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)

A trypsin inhibitor was isolated and purified from the bran of rice, Oryza sativa, by extraction with 1% sodium chloride, heat treatment, ammonium sulfate precipitation, ion-exchange chromatography on a CM-Sephadex C-25 and gel filtration on a Sephadex G-75. The final preparation was homogeneous by electrophoretic analysis. Rice bran trypsin inhibitor (RBTI) had a molecular weight of about 14,500 and an isoelectric point of 8.07. The amino acids, acid composition was characterized by high contents of basic amino acids, aspartic acid, glutamic acid, proline and cystine. BRTI inhibited bovine trypsin at an inhibitor-enzyme molar ratio of 1:1.6. It displayed, however, nobility to inhibit alpha-chymotrypsin, pepsin, papain and subtilisin BPN'.
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PMID:Purification and characterization of a trypsin inhibitor from rice bran. 50 53

1. We studied the effect of hyperosmolarity on human isolated airways because a better understanding of the effect of hyperosmolarity on the human airway wall may improve insight into the pathophysiology of hyperosmolarity-induced bronchoconstriction in asthma. 2. In cartilaginous bronchial rings dissected from fresh human lung tissue, hyperosmolar krebs-Henseleit buffer (450 mosM, extra sodium chloride added) evoked a biphasic response: a rapid relaxation phase (peak after 5.0 +/- 0.3 min) followed by a slow contraction phase (peak after 25.4 +/- 0.8 min). 3. With the histamine (H1) receptor antagonist mepyramine, the contraction phase was reduced to 41.2% of the control value (P less than 0.001), with atropine to 50.0% (P less than 0.01), with the local anaesthetic lignocaine to 48.7% (P less than 0.05) and with mepyramine together with atropine to 19.2% (P less than 0.001). 4. With the inhibitor of neutral metalloendopeptidase, phosphoramidon, the contraction phase increased to 128.0% of the control value (P less than 0.05) and after removal of the epithelium to 131.8% (P less than 0.05). 5. Indomethacin, the leukotriene C4/D4 (LTC4/D4) antagonist FPL 55712 or the blocker of nerve conduction, tetrodotoxin, had no effect on the contractile phase. 6. The relaxation phase was not altered by any of these drugs nor by epithelial denudation. The relaxation phase was also unchanged in the presence of alpha-chymotrypsin, which degrades muscle relaxing peptides such as vasoactive intestinal peptide. 7. Hyperosmolar buffer slightly increased the sensitivity and maximal response to methacholine as well as the cholinergic twitch to electric field stimulation. 8. We conclude that hyperosmolarity releases acetylcholine, histamine and neuropeptides in the human airway wall in sufficient quantities to contract airway smooth muscle. This release itself or its effect on airway muscle is modulated by the airway epithelium. The mechanism of the relaxation phase may be an unknown smooth muscle relaxing substance or a direct effect on the airway muscle, related to ion fluxes.
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PMID:Effects of hyperosmolarity on human isolated central airways. 185 21

Human neutrophil elastase from normal donors has been purified using an isolation procedure which included sequential sodium chloride extraction, Aprotinin-Sepharose affinity chromatography, CM-cellulose ion-exchange chromatography, and AcA44 gel filtration chromatography. The inclusion of this last purification step was crucial for separating inactive lower molecular weight species from the active forms of neutrophil elastase and resulted in a higher specific activity of the final preparation. Sodium dodecyl sulfate-polyacrylamide gradient gel electrophoresis of the reduced purified protein demonstrated three polypeptides of Mr 31,000, 28,000, and 27,500. Four polypeptides were resolved on acid gel electrophoresis; each of the four possessed amidolytic activity. Furthermore, peptide analysis of Staphylococcus aureus V8 protease digests indicated that these polypeptides are structurally related to each other and represent microheterogeneity of the purified protein. The apparent isoelectric points of these four forms as determined by two-dimensional electrophoresis range from 6.1 to 6.7. By utilizing microsequencing techniques, the first 40 residues of neutrophil elastase have been determined and compared with the reported sequence of elastase isolated from leukemic myeloid cells. In addition, a high degree of homology was found within the amino-terminal regions of neutrophil elastase and the serine proteinases porcine elastase, bovine chymotrypsin, human factor D, and the beta chain of plasmin.
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PMID:Isolation, characterization, and amino-terminal amino acid sequence analysis of human neutrophil elastase from normal donors. 385 49

