Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.21.1 (chymotrypsin)
10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Medullasin, a serine protease in bone marrow cells, resembles elastase, but is essentially devoid of elastinolytic activity. The protease revealed elastinolytic activity when small amounts of other proteases such as trypsin, papain, chymotrypsin, or collagenase coexisted in the incubation mixture. In vitro treatment of human monocytes with medullasin caused an increment of their cytostatic activity. Since medullasin failed to increase the cytostatic activity in the supernatant of monocytes, the enhancement of cytostatic activity of monocytes by medullasin is considered to be not mediated through the production of soluble factors from monocytes.
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PMID:Role of medullasin in granulocytes in biophylaxis. Elastinolytic activity and the potentiation of cytostatic activity of human monocytes. 306 Jan 33

The effect of pH and temperature on the apparent association equilibrium constant (Ka) for the binding of the recombinant proteinase inhibitor eglin c from leech Hirudo medicinalis to human leukocyte elastase (EC 3.4.21.37), bovine alpha-chymotrypsin (EC 3.4.21.1) and subtilisin Carlsberg (EC 3.4.21.14) has been investigated. On lowering the pH from 9.5 to 4.5, values of Ka for eglin c binding to the serine proteinases considered decrease thus reflecting the acid-pK shift of the invariant histidyl catalytic residue (His57 in human leukocyte elastase and bovine alpha-chymotrypsin, and His64 in subtilisin Carlsberg) from congruent to 6.9, in the free enzymes, to congruent to 5.1, in the enzyme:inhibitor adducts. At pH 8.0, values of the apparent thermodynamic parameters for eglin c binding are: human leukocyte elastase - Ka = 1.0 x 10(10) M-1, delta G phi = -13.4 kcal/mol, delta H phi = +1.8 kcal/mol, and delta S phi = +52 entropy units; bovine alpha-chymotrypsin -Ka = 5.0 x 10(9) M-1, delta G phi = -13.0 kcal/mol, delta H phi = +2.0 kcal/mol, and delta S phi = +51 entropy units; and subtilisin Carlsberg - Ka = 6.6 x 10(9) M-1, delta G phi = -13.1 kcal/mol, delta H phi = +2.0 kcal/mol, and delta S phi = +51 entropy units (values of Ka, delta G phi and delta S phi were obtained at 21 degrees C; values of delta H phi were temperature independent over the range explored, i.e. between 10 degrees C and 40 degrees C; 1 kcal = 4184J).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Binding of the recombinant proteinase inhibitor eglin c from leech Hirudo medicinalis to human leukocyte elastase, bovine alpha-chymotrypsin and subtilisin Carlsberg: thermodynamic study. 307 73

An acid-stable, low molecular mass proteinase inhibitor, bronchial mucus proteinase inhibitor (BMPI), has been isolated from sputum and partially characterised. A single band with a modal molecular mass of 18 700 was observed following SDS-polyacrylamide gel electrophoresis. BMPI inhibited human leukocyte elastase, cathepsin G, trypsin and chymotrypsin, but not porcine pancreatic elastase. Although BMPI had a molecular mass close to the similarly isolated inhibitor of Girard et al. (Girard, F., Tournier, J.M., Polu, J.M. & Sadoul, P. (1980), Bull. Eur. Physiopathol. Respir. 16 (Suppl.) 237-245), and although it showed immunological cross reactivity to the low molecular mass inhibitor of Kramps et al. (Kramps, J.A., Franken, C., Meyer, C.J.L.M. & Dijkman, J.H. (1981) J. Histochem. Cytochem. 29, 712-719), it was found to have an amino-acid profile different to any previously described inhibitor. BMPI was detectable in bronchoalveolar lavage fluid collected from healthy and diseased human lungs. The median molar ratio of BMPI/alpha 1-proteinase inhibitor (alpha 1 PI) observed in these lavage samples was 0.7, which is generally higher than those derived from the data of other authors. This suggests that BMPI is a different protein to those previously described, although its exact relationship to other low molecular mass proteinase inhibitors remains to be determined.
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PMID:Acid-stable low molecular mass proteinase inhibitors in human lung lavage. 308 87

