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:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Abnormalities of the interaction between alpha 2-macroglobulin and proteases have been suspected in cystic fibrosis. We measured the binding activity for trypsin of alpha 2-macroglobulin in 65 patients with cystic fibrosis, 41 obligate heterozygotes for cystic fibrosis, 18 children with asthma, 21 adult patients with chronic obstructive pulmonary disease, and 21 healthy control subjects. The assay was based on the observation that, once it is bound to alpha 2-macroglobulin, trypsin is no longer inhibited by soybean trypsin inhibitor. The bound trypsin retains activity against synthetic substrates such as N-alpha-benzoyl-arginine-p-nitroanilide. We found a moderately increased molar binding ratio of trypsin to alpha 2-macroglobulin in all patient groups and heterozygotes compared to healthy control subjects. The absolute concentration of alpha 1-macroglobulin was related to age rather than to the disease of the patient. Our data argue against a defect in protease-binding activity of alpha 2-macroglobulin in cystic fibrosis. The moderately increased binding activity observed could have been related to a structural difference in alpha 2-macroglobulin or to binding of ligands. This finding however, was not unique to patients with cystic fibrosis; the binding activity was increased in heterozygotes and in patients with other pulmonary diseases.
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PMID:Trypsin binding activity of alpha 2-macroglobulin in cystic fibrosis and other lung diseases. 615 57

alpha 2-Macroglobulin was purified from plasma of five cystic fibrosis patients and five normal controls. SDS gel electrophoresis of native alpha 2-macroglobulin from cystic fibrosis patients and normal donors showed identical subunit molecular weights, as did trypsin cleavage products. Cystic fibrosis and control alpha 2-macroglobulins were indistinguishable by isoelectric focusing and exhibited appropriate shifts in isoelectric point following binding of trypsin. The trypsin-binding capacities of control and cystic fibrosis alpha 2-macroglobulins did not differ, nor did the esterolytic activity of the trypsin-alpha 2-macroglobulin complexes.
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PMID:Cystic fibrosis alpha 2-macroglobulin protease interaction in vitro. 615 99

Alpha-2-macroglobulin (alpha 2-M) has been purified from the plasma of patients with cystic fibrosis and normal controls, and the proteolytic subunit cleavage on reaction with trypsin has been compared. As no differences were observed between the two groups, a primary genetic defect affecting alpha 2M subunit cleavage in cystic fibrosis is unlikely.
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PMID:Normal subunit cleavage of alpha-2-macroglobulin in cystic fibrosis. 615

To establish the diagnosis of acute pancreatitis the estimation of amylase in serum and urine, lipase and radio-immunoreactive trypsin in the serum are useful. Lipase estimations are more helpful than measuring amylase values. Trypsin-RIA-tests are increasingly important adults. But in chronic pancreatitis and inborn secretory insufficiencies of the pancreas these methods are less helpful. PABA-test, pancreolauryl-test (PLT), and the estimation of chymotrypsin in faeces are screening procedures, although their results correlate well amongst each other. As compared to the chymotrypsin estimation in faeces PABA test and PLT allow for some semiquantitative estimation of the secretory function and dynamics of the gland. The influence of malabsorption, liver and kidney diseases on these parameters is not yet quite clarified. Besides screening they are undoubtedly of value for judging the course and therapy of cystic fibrosis, Shwachman-syndrome, iatrogenic lesions by cytostatics (immunosuppressives and corticosteroids). Quantitative estimations of fat in faces and the pancreozymin test are no longer of significance.
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PMID:[Examination of pancreatic function in children with special reference to the PABA-test (author's transl)]. 616 2

Alterations in the pancreatic secretion of fluid and of enzymes in response to either pilocarpine (15 mg/kg) or an octapeptide of cholecystokinin (0.1 microgram/kg) have been found in rats that received daily injections of reserpine (0.5 mg/kg) for 7 days. During a 3-hr secretory period, significant reductions in the volume of pancreatic juice and in the total output of protein, amylase, and trypsin were observed in these animals. In the first hour of the secretory response, however, protease output was increased in the treated animals, particularly that of chymotrypsin, which was also increased in the longer secretory period following pilocarpine, but not cholecystokinin, stimulation. Zymogen granules isolated from the pancreas of the treated rats by differential centrifugation in a 0.3 M sucrose buffer had increased specific activities of the proteases when compared to those of untreated controls. Ultrastructurally, zymogen granules isolated from the pancreas of the treated rats showed changes in density, with bizonal and trizonal configurations being frequently observed, and had less distinct limiting membranes. In some, the membrane appeared broken at intervals, and there was granular material, presumably derived from the granule contents, lining the surface of the granule. It is concluded that pretreatment with reserpine inhibits fluid secretion and alters enzyme secretion in the rat exocrine pancreas. The latter effect is related to a nonparallel storage of amylase and proteases in the secretory granules induced by the drug treatment, probably through an action on protein synthesis or intracellular transport. An accumulation of proteases may lead to activation of these enzymes and to granule lysis. Inasmuch as the reserpine-treated rat has been proposed as an experimental model for cystic fibrosis, these findings are relevant in terms of possibly pathogenetic mechanisms in this disease.
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PMID:The chronically reserpinized rat as a model for cystic fibrosis: alterations in pancreatic enzyme secretion and storage. 617 40

The alpha 2-macroglobulin (alpha 2-M) was purified from the plasma of normal individuals and from that of cystic fibrosis patients. The proteins exhibited identical optical properties. Both proteins have an absorbance coefficient of A = 1060 g . cm-2 at 280 nm. The circular dichroism spectra are identical and indicate about 45% beta-sheet structure and almost no alpha-helix. The spectra of solutions at pH 8.0 do not change when trypsin is added. The fluorescence spectra of the alpha 2-M measured at pH 8.0 have contributions by tyrosine and tryptophan residues. The fluorescence intensities are identical and are enhanced about 30% when trypsin is added in 2:1 molar ratios.
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PMID:The optical properties of alpha 2-macroglobulin from normal and from cystic fibrosis plasma. 617 Apr 3