The hydrophobic interactions of alpha- and beta-trypsin as a function of ionic strength and pH were studied by hydrophobic chromatography. Evidence was obtained that in spite of the identical specificities and similar activities of alpha- and beta-trypsin, the cleavage of the Lys-Ser bond induces conformational changes in the neighbourhood of the active site. Over a wide range of pH and salt concentration the non-polar residues on the surface of the molecule of beta-trypsin are more exposed to an external environment than on the molecule of alpha-trypsin. In the trypsin(chymotrypsin)-inhibitor complexes the majority of hydrophobic amino acids are buried; other hydrophobic residues localized on the surface contribute only very slightly to the interaction with the chromatographic support. The retention of trypsin, chymotrypsin and their diisopropylphosphoryl derivatives on a support with flexible hydrophobic ligands bonded to the matrix through a spacer (octyl-Sepharose) was correlated with the retention on a support with hydrophobic binding sites incorporated into the rigid matrix of the resin (Spheron). The native enzymes are always more retained; this indicates that the substitution results in the shielding of the non-polar residues in the neighbourhood of the active site. The differences in the slope of individual proteins, resulting from the correlation of the retention values obtained with both supports at several sodium chloride concentrations are explained by differences in the accessibility of the surface non-polar residues in the individual proteins. In experiments with model peptides the contribution of the individual hydrophobic amino acids to the retention was investigated.
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PMID:Model study of hydrophobic interactions of alpha- and beta-trypsin and alpha-chymotrypsin. 685 36

During or immediately after transcription of chromatin the high molecular weight pre-mRNA is complexes with proteins and low molecular weight RNA (lmwRNA). In the presence of a cytosolic RNase inhibitor pre-mRNA-protein complexes, designated as polyparticles, can be isolated from rat liver nuclei. The polyparticles are characterized by a maximum of their sedimentation coefficient of around 90 S, a protein to RNA ratio of 4.1, and a density in CsCl of 1.4 g/cm3. A set of 6--10 basic proteins of molecular weights between 30 and 45 kd as well as a multitude of polypeptides of higher molecular weights is associated with the rapidly labeled, polydisperse, high molecular weight RNA and several lmwRNA species. In order to study the structure of these very complex nuclear RNP complexes, the polyparticles were incubated at various concentrations of sodium chloride, urea or proteinases of different specificities (trypsin, chymotrypsin, proteinase K), recentrifuged through a sucrose layer and analyzed with respect to their sedimentation behavior, their protein to RNA ratios and their protein- and RNA components. Rhe results of these experiments led us to the proposal of a structural model which is presented here.
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PMID:The structure of ribonucleoprotein particles from rat liver nuclei. 701 68

Members of the serine proteinase inhibitor or serpin superfamily have a common molecular architecture based on a dominant five-membered A beta-pleated sheet and a mobile reactive center loop. The reactive center loop has been shown to adopt a range of conformations from the three turn alpha-helix of ovalbumin to the cleaved or latent inhibitor in which the reactive center loop is fully inserted into the A sheet of the molecule. While the cleaved state can be achieved in all inhibitory serpins only plasminogen activator inhibitor-1 and, more recently, antithrombin have been shown to adopt the latent conformation. We show here that the archetypal serpin, alpha 1-antitrypsin, can also be induced to adopt the latent conformation by heating at high temperatures in 0.7 M citrate for 12 h. The resulting species elutes at a lower sodium chloride concentration on an anion-exchange column and has a more cathodal electrophoretic mobility on non-denaturing polyacrylamide gel electrophoresis and isoelectric focusing than native M antitrypsin. Latent antitrypsin is inactive as an inhibitor of bovine alpha-chymotrypsin, is stable to unfolding with 8 M urea, and is more resistant to heat-induced loop-sheet polymerization than native but less resistant than cleaved antitrypsin. The reactive center loop of latent antitrypsin is inaccessible to proteolytic cleavage, and its occupancy of the A sheet prevents the molecule accepting an exogenous reactive center loop peptide. The activity of latent antitrypsin may be increased from < 1% to approximately 35% by refolding from 6 M guanidinium chloride.
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PMID:Preparation and characterization of latent alpha 1-antitrypsin. 789 Jun 40