Strong activity of acid-stable trypsin inhibitor (ASTI) was confirmed in some clinical thrombin preparations. Thrombin preparations of human plasma origin had no detectable ASTI activity, whereas some preparations of bovine plasma origin revealed more than 5,000 U/vial (5,000 thrombin units), indicating a higher content of ASTI than of thrombin in terms of protein concentration. Contamination by other biologically active substances was also suggested by variations in amidolytic activity with several synthetic substrates (S-2238, S-2251, S-2444, S-2266 and Bz-L-Arg-pNA). On isoelectric focussing, the ASTI activities migrated in acidic positions with pI values of 3.9, 4.5, 5.0, 5.9 and 6.5, respectively. They were almost parallel to the thrombin Bz-L-Arg-pNA hydrolytic activity, and differed from that of the purified thrombin preparation (pI = 7.0). By gel filtration on Sephadex G-100, the molecular weights of the inhibitors as calculated using standard proteins were 140,000 (main), 70,000 and less than 10,000 (minor), respectively. An immunological difference between the main inhibitor (pI = 3.9, mol wt 140,000) and previously reported plasma ASTI was also confirmed with goat anti-UTI serum by the double immunodiffusion and ELISA methods. The inhibitor exerted a strong inhibitory effect not only on trypsin and chymotrypsin, but also on non-plasmic fibrinolysis with human leukocyte elastase, and to a lesser extent on the blood coagulation system (lengthening of APTT and PT). Clearly, when using thrombin preparations and analyzing the data obtained after their administration, the effects of this and other contaminant biologically active substances must be taken into account.
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PMID:Strong activity of acid-stable trypsin inhibitor in bovine thrombin for clinical use. 314 Oct 90

Horse leukocyte elastase inhibitor rapidly forms stable, equimolar complexes with both human leukocyte elastase and cathepsin G, porcine pancreatic elastase, and bovine alpha-chymotrypsin. Formation of the inhibitor-pancreatic elastase complex results in peptide bond cleavage at the reactive site of the inhibitor so that a small peptide fragment representing the carboxyl-terminal sequence of the inhibitor is released. Sequence analysis of both this peptide, as well as that of an overlapping peptide obtained by enzymatic inactivation of native inhibitor with either Staphylococcus aureus metalloproteinase, Pseudomonas aeruginosa elastase, or cathepsin B, yields data which indicate that the reactive site encompasses a P1-P1' Ala-Met sequence. However, unlike the human endothelial plasminogen activator inhibitor, which also has a Met residue in the P1' position, oxidation of the horse inhibitor only slightly reduces its association rate constant with either of the elastolytic enzymes tested or with chymotrypsin. Comparison of the amino acid sequence at or near the reactive site of the horse inhibitor (P2-P18') with members of the serpin superfamily of proteinase inhibitors indicates that it not only belongs in this class but also represents the first example of a functionally active intracellular serpin.
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PMID:An elastase inhibitor from equine leukocyte cytosol belongs to the serpin superfamily. Further characterization and amino acid sequence of the reactive center. 336 85

