Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Secretory leukocyte protease inhibitor (SLPI) is a 12 kD nonglycosylated serine antiproteinase secreted by cells of mucosal surfaces. In human lung, SLPI is present in the respiratory epithelium. It is the major barrier to tissue destruction mediated by the polymorphonuclear leukocyte (PMN) serine proteinases, elastase and cathepsin G, within the upper respiratory tract. We have recently described a third PMN serine proteinase, proteinase-3, that like elastase causes lung matrix destruction and experimental emphysema. The current studies examine interactions between SLPI and proteinase-3. The results show that: (1) SLPI and its reactive-site variants have no or minimal inhibitory activity against proteinase-3; (2) native SLPI does not complex with proteinase-3; (3) proteinase-3 selectively degrades both native and oxidized SLPI; (4) the cleavage of SLPI by proteinase-3 occurs at the peptide bond COOH-terminal to Ala-16 in the NH2-terminal domain of SLPI.
Am J Respir Cell Mol Biol 1993 Jun
PMID:Interaction of secretory leukocyte protease inhibitor with proteinase-3. 810 Jul 9

Hemolymph of Manduca sexta contains a number of serine proteinase inhibitors from the serpin superfamily. During formation of a stable complex between a serpin and a serine proteinase, the enzyme cleaves a specific peptide bond in an exposed loop (the reactive-site region) at the surface of the serpin. The amino acid residue on the amino-terminal side of this scissile bond, the P1 residue, is important in defining the selectivity of a serpin for inhibiting different types of serine proteinases. M. sexta serpin-1B, with alanine at the position predicted from sequence alignments to be the P1 residue, was previously named alaserpin. This alanyl residue was changed by site-directed mutagenesis to lysine (A343K) and phenylalanine (A343F). The serpin-1B cDNA and its mutants were inserted into an expression vector, H6pQE-60, and the serpin proteins were expressed in Escherichia coli. Affinity-purified recombinant serpins selectively inhibited mammalian serine proteinases: serpin-1B inhibited elastase; serpin-1B(A343K) inhibited trypsin, plasmin, and thrombin; serpin-1B(A343F) inhibited chymotrypsin as well as trypsin. All three serpins inhibited human cathepsin G. This insect serpin and its site-directed mutants associated with mammalian serine proteinases at rates similar to those reported for mammalian serpins. Serpin-1B and its mutants formed SDS-stable complexes with the enzymes they inhibited. The scissile bond was determined to be between residues 343 and 344 in wild-type serpin-1B and in serpin-1B with mutations at residue 343. These results demonstrate that the P1 alanine residue defines the primary selectivity of serpin-1B for elastase-like enzymes, and that this selectivity can be altered by mutations at this position.
Insect Biochem Mol Biol 1995 Dec
PMID:Expression and characterization of recombinant Manduca sexta serpin-1B and site-directed mutants that change its inhibitory selectivity. 858 Sep 9

Gut proteinases are involved in the solubilization and activation of insecticidal toxins produced by Bacillus thuringiensis and may also be involved in resistance development. Approximately threefold lower chymotrypsin-like enzyme activity was observed in a Bt(entomocidus)-resistant strain of the Indianmeal moth, Plodia interpunctella, than that in the Bt-susceptible strain. Because chymotrypsin-like proteinases are involved in Bt protoxin activation in P. interpunctella, we compared cDNA sequences, mRNA expression levels, and genomic DNA for chymotrypsin-like enzymes in Bt-susceptible and Bt-resistant strains of P. interpunctella. To isolate cDNA coding for chymotrypsinogen-like proteinases, a probe was developed using polymerase chain reaction (PCR) amplification of a cDNA library from the Bt-susceptible strain using a vector primer and a degenerate primer corresponding to a conserved sequence in the active site of serine proteinases. This probe was used to screen cDNA libraries from resistant and susceptible strains. Predicted amino acid sequences from cDNA clones of each strain share similarity with sequences of chymotrypsin-like proteinases and are most similar to a chymotrypsin-like proteinase from the tobacco hornworm, Manduca sexta. cDNAs for putative chymotrypsinogen-like proteins, from both Bt-susceptible and Bt-resistant strains of P. interpunctella share an identical open reading frame of 846 nucleotides. The encoded proteins contain amino acid sequence motifs of serine proteinase active sites, disulfide-bridge cysteine residues, and both zymogen activation and signal peptides. A difference between these cDNAs was observed only in the untranslated region where a substitution of guanine for adenine occurred in the Bt-resistant strain. Southern and Northern blotting analyses indicated that there are no major differences in chymotrypsinogen-like genomic organization and mRNA expression in the two strains. These data suggest that chymotrypsinogen-like proteinase genes and their transcription are similar in the Bt-susceptible and Bt-resistant strains of P. interpunctella.
Insect Biochem Mol Biol 1997 Dec
PMID:cDNAs for a chymotrypsinogen-like protein from two strains of Plodia interpunctella. 956 43

