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)

A method of isolation of alpha-1-antitrypsin (alpha-1-AT) in good yield from normal human plasma is described. A key step was affinity chromatography employing an antiserum which had been depleted of alpha-1-AT antibodies. The final preparations were homogeneous by immunological and physicochemical criteria. The specific activity of the purified alpha-1-AT was 0.363 mg of active bovine trypsin inhibited per 1.0 mg of inhibitor. Polyacrylamide gel patterns at both alkaline and acid pH of highly pure preparations frequently, but not invariably, showed multiple hands. Molecular weight studies by sedimentation equilibrium ultracentrifugation in aqueous buffer and in 6 M guanidine as well as sodium dodecyl sulfate polyacrylamide gel electrophoresis suggest that alpha-1-AT is a single polypeptide chain having a molecular weight of 49,500. Other physical and chemical properties of the inhibitor are described. A limited N-terminal sequence (Glu-Asp-Pro-Gln-Gly-Asx-Ala-Ala) was obtained. It was found that alpha-1-AT easily forms polymers and higher aggregates when exposed to denaturing agents such as 8 M urea and 6 M guanidine. The results suggest that aggregation is determined by both covalent and noncovalent forces.
 ...
PMID:Isolation, chemical, and physical properties of alpha-1-antitrypsin. 0 86

According to the previous findings of others, the trypsin inhibitory capacity of alpha-1-antitrypsin is irreversibly lost in acidic solutions below pH 5.0. In contrast, experiments reported herein show that considerable inhibitory activity can be regenerated as a time-dependent phenomena following titration to basic media. The rate of recovery of activity is accompanied by a decreasing amplitude in the fluorescent emission spectrum at 335 nm of acidified alpha-1-antitrypsin solutions following adjustment to pH 8.0. Acidic media also results in the slow, progressive formation of protein aggregates as measured using Sephadex gel filtration. This latter process is more prominent at pH 4.0, near the isoelectric point of alpha-1-antitrypsin than at pH 3 or 2. Both monomer and polymeric forms of alpha-1-antititrypsin were isolated before or after adjustment to basic media. Isolated monomeric material shows a high recovery of biological and immunological activity; aggregate forms, however, are immunologically cross-reactive but show little enzyme inhibitory activity.
 ...
PMID:Low pH stability of alpha-1-antititrypsin. 1

The purpose of this study was to explore a method by which an improved immunofluorescent staining can be applied to formalin-fixed paraffin sections to demonstrate cellular or tissue deposits of immunoglobulins, complement and fibrin, and to demonstrate alpha-1-antitrypsin storage and hepatitis B antigens in liver, toxoplasma in heart, and carcinoembryonic antigens in colonic cancer. It was shown that immunohistochemical demonstration for the above mentioned antigens, but not for complement, was feasible. The paraffin sections were first treated with trypsin and the indirect staining method was used. The trypsin treatment was found to decrease the nonspecific background fluorescence through digestion of the tissue. It probably also unmasked the immunoreactive sites of viral antigens and alpha-1-antitrypsin. In general, a 2-hour digestion was satisfactory for the types of tissues examined in this study, and an optimal period of digestion could be sought to obtain the best result for a specific antigen. This method may be a useful adjuvant to histopathologic study, in which a retrospective immunohistochemical examination may be desirable.
 ...
PMID:Application of immunofluorescent staining on paraffin sections improved by trypsin digestion. 6 99

Alpha-1-antitrypsin deficiency is responsible for emphysema in adults. The genetic polymorphism of this protein (Pi system) is used to detect these deficiencies. The relationship between the serum protease inhibitory capacities and M, MZ and Z Pi phenotypes was investigated. 120 sera including 31 M, 33 MZ and 56 Z were studied. The alpha-1-antitrypsin concentration varied according to the Pi phenotype, the sex and the health of the subject. The alpha-2-macroglobulin level did not depend on the Pi phenotype. The trypsin inhibitory capacity fluctuated with the age and the health of the subject, but did not faithfully represent the Pi phenotype. In contrast, the elastase inhibitory capacity depended only on the Pi phenotype. The relationship between alpha-1-antitrypsin levels and the serum elastase inhibitory capacities was linear. Canonical analysis was employed to determine the relative contributions of each antiprotease to the two inhibitory capacities. It appeared that the elastase inhibitory capacity was influenced more by the alpha-1-antitrypsin level while the trypsin inhibitory capacity was more sensitive to alpha-2-macroglobulin.
 ...
PMID:Tryptic and elastolytic inhibitory capacities of serum from various Pi phenotypes. 8 98

