than their over-N-sulphated counterparts. It is proposed that the therapeutic use of heparin and its derivatives could be extended to disease states such as emphysema and rheumatoid arthritis, where the role of leucocyte elastase has been clearly established.

| S-EPMC1149174 | biostudies-other

Localization of Secretory Mucins MUC5AC and MUC5B in Normal/Healthy Human Airways.

Project description:RationaleMUC5AC and MUC5B are the predominant gel-forming mucins in the mucus layer of human airways. Each mucin has distinct functions and site-specific expression. However, the regional distribution of expression and cell types that secrete each mucin in normal/healthy human airways are not fully understood.ObjectivesTo characterize the regional distribution of MUC5B and MUC5AC in normal/healthy human airways and assess which cell types produce these mucins, referenced to the club cell secretory protein (CCSP).MethodsMultiple airway regions from 16 nonsmoker lungs without a history of lung disease were studied. MUC5AC, MUC5B, and CCSP expression/colocalization were assessed by RNA in situ hybridization and immunohistochemistry in five lungs with histologically healthy airways. Droplet digital PCR and cell cultures were performed for absolute quantification of MUC5AC/5B ratios and protein secretion, respectively.Measurements and main resultsSubmucosal glands expressed MUC5B, but not MUC5AC. However, MUC5B was also extensively expressed in superficial epithelia throughout the airways except for the terminal bronchioles. Morphometric calculations revealed that the distal airway superficial epithelium was the predominant site for MUC5B expression, whereas MUC5AC expression was concentrated in proximal, cartilaginous airways. RNA in situ hybridization revealed MUC5AC and MUC5B were colocalized with CCSP-positive secretory cells in proximal superficial epithelia, whereas MUC5B and CCSP-copositive cells dominated distal regions.ConclusionsIn normal/healthy human airways, MUC5B is the dominant secretory mucin in the superficial epithelium and glands, with distal airways being a major site of expression. MUC5B and MUC5AC expression is a property of CCSP-positive secretory cells in superficial airway epithelia.

| S-EPMC6423099 | biostudies-literature

Neutrophil elastase acts as a biased agonist for proteinase-activated receptor-2 (PAR2).

Project description:Human neutrophil proteinases (elastase, proteinase-3, and cathepsin-G) are released at sites of acute inflammation. We hypothesized that these inflammation-associated proteinases can affect cell signaling by targeting proteinase-activated receptor-2 (PAR(2)). The PAR family of G protein-coupled receptors is triggered by a unique mechanism involving the proteolytic unmasking of an N-terminal self-activating tethered ligand (TL). Proteinases can either activate PAR signaling by unmasking the TL sequence or disarm the receptor for subsequent enzyme activation by cleaving downstream from the TL sequence. We found that none of neutrophil elastase, cathepsin-G, and proteinase-3 can activate G(q)-coupled PAR(2) calcium signaling; but all of these proteinases can disarm PAR(2), releasing the N-terminal TL sequence, thereby preventing G(q)-coupled PAR(2) signaling by trypsin. Interestingly, elastase (but neither cathepsin-G nor proteinase-3) causes a TL-independent PAR(2)-mediated activation of MAPK that, unlike the canonical trypsin activation, does not involve either receptor internalization or recruitment of ?-arrestin. Cleavage of synthetic peptides derived from the extracellular N terminus of PAR(2), downstream of the TL sequence, demonstrated distinct proteolytic sites for all three neutrophil-derived enzymes. We conclude that in inflammation, neutrophil proteinases can modulate PAR(2) signaling by preventing/disarming the G(q)/calcium signal pathway and, via elastase, can selectively activate the p44/42 MAPK pathway. Our data illustrate a new mode of PAR regulation that involves biased PAR(2) signaling by neutrophil elastase and a disarming/silencing effect of cathepsin-G and proteinase-3.

| S-EPMC3137039 | biostudies-literature

Proteinase-activated receptor-1 mediates elastase-induced apoptosis of human lung epithelial cells.

Project description:Apoptosis of distal lung epithelial cells plays a pivotal role in the pathogenesis of acute lung injury. In this context, proteinases, either circulating or leukocyte-derived, may contribute to epithelial apoptosis and lung injury. We hypothesized that apoptosis of lung epithelial cells induced by leukocyte elastase is mediated via the proteinase activated receptor (PAR)-1. Leukocyte elastase, thrombin, and PAR-1-activating peptide, but not the control peptide, induced apoptosis in human airway and alveolar epithelial cells as assessed by increases in cytoplasmic histone-associated DNA fragments and TUNEL staining. These effects were largely prevented by a specific PAR-1 antagonist and by short interfering RNA directed against PAR-1. To ascertain the mechanism of epithelial apoptosis, we determined that PAR-1AP, thrombin, and leukocyte elastase dissipated mitochondrial membrane potential, induced translocation of cytochrome c to the cytosol, enhanced cleavage of caspase-9 and caspase-3, and led to JNK activation and Akt inhibition. In concert, these observations provide strong evidence that leukocyte elastase mediates apoptosis of human lung epithelial cells through PAR-1-dependent modulation of the intrinsic apoptotic pathway via alterations in mitochondrial permeability and by modulation of JNK and Akt.

| S-EPMC2715314 | biostudies-literature

Proteinase 3 and neutrophil elastase enhance inflammation in mice by inactivating antiinflammatory progranulin.

Project description:Neutrophil granulocytes form the body's first line of antibacterial defense, but they also contribute to tissue injury and noninfectious, chronic inflammation. Proteinase 3 (PR3) and neutrophil elastase (NE) are 2 abundant neutrophil serine proteases implicated in antimicrobial defense with overlapping and potentially redundant substrate specificity. Here, we unraveled a cooperative role for PR3 and NE in neutrophil activation and noninfectious inflammation in vivo, which we believe to be novel. Mice lacking both PR3 and NE demonstrated strongly diminished immune complex-mediated (IC-mediated) neutrophil infiltration in vivo as well as reduced activation of isolated neutrophils by ICs in vitro. In contrast, in mice lacking just NE, neutrophil recruitment to ICs was only marginally impaired. The defects in mice lacking both PR3 and NE were directly linked to the accumulation of antiinflammatory progranulin (PGRN). Both PR3 and NE cleaved PGRN in vitro and during neutrophil activation and inflammation in vivo. Local administration of recombinant PGRN potently inhibited neutrophilic inflammation in vivo, demonstrating that PGRN represents a crucial inflammation-suppressing mediator. We conclude that PR3 and NE enhance neutrophil-dependent inflammation by eliminating the local antiinflammatory activity of PGRN. Our results support the use of serine protease inhibitors as antiinflammatory agents.

| S-EPMC2430496 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data