Proteolysis of the amyloid beta protein precursor (APP) is a key event in the development of Alzheimer's disease. In our search for proteases that can cleave APP and liberate the amino terminus of the amyloidogenic beta protein, we characterized a calcium-dependent serine protease (CASP) which is present in reactive astrocytes and cross-reacts with anti-cathepsin G antibodies. We wanted to take advantage of this cross-reactivity to clone the cDNA of CASP and eventually evaluate its tissue distribution. Screening of two human fetal brain cDNA libraries with anti-cathepsin G antibodies led to the identification of a cDNA coding for a novel protein whose only homology to known proteins is to the active site of trypsin-type serine proteases. We called this protein the novel serine protease (NSP). NSP exists in at least three differentially spliced forms, one of which is expressed predominantly in brain and testis. Immunohistochemistry and immunoprecipitation with antibodies generated against NSP show that it is expressed and secreted by a variety of cells and that, in brain, it is found primarily in cerebrovascular smooth muscle cells and reactive astrocytes.
Brain Res Mol Brain Res 1998 Apr
PMID:Identification of a novel serine protease-like molecule in human brain. 958 21

The beige mouse is currently used as a model of elastase and cathepsin G deficiency to demonstrate or exclude the role of these proteases in a variety of pathologic conditions. We recently demonstrated that beige cathepsin G is tightly bound to neutrophil lysosomal membranes but is released in near normal quantities during exocytosis. Also, beige neutrophils contain a latent form of elastase that undergoes spontaneous activation when released under in vitro or in vivo conditions. However, the pathogenic potential of this enzyme in matrix degradation has not been ascertained previously. The possibility that in beige mice elastolytic proteases from neutrophils recruited into the lung have the capability to damage alveolar septa was investigated following an intratracheal instillation of N-formyl-L-methionyl-L-leucyl-L-phenylalanine (200 microg). Neutrophil influx was followed by a decrease in lung elastin content (-18%) and by a significant increase of the mean linear intercept (+30%) and of morphologic emphysema. The onset of pulmonary lesion was preceded by a marked increase of neutrophil elastase burden on the alveolar interstitium. The appearance of emphysema was prevented by administration of the serine protease inhibitor 4-(2-aminoetyl)-benzenesulfonyl fluoride hydrochloride (2. 4 microg/ml saline). These results demonstrate that the lung elastin degradation and emphysema can occur in beige lungs. The fact that the beige mouse does develop lung elastolytic changes after neutrophil recruitment indicates that this mutant cannot be considered a model of neutrophil function deficiency and used as a model of elastase deficiency.
Am J Respir Cell Mol Biol 1999 Feb
PMID:Neutrophil influx into the lungs of beige mice is followed by elastolytic damage and emphysema. 992 17