In 71 patients that underwent intracapsular extraction of the cataract it was possible to collect aqueous humor (a.h.) in sufficient quantities at the beginning and at the end of the operation. Using radial immunodiffusion albumin, IgG and alpha-1-antitrypsin were measured in the samples. In secondary a.h. huge variations in the concentrations were apparent. The primary permeability of the blood-aqueous barrier and the time between sampling had no influence on the relative increase of the proteins. No statistically significant difference was found between normotensives and hypertensives and patients with or without myopia of higher degree (over 6 diopters). The relative increase of proteins according to their difference in molecular weight followed the same pattern as described for anterior uveitis. In patients for whom an enzymatic zonulolysis with trypsin was used for the extraction, the relative increase of IgG was significantly smaller than in those that did not receive this treatment (P less than 0.005). The possible sources contributing to the formation of secondary a.h. are discussed.
 ...
PMID:Immediate changes in protein-concentration in aqueous humor induced by intracapsular lens extraction in human eyes. 11 24

The proteolytic activity of different proteinases during chronic otitis media can be inhibited by alpha-2-macroglobulin and alpha-1-antitrypsin. A new low molecular (13,000) acid stable and polyvalent proteinase inhibitor could be investigated in the middle ear secretion from patients with cholesteatoma and chronic otitis media. We believe that this inhibitor is identical with the low molecular inhibitor of bronchial mucus and the nasal fluid. This inhibitor shows a high anti proteolytic capacity and can inactive trypsin, chymotrypsin, pronase and leucocytic preoteinases. The inhibitor is not detectable in any case. We could find it in 55 cases, three specimens of middle ear secretions obtained no acid stable inhibitor. It is present in the secretion in a masked form by in situ-reaction with leucocytic proteinases. By denaturating deproteinizing it is liberated out of the complex with proteinases and can be measured. The investigations demonstrate that the level of the inhibitor varies during the course of a chronic otitis media. In the postoperative phase the inhibitor concentrations were clearly higher than preoperatively. A steep drop of inhibitor can be observed in cases of chronic otitis with the symptomatology of an acute inflammation. In cases with a chronic inflammation the inhibitor level seems to remain low. The decrease of the inhibitor is explained as a using up effect during reaction between inhibitor and leucocytic proteinases. We believe that this inhibitor in the middle ear secretion results from a limited proteolysis and splitting of inter-alpha-trypsin inhibitor by a proteolytic enzyme, possibly by kallikrein.
 ...
PMID:[The investigation of a low molecular acid stable proteinase inhibitor in the middle ear secretion (author's transl)]. 14 Sep 59

Three cationic proteins from the granules of human neutrophil granulocytes were obtained in a high degree of purity be means of affinity chromatography on 4-phenylbutylamine-Sepharose. Together with lysozyme, the three cationic proteins exhibit the highest electrophoretic mobility toward the cathode in acrylamide gels at moderately acid pH, among the granule constituents that are solubilized in 0.1 M phosphate buffer, pH 7.0, containing 1 M NaCl. The three cationic proteins represent a group of "neutral proteases" distinct from elastase and collagenase. They hydrolyze casein, azocasein and the chymotrypsin substrate N-acetyl-L-tyrosine ethyl ester. Optimal activity is found at pH 7.4-7;5. The enzymes are inhibited by the specific chymotrypsin inhibitor N-tosyl-L-phenylalanylchloromethane and by the naturally occurring inhibitors alpha-antichymotrypsin, alpha-1-antitrypsin, as well as by the trypsin inhibitors from soy beans and limabeans.
 ...
PMID:Cationic proteins from human neutrophil granulocytes. Evidence for their chymotrypsin-like properties. 23 18