An inhibitor of neutral proteinases was isolated from the cytosol of bovine leukocytes by anion exchange chromatography on Mono Q and gel filtration on a HPLC TSK column. The gel filtration resulted in two fractions with inhibitory activity which could be identified by sodium dodecyl sulphate-poly-acrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions as dimer and monomer of the inhibitor. The latter was shown to be homogeneous in SDS-PAGE with an apparent molecular mass of 40 kDa, with calibrated HPLC a molecular mass of 36.5 kDa has been determined. Isoelectric focusing followed by Western blot analysis revealed four bands in the pH range of 5.0 to 5.9. The inhibitor was found in bovine polymorphonuclear neutrophils (PMN), whereas lymphocytes and monocytes lacked this protein. No immunological cross-reactivity between the described cell-derived PMN-inhibitor (PMN-I) and alpha 1-proteinase inhibitor was detectable. The mechanism of inhibition for the serine proteinases chymotrypsin, trypsin, pancreatic elastase and leukocyte elastase was studied. PMN-I could not bind to PMS-chymotrypsin. The reaction of the serine proteinases with the PMN-I was characterized by the determination of the association rate constant kon.
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PMID:Neutral proteinase inhibitors in PMN leukocytes. I. Purification and characterization of a neutral proteinase inhibitor from bovine neutrophils. 342 3

(dl)-3-Benzyl-N-(methanesulfonyloxy) succinimide 5 has been found to inactivate human leukocyte elastase and alpha-chymotrypsin efficiently and irreversibly. The kobsd/[I] values were 1170 and 9000 M-1 s-1 respectively. Porcine pancreatic elastase was not inhibited by 5. Compound 5 may constitute the first example of a mechanism-based inhibitor of a serine proteinase that appears to exert its effect via an unprecedented enzyme-induced Lossen rearrangement.
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PMID:The Lossen rearrangement in biological systems. Inactivation of leukocyte elastase and alpha-chymotrypsin by (dl)-3-benzyl-N-(methanesulfonyloxy) succinimide. 364 25

A series of carboxy-alkylamidated and N-acetylated amino acids and peptides were synthesized and examined for their ability to inhibit human leukocyte elastase. The Boc-amino acid alkylamides were found to be potent specific and competitive inhibitors of this enzyme. They were found not to or only poorly inhibit several other serine proteinases such as bovine trypsin, alpha-chymotrypsin, porcine pancreatic elastase and human leukocyte cathepsin G at concentrations less than 10(-4) M. Specificity and maximum inhibition of human leukocyte elastase were achieved when the N-terminus of the amino acid was protected by a t-butyloxy-carbonyl (Boc) group, the oligopeptide fragment consisted of valine residues and when the alkyl chain was between 10 and 12 carbon atoms in length and attached to the C-terminus of the peptide fragment. Highest inhibition was obtained with the compound Boc-[Val]3-NH[CH2]11--CH3 (Ki = 0.21 microM). These specific inhibitors were also found to be non-toxic after oral administration to mice and rats (LD50 greater than 3.0 g/kg body weight).
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PMID:Synthetic inhibitors of human leukocyte elastase, Part 3. Peptides with alkyl groups at the N- or C-terminus. Non-toxic competitive inhibitors of human leukocyte elastase. 364 43

Human leukocyte elastase can be proteolytically inactivated by bovine pancreatic trypsin. Neither porcine pancreatic elastase nor bovine pancreatic chymotrypsin causes inactivation of leukocyte elastase, nor are trypsin, pancreatic elastase, or chymotrypsin themselves susceptible to proteolysis. The trypsin-catalyzed inactivation of leukocyte elastase can be slowed by inhibition of trypsin with benzamidine or by occupation of elastase's active site with elastatinal.
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PMID:Proteolytic inactivation of human leukocyte elastase. 384 35

Elasnin and 15 related 4-hydroxy-2-pyrones have been assayed for in vitro inhibition of human leukocyte elastase, porcine pancreatic elastase, and bovine chymotrypsin. Inhibition constants for HL elastase range from 0.1 to 10 mM. The principal determinant of potency against the elastases is probably the substituent at position 3, which may account for the observed strong homology between the elastases in their inhibition by these compounds. Acetylation of the 4-hydroxy group has no effect on inhibition. The inhibition is noncovalent; there is no evidence of enzyme acylation by these pyrones.
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PMID:Inhibition of human leukocyte elastase, porcine pancreatic elastase, and chymotrypsin by elasnin and other 4-hydroxy-2-pyrones. 406 6


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