Human chymase (HC) is a chymotrypsin-like serine proteinase expressed by mast cells. The 2.2 A crystal structure of HC complexed to the peptidyl inhibitor, succinyl-Ala-Ala-Pro-Phe-chloromethylketone (CMK), was solved and refined to a crystallographic R-factor of 18.4 %. The HC structure exhibits the typical folding pattern of a chymotrypsin-like serine proteinase, and shows particularly similarity to rat chymase 2 (rat mast cell proteinase II) and human cathepsin G. The peptidyl-CMK inhibitor is covalently bound to the active-site residues Ser195 and His57; the peptidyl moiety juxtaposes the S1 entrance frame segment 214-217 by forming a short antiparallel beta-sheet. HC is a highly efficient angiotensin-converting enzyme. Modeling of the chymase-angiotensin I interaction guided by the geometry of the bound chloromethylketone inhibitor indicates that the extended substrate binding site contains features that may generate the dipeptidyl carboxypeptidase-like activity needed for efficient cleavage and activation of the hormone. The C-terminal carboxylate group of angiotensin I docked into the active-site cleft, with the last two residues extending beyond the active site, is perfectly localized to make a favorable hydrogen bond and salt bridge with the amide nitrogen of the Lys40-Phe41 peptide bond and with the epsilon-ammonium group of the Lys40 side-chain. This amide positioning is unique to the chymase-related proteinases, and only chymases from primates possess a Lys residue at position 40. Thus, the structure conveniently explains the preferred conversion of angiotensin I to angiotensin II by human chymase.
J Mol Biol 1999 Feb 12
PMID:The 2.2 A crystal structure of human chymase in complex with succinyl-Ala-Ala-Pro-Phe-chloromethylketone: structural explanation for its dipeptidyl carboxypeptidase specificity. 993 Dec 57

Evidence presented in the accompanying article (Gibbs, D. F., T. P. Shanley, R. L. Warner, H. S. Murphy, J. Varani, and K. J. Johnson. 1999. Role of matrix metalloproteinases in models of macrophage-dependent acute lung injury: evidence for alveolar macrophage as source of proteinases. Am. J. Respir. Cell Mol. Biol. 20:1145-1154) implicates alveolar macrophage matrix metalloproteinases (MMPs) in two models of acute lung inflammation in the rat. As a prerequisite to understanding which specific MMPs might be involved in the injury and how they might function, it was necessary to know the spectrum of enzymes present. To this end, alveolar macrophages were obtained from normal rat lungs by bronchoalveolar lavage, placed in culture with and without various agonists, and assessed by a variety of techniques for MMPs. The identification process involved characterization by gelatin, beta-casein, and kappa-elastin zymography, with confirmation of identity by Western blot/immunoprecipitation. Message levels of detected MMPs were assessed by Northern blot. Rat alveolar macrophages were found to produce a low constitutive level of MMP-2 (72-kD gelatinase A) that was only modestly upregulated following stimulation with phorbol myristate acetate, bacterial lipopolysaccharide, or immunoglobulin A-containing immune complexes. Although control cells were found to produce little or no MMP-9 (92-kD gelatinase B) or MMP-12 (metalloelastase), both enzymes were markedly upregulated upon stimulation. In the same stimulated macrophages there was little activity against type I collagen (associated with MMP-13 [collagenase-3] on the basis of Western blotting), no activity suggestive of stromelysin or matrilysin, and no measurable secretion of the serine proteinases, elastase and cathepsin G. These data demonstrate the ability of rat alveolar macrophages to elaborate certain MMPs under proinflammatory conditions, consistent with their possible involvement in the progression of acute inflammation.
Am J Respir Cell Mol Biol 1999 Jun
PMID:Characterization of matrix metalloproteinases produced by rat alveolar macrophages. 1034 Sep 32