Definite inherited defect in hereditary pancreatitis (HP) is not known. A new kindred with 3 definite and 6 suspected cases of HP was investigated for possible inherited abnormalities. No aminoaciduria (except for a slight rise in urinary histidine in one patient) and no hyperparathyroidism, hyperlipidemia, or chromosomal abnormality was present. An increase in serum IgM level of a polyclonal type was noted in 3 definitely affected sisters and also in 2 nonaffected members. Serum alpha-1-antitrypsin and serum trypsin inhibition were normal. However, very marked dilatation and ectasia of the pancreatic duct were found in the propositus. Reviewing the data from this family and previously described kindreds, it is postulated that the genetic abnormality in HP encompasses a wide variety of structural and anatomical defects in the sphincter of Oddi or the pancreatic ductal system. These predispose to intermittent obstruction of the duct with concomitant activation of enzymes and ductal metaplasia. In suspected cases an early effort should be made to outline the pancreatic duct as the defect may be amenable to surgery.
 ...
PMID:Inherited defect in hereditary pancreatitis. 30 62

alpha-1-Antitrypsin is a serum protein that inhibits many proteolytic enzymes. Recently, it was suggested that the alpha-1-antitrypsin-trypsin complex is an acyl ester analogous to the acyl intermediate that forms between trypsin and its substrates. In previous work we showed that the alpha-1-antitrypsin-trypsin complex can be split at high pH, releasing a component of alpha-1-antitrypsin. This component had a new carboxyl-terminal lysine, and it had lost a peptide of about 4000 daltons. In order to determine whether the alpha-1-antitrypsin is bound to trypsin through the new carboxy-terminal lysine, as would be expected if the above hypothesis is correct, we split the complex in the presence of 18OH-. When the new carboxy-terminal lysine was cleaved with carboxypeptidase B, singly labeled, doubly labeled, and unlabeled lysine were recovered. These data support the hypothesis that the alpha-1-antitrypsin-trypsin complex is an acyl ester or a tetrahedral precursor that is transformed into the acyl ester form at high pH. If other enzymes are bound by a similar mechanism, the methods used may be useful in determining which amino acids on alpha-1-antitrypsin bind covalently to each enzyme.
 ...
PMID:Specific lysine labeling by 18OH- during alkaline cleavage of the alpha-1-antitrypsin-trypsin complex. 30 70

When cultured in-vitro, originating from different breast cancer patients, tumor cells, identified histologically as carcinoma cells, varied in their proliferation patterns and cell morphology. If exposed for brief periods to vibrio cholera neuraminidaes (VCN), the amount of sialic acid released from the cells varied from one culture to another and increased with higher enzyme concentrations. If exposed to trypsin, the amount of released proteins varied also from one culture to another. Significant difference was observed between the effect of VCN or collagenase on normal and neoplastic cell cultures. Whether human or murine cell cultures, the cell-free media harvested from cultures of neoplastic cells containing high concentrations of collagenolytic-caseinolytic-fibrinolytic and esterolytic activities. Two effects of concanavalin A (Con A) have been distinguished on thymidine incorporation, the first is a decrease in the maximal thymidine uptake, whereas the second is a shift to the maximum thymidine uptake to higher Con A concentrations. At low concentrations, alpha-1-antitrypsin (AAT) had no effect, but at high concentrations it inhibited 3H-thymidine uptake. At low concentrations human profibrinolysin inhibited and at higher concentration sit enhanced uptake of the labeled precursor. Therefore, the collagen olytic caseinolytic-fibrinolytic enzyme is a pacemaker for proliferation of human mammary carcinoma cells.
 ...
PMID:Human mammary carcinoma cells. The enzyme pacemaker profibrinolysin. 31 26


1 2 3 4 5 6 7 8 Next >>