The structure of the extension peptides retained on the tissue form of type V collagen molecules was determined. Type V collagen alpha chains containing extension peptides were extracted from fetal calf skin and bone by 4 M guanidine-HCl and 0.5 M acetic acid, respectively. Collagens present in both extracts were fractionated by sodium chloride precipitation. The collagen alpha(V) chains were then resolved by reverse-phase high performance liquid chromatography. The N-terminal extension peptides were characterized by direct sequence analysis after deblocking with pyroglutamate amino-peptidase and analysis of the products of digestion by bacterial collagenase, chymotrypsin, V8 protease and endoproteinase Lys-C. The results showed that the retained extension peptides on type V collagen molecules in the extracellular matrix of skin and bone were amino-propeptides and that the alpha 2(V) chain retains an intact amino-propeptide while the alpha 1(V) chain appears to be partially processed. The extended alpha 1(V) chain isolated from fetal calf bone gave an identical amino-terminal sequence to that of the alpha 1(V) chain isolated from fetal calf skin, suggesting that a specific enzyme may be involved in processing the alpha 1(V) amino-propeptide.
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PMID:Structural analysis of the extension peptides on matrix forms of type V collagen in fetal calf bone and skin. 826 15

Arylpiperazine derivatives were synthesized and investigated in this study. Two animal models, including an intraocular pressure (IOP) recovery method and an alpha-chymotrypsin-induced glaucoma model, were used to determine the ocular pharmacological effects of the arylpiperazine derivatives. In the IOP recovery method, New Zealand rabbits with normal IOP were instilled with 50 microliters of 0.5% eye drops, then 10% sodium chloride solution was infused through the ear marginal vein. The relative percent of IOPs were calculated, then delta IOPt% was obtained from the difference of IOPt% between the treated and controlled eye. In the alpha-chymotrypsin-induced glaucoma model, the induced glaucoma rabbits were topically instilled with 0.5% arylpiperazines onto the eyes, and then the IOP changes were calculated to evaluate the effect of eye drops. Our results showed that in the IOP recovery method, BG31 and YCT2-2 demonstrated a very significant effect for reducing IOP; delta IOPt% were -27.6 and -25.5 for BG31 and YCT2-2, respectively. Two other compounds, C219 and C220 also lowered IOP, but the effects were less significant. In alpha-chymotrypsin-induced glaucoma, the maximum effect of YCT2-2 on the IOP was found at 5 hrs. The delta IOP and delta delta IOP were -12.5 +/- 1.7 and -5.8 +/- 1.1 mmHg (p < 0.01), respectively. For BG-31 and C220, there existed a trend to increase IOP with time. In the study, we found that YCT2-2 with higher solubility in the acidic condition was correlated to the significant IOP lowering effect.
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PMID:Intraocular pressure lowering effects of novel arylpiperazine derivatives. 971 34

Proteoliposomes were prepared by making bilayer vesicles from neutral egg yolk lecithin and negatively charged alpha-chymotrypsin that had been previously stearoylated. Interaction of these proteoliposomes with a cationic polymer, poly-(N-ethyl-4-vinylpryidinium bromide) (PEVP) was examined. For comparison purposes, interaction of PEVP with egg lecithin vesicles containing an anionic phospholipid, cardiolipin, was also examined. Binding of PEVP to both types of vesicles was electrostatic in nature with the polymer manifesting a higher affinity to the cardiolipin relative to the enzyme. PEVP had no effect on the permeability of the bilayer membranes to sodium chloride. On the other hand, PEVP increased the transmembrane permeability of the nonionic anti-tumor drug, doxorubicin. The greater the negatively charged component in the membrane, the greater the PEVP effect. Polycation binding to the vesicles was accompanied by clustering of the stearoylated chymotrypsin (sCT) molecules within the membrane. This protein clustering is most likely responsible for the increase in the doxorubicin permeation. Enzymatic activity of the membrane-associated sCT remained unchanged upon PEVP binding. These findings seem relevant to the effects of polyelectrolytes on cellular membranes.
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PMID:Interaction of a cationic polymer with negatively charged proteoliposomes. 1151 11

The partitioning of bovine trypsin and alpha-chymotrypsin--proteases of similar physico-chemical properties--in different polyethyleneglycol/sodium citrate aqueous two-phase systems was investigated. The effect of different factors such as polyethyleneglycol molecular weight, pH, tie line length, temperature and the presence of an inorganic salt on the protein partition coefficient were analysed. Both a decrease in PEG molecular weight and an increase in pH led to a higher partition coefficient for both enzymes. Aqueous two-phase systems formed by PEG of molecular weight 3350 and citrate pH 5.2 showed the best separation capability which was enhanced in presence of sodium chloride 3%. The transfer of both proteins to the top phase was associated with negative enthalpic and entropic changes.
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PMID:Partitioning features of bovine trypsin and alpha-chymotrypsin in polyethyleneglycol-sodium citrate aqueous two-phase systems. 1730 4


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