Polycationic proteins, e.g., major basic protein from eosinophils or cathepsin G from neutrophils, have been shown to increase nonspecific airway responsiveness. Along with several indirect manners of action, polycations were reported to contract smooth-muscle strips and to raise the cellular Ca(2+) concentration as a direct action on airway smooth muscle. However, the mechanistic basis for the direct behavior remains to be elucidated. To address this issue, we examined the effects of synthetic cationic polypeptides poly-L-arginine and poly-L-lysine on fresh single smooth-muscle cells from bovine trachea using a patch-clamp technique. Both of the polycations significantly depolarized the membrane from a baseline of about -40 to -20 mV in a dose-dependent manner. The polycations also suppressed whole-cell spontaneous transient outward currents as well as both the conductance (from a baseline of about 130 to 70 pS) and open-state probability (about 25% of control values) of large-conductance Ca(2+)-dependent K(+) channel (maxi-K channel) on excised outside-out patch membranes. The polycations were without effect on the whole-cell Ca(2+) currents induced by depolarizing voltage pulses. We concluded that the synthetic polycations had at least two sites of action; one is the delayed rectifier K(+) channel that is responsible for the membrane depolarization that increases Ca(2+) influx, and the other is the maxi-K channel the suppression of which inhibits muscle relaxation. These results may explain the direct contractile action and, therefore, one of the mechanisms underlying the airway hyperresponsiveness induced by various polycationic proteins.
Am J Respir Cell Mol Biol 2000 May
PMID:Suppression of maxi-K channel and membrane depolarization by synthetic polycations in single tracheal myocytes. 1078 19

A neutral proteinase (NPS) was purified from the culture broth of Saccharomonospora canescens sp. novus, strain 5, using DEAE cellulose and a POROS HQ/M 4.6 x 100 mm column. The stability towards thermal and chemical (guanidine hydrochloride, Gdn.HCl) denaturation of NPS was investigated by kinetic and equilibrium studies. The unfolding processes were monitored by circular dichroism and fluorescence spectroscopy. The free energy of stabilization in water was calculated to be 2.1 kcal mol-1. The thermostability was determined by the critical temperature Tc from fluorescence measurements (69 degrees C) and the melting temperature Tm (70 degrees C) from (1) measurements. Quenching with acrylamide, iodide and cesium gives information about the microenvironment of intrinsic protein fluorophores. The Ksv constant for NPS is 4.6 and classifies the emitting tryptophans as 'buried' in the hydrophobic interior of the investigated protein.
Comp Biochem Physiol B Biochem Mol Biol 2000 Jan
PMID:Spectroscopic properties of a novel neutral proteinase from Saccharomonospora canescens. 1084 Jun 36

Bradykinin (BK) and kallidin (Lys-BK), liberated from kininogens by kallikreins, are ligands of the BK B(2) receptor. We investigated whether kallikreins, besides releasing peptide agonist, could also activate the receptor directly. We studied the effect of porcine and human recombinant tissue kallikrein and plasma kallikrein on [Ca(2+)](i) mobilization and [(3)H]arachidonic acid release from cultured cells stably transfected to express human BK B(2) receptor (CHO/B(2), MDCK/B(2), HEK/B(2)), and endothelial cells were used as control cells. As with BK, the actions of kallikrein were blocked by the B(2) antagonist, HOE 140. Kallikrein was inactive on cells lacking B(2) receptor. Kallikrein and BK desensitized the receptor homologously but there was no cross-desensitization. Furthermore, 50 nM human cathepsin G and 50 nM trypsin also activated the receptor; this also was blocked by HOE 140. Experiments excluded a putative kinin release by proteases. [(3)H]AA release by BK was reduced by 40% by added kininase I (carboxypeptidase M); however, receptor activation by tissue kallikrein, trypsin, or cathepsin G was not affected. Prokallikrein and inhibited kallikrein were inactive, suggesting cleavage of a peptide bond in the receptor. Kallikreins were active on mutated B(2) receptor missing the 19 N-terminal amino acids, suggesting a type of activation different from that of thrombin receptor. Paradoxically, tissue kallikreins decreased the [(3)H]BK binding to the receptor with a low K(D) (3 nM) and inhibited it 78%. Thus, kallikreins and some other proteases activate human BK B(2) receptor directly, independent of BK release. The BK B(2) receptor may belong to a new group of serine protease-activated receptors.
Mol Pharmacol 2000 Oct
PMID:Human bradykinin B(2) receptor is activated by kallikrein and other serine proteases. 1099 54


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