Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two alpha1-protease inhibitors were identified in rat serum. On polyacrylamide gels, one (R-I) appeared at the leading edge of the albumin, the other (R-2) at the trailing edge. The two inhibitors have differing molecular weights, differing inhibitory spectra toward proteases, and are immunologically distinct. The assays for antiprotease activity were performed on whole human and rat sera and inhibitor-enriched fractions of rat serum that had been electrophoresed on polyacrylamide gels. The more rapidly migrating antiprotease of rat serum, R-I, inhibited trypsin, chymotrypsin, and elastase. The more slowly migrating antiprotease, R-2, inhibited both trypsin and chymotrypsin but possessed only weak anti-elastase activity. When a comparison was made between human alpha1-antitrypsin and the more rapidly migrating rat inhibitor, it could be seen that they have similar molecular weights, similar inhibitory spectra, and similar electrophoretic mobilities. The relevance of the study of the R-I inhibitor in the pathogenesis of experimental emphysema is emphasized.
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PMID:Isolation and characterization of two alpha1-protease inhibitors in rat serum. 93 18

We purified the R1 alpha-1-protease inhibitor from rat serum and developed a convenient assay for its detection during purification procedures. Purification was accomplished by desalting, DEAE-Sephacel, zinc chelate, and reactive green-agarose columns. The resultant antiprotease had a molecular weight of 54,000 and inhibited elastase, chymotrypsin, and trypsin. By isoelectric focusing, five bands were produced with pI values from 4.3 to 4.7. Functional assays utilizing protease substrates imbedded in agarose plates were evaluated for the ability to distinguish the R1 alpha-1-protease inhibitor from the other serum antiproteases eluted in column chromatography fractions. This technique of screening for anti-protease activity was compared to conventional spectrophotometric methods and was found to correlate well when quantifying inhibition of elastase and chymotrypsin, but not trypsin. The presence of alpha-1-protease inhibitor was most reliably detected by testing for anti-elastase activity. Technician time and expense were saved by employing protease substrate plates to test chromatogrpahy fractions. This technique may facilitate purification of other protease inhibitors.
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PMID:Evaluation of assays for detecting alpha-1-protease inhibitor during purification from rat serum. 187 72

Various electrophoretic techniques, immunoblotting and inhibitions of trypsin and chymotrypsin were used to study the variability of serum proteins in farmed red deer, Cervus elaphus L., of Czechoslovakian origin. Easily interpretable polymorphisms were observed in transferrin (variants A, B1, B2, C) and vitamin D binding protein, GC (variants D, F, I, S). Great variability was observed in the protease inhibitors PI2, PI3, PI4, PI5, and PI8 and in unidentified zones in the vicinity of albumin, but no genetical or physiological interpretation for this variability is yet available. Haemopexin, alpha 1 glycoprotein, protease inhibitors PI1, PI6 and PI7 were monomorphic.
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PMID:Variation of some serum proteins in red deer, Cervus elaphus L. 226 75

We measured plasma alpha 1-proteinase inhibitor (alpha 1-PI) levels in patients with idiopathic nephrotic syndrome (INS), chance proteinuria and/or hematuria, and normal controls to examine the roles of proteinase inhibitors in the pathogenesis of renal diseases. Plasma alpha 1-PI concentrations were significantly decreased in patients with INS at relapses and remissions of INS. The alpha 1-PI activities, anti-trypsin and anti-elastase activities, were also decreased in relapses of INS. However, the values revealed no statistically significant difference in remissions of INS. Significant correlations between the PI activities and alpha 2-macroglobulin levels were revealed, which suggested a possible contribution of alpha 2-macroglobulin to the plasma PI activities in INS. From these results we conclude that the decrease in plasma alpha 1-PI activities may be responsible for the reduction of glomerular negative charge, possibly caused by some unknown proteinase(s), and the resultant development of proteinuria.
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PMID:[Decreased plasma alpha 1-proteinase inhibitor activity in idiopathic nephrotic syndrome]. 278 67

Serine protease inhibitors in extracts from three North American leeches, Nephelopsis obscura, Erpobdella punctata and Hemopis marmorata have been separated by anion exchange chromatography and the activity pattern against human granulocyte elastase and porcine chymotrypsin and trypsin determined. All three leech species contained a major peak with anti-trypsin activity, but Hemopis was unique in that the trypsin inhibitor was equally active against chymotrypsin. Nephelopsis was rich in anti-elastase activity of two types, one which was also active against chymotrypsin, and one which was a specific elastase inhibitor. Erpobdella contained inhibitors against elastase and chymotrypsin but with major activity against the latter.
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PMID:Serine protease inhibitors of North American leeches. 348 11

Tobacco plants were transformed with a cDNA clone of chymotrypsin/trypsin-specific potato proteinase inhibitor II (PI2) under the control of a constitutive promoter. Although considerable levels of transgene expression could be demonstrated, the growth of Spodoptera exigua larvae fed with detached leaves of PI2-expressing plants was not affected. Analysis of the composition of tryptic gut activity demonstrated that only 18% of the proteinase activity of insects reared on these transgenic plants was sensitive to inhibition by PI2, whereas 78% was sensitive in insects reared on control plants. Larvae had compensated for this loss of tryptic activity by a 2.5-fold induction of new activity that was insensitive to inhibition by PI2. PI2-insensitive proteolytic activity was also induced in response to endogenous proteinase inhibitors of tobacco; therefore, induction of such proteinase activity may represent the mechanism by which insects that feed on plants overcome plant proteinase inhibitor defense.
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PMID:Adaptation of Spodoptera exigua larvae to plant proteinase inhibitors by induction of gut proteinase activity insensitive to inhibition. 764 35

Three related alpha-protease inhibitors, PI2 I, PI3 C and PI4 C2, of blood serum of the pig (Sus scrofa) were isolated. PI2 I inhibited both trypsin and chymotrypsin; PI3 C and PI4 C2 strongly inhibited chymotrypsin, but did not significantly inhibit trypsin. By using SDS-PAGE, the three proteins were found to be composed of single polypeptide chains, and molecular weights were 63,000 for PI2 I, 58,000 for PI3 C and 64,000 for PI4 C2. All three proteins were shown to be glycoproteins. In PI3 C, eight sialic acid residues were found, and in PI4 C2 (similarly as in PI2 F) 10-11 residues were found. Amino acid composition as well as N-terminal sequences of the three proteins were very similar, indicating close homology. Comparison of these partial amino acid sequences with the cDNA-deduced amino acid sequence of pig alpha-antichymotrypsin (AACT; Buchman, 1989, GenBank, Accession No. M29508) revealed great similarities, the sequence of PI2 I being virtually identical with the pig AACT. On the basis of all available results, PI2 is proposed to be pig AACT, an orthologue of human AACT.
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PMID:Pig plasma alpha-protease inhibitors PI2, PI3 and PI4 are members of the antichymotrypsin family. 774 36

A further alpha-protease inhibitor system, PI4, was detected in porcine sera using either 2D agarose gel, pH 5.0-PAGE, pH 9.0, or 1D PAGE followed by immunoblotting with rabbit anti-porcine PI2 or PI3 antisera. PI4 inhibited chymotrypsin, but not trypsin. Seven allelic variants of PI4 were described. By haplotyping of alpha-protease inhibitor systems in 52 complete families it was shown that PI4 locus belongs to the PI gene cluster. The probable order of the PI loci was: PI1, PO1A, PI2, PI4, PI3.
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PMID:An additional locus (PI4) in the protease inhibitor (PI) gene cluster of pigs. 823 78

This study was designed to examine the inflammatory process in the central and peripheral airways of surgically resected lungs from asthmatic and nonasthmatic subjects. Lung specimens were inflated with cryoprotective, rapidly frozen, and systematically sampled. Cryosections prepared from frozen tissue blocks were fixed in acetone/methanol and immunostained with monoclonal antibodies by using the alkaline phosphatase-anti-alkaline phosphatase technique to detect CD3 (T cells), major basic protein (total eosinophils), EG2 (activated eosinophils), anti-tryptase (mast cells), anti-elastase (neutrophils), and CD68 (macrophages). All airways from patients with asthma demonstrated a significant increase in the numbers of T cells and total and activated eosinophils compared with airways from nonasthmatic subjects (p < 0.001). In the patients with asthma, the numbers of activated eosinophils but not T cells were significantly greater in airways with an internal perimeter less than 2 mm compared with those with an internal perimeter greater than 2 mm (p < 0.05). There were also significantly higher numbers of major basic protein-positive eosinophils, when expressed as a fraction of the alveolar wall tissue, in patients with asthma compared with control subjects (p < 0.05). In asthmatic airways with an internal perimeter of more than 2 mm, there was a greater number of activated eosinophils in the tissue between the epithelium and the smooth muscle compared with the tissue between the smooth muscle layer and lung parenchyma (p < 0.05). In contrast, there was a greater number of total eosinophils in the outer airway layer compared with the inner airway layer (p < 0.05). These results show that there is a similar but more severe inflammatory process present in the peripheral compared with the central airways of patients with asthma, which is consistent with the fact that the smaller airways are a major site of obstruction in asthma.
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PMID:Inflammation of small airways in asthma. 925 86

Bovine pancreatic trypsin inhibitor (BPTI) was secreted by Aspergillus niger at yields of up to 23 mg l-1 using a protein fusion strategy. BPTI was linked to part of the fungal glucoamylase protein (GAM) with a dibasic amino acid (KEX2) processing site at the fusion junction. Electrospray ionisation mass spectrometry and N-terminal protein sequencing revealed that, although biologically active in vitro, the purified products from a number of independent transformants consisted of a mixture of BPTI molecules differing at the N-terminus. Approximately 35-60% of this mixture was processed correctly. Aberrant processing of the GAM-BPTI fusion protein by the A. niger KEX2-like endoprotease was the most likely cause of this variation although the involvement of other fungal endoproteases could not be ruled out. In vitro studies have highlighted a weak interaction between BPTI and the Saccharomyces cerevisiae KEX2 endoprotease, suggesting that BPTI is not a potent inhibitor of KEX2p. A small proportion of the recombinant BPTI (10%) showed 'nicking' of the K15-A16 bond, indicating an interaction with a fungal trypsin-like enzyme. Mutant BPTI homologues designed to have anti-elastase activity, BPTI(K15V), BPTI(K15V,P13I) and BPTI(K15V,G12A), have also been expressed and secreted by A. niger. They also showed a similar spectrum of aberrant N-terminal processing but no 'nicking' of the K15-V16 bond was observed. Comparison of A. niger with other expression systems showed that it is an effective system for producing BPTI and its homologues, although not all molecules were correctly processed. This variation in processing efficiency may be useful in understanding the important determinants of protein processing in this fungus.
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PMID:Aberrant processing of wild-type and mutant bovine pancreatic trypsin inhibitor secreted by Aspergillus niger. 977 52


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