The interaction of alpha 2 macroglobulin (alpha 2M) with exogenous proteases has been reported by others to be abnormal in cystic fibrosis (CF). We have re-examined these claims. Four parameters were considered:(1) the molar protease binding of alpha 2M; (2) the interaction of bovine cationic trypsin (BCT), complexed to alpha 2M, with low molecular mass substrate, benzoyl arginine ethyl ester (BAEE); (3) the stability of formed alpha 2 M-BCT complexes; and (4) the subunit structure of alpha 2M. We have found CF alpha 2M to be similar to control alpha 2M in every respect studied.
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PMID:Protease binding by alpha 2 macroglobulin in cystic fibrosis. 617 20

Considerable attention has been focused recently on alpha 2-macroglobulin (alpha 2M), a major endopeptidase inhibitor in blood plasma, as a possible source of the primary defect in cystic fibrosis (CF). We report here studies designed to compare the structure of CF alpha 2M with normal alpha 2M to determine if there is a difference. The physicochemical properties of purified alpha 2M as revealed by various electrophoretic techniques, covalent proteinase binding properties, and primary structural studies on a variety of partial hydrolyzates of CF alpha 2M and normal alpha 2M are compared. These studies were carried out on eight different individual isolates of CF alpha 2M and three age-matched normal alpha 2M preparations and alpha 2M isolated from fetal cord blood. Three properties of CF alpha 2M were studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE): (1) the existence of four identically-sized subunits in the native molecule (10), (2) the cleavage of this subunit into fragments of approximately 100,000 daltons upon interaction with proteinases (10), and (3) the cleavage of an alkaline/heat sensitive bond to produce 120,000 and 60,000 dalton fragments (11). Both CF and normal alpha 2M were cleaved to the extent of 79-87%, CF alpha 2M behaves identically with normal alpha 2M with regard to all these properties. Salvesen and Barrett (24) have demonstrated that varying proportions of several [125I]-labeled proteinases form SDS-stable, non-reducible links to normal alpha 2M. Two of the CF alpha 2M preparations were studied to determine if similar covalent binding of proteinases occurred. The positions of the labeled and % of proteinase bound bands in SDS/reduced PAGE system were identical for normal alpha 2M and CF alpha 2M. These results indicate that CF alpha 2M behaves normally with regard to covalent binding of proteinases. Qualitative comparison of the peptide fragments separated by SDS-PAGE or isoelectric focusing of CF and normal alpha 2M produced by partial proteolysis with trypsin, chymotrypsin or Staphylococcus aureus V-8 proteinase did not reveal any difference unique to CF alpha 2M. The cyanogen bromide fragmentation studies and the cysteine cleavage studies also indicated that no major change in the positions of methionyl residues or cysteinyl/cystinyl residues has occurred in CF alpha 2M. The failure of all these different studies and those reported by others to demonstrate any differences between CF and normal alpha 2M makes it highly unlikely that there is a primary defect in alpha 2M in CF.
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PMID:Comparison of the structure and aspects of the proteinase-binding properties of cystic fibrotic alpha-macroglobulin with normal alpha 2-macroglobulin. 617 35

The isoelectric focusing (IEF) properties of human alpha 2-macroglobulin (alpha 2M) and alpha 2M-proteinase complexes from crude and partially purified preparations were studied by column IEF. The average isoelectric point (pI) of the major form was 6.5 for alpha 2M from crude plasma but was 5.3 for purified samples. Following preincubation with either trypsin, chymotrypsin or pancreatic elastase the crude alpha 2M-proteinase complexes displayed pI values ranging from 5.3 to 6.1 and the purified alpha 2M-proteinase complexes ranged from pH 6.0 to 6.1. A comparison of recoveries for focused crude or purified alpha 2M and trypsin-preincubated alpha 2M indicated enhanced recovery for the trypsin-preincubated samples suggesting that the binding of the proteinase enhances the stability of alpha 2M. alpha 2M thus displays column IEF properties which appear to be dependent upon the state of purity of the molecule. These findings are of particular significance to investigators concerned with using expressions of altered alpha 2M electrophoretic patterns for clinical diagnostic purposes in such diseases as multiple sclerosis, diabetes and cystic fibrosis.
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PMID:Differential isoelectric focusing properties of crude and purified human alpha 2-macroglobulin and alpha 2-macroglobulin-proteinase complexes. 619 30

alpha 2-Macroglobulin complexed to proteinases activated during clotting of cystic fibrosis and control sera was quantitated with the complex-specific monoclonal antibody F2B2 . Similar amounts of alpha 2-macroglobulin complexes (between 40 and 90 micrograms/ml) were generated in cystic fibrosis and control sera. Endocytosis of the complexes by normal human fibroblasts was compared to the amount of complexes detected by the F2B2 -radioimmunoassay. Normal uptake was observed with 13 out of 14 cystic fibrosis sera. One cystic fibrosis serum showed strongly reduced endocytosis of the complexes. Complexes isolated from this serum on immobilized F2B2 failed to inhibit binding of purified alpha 2-macroglobulin-trypsin to its receptor, demonstrating deficient receptor-binding of these complexes. The low uptake complexes could not be distinguished from complexes isolated from control or other cystic fibrosis sera by isoelectric focusing, rate electrophoresis or SDS-polyacrylamide gel electrophoresis.
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PMID:alpha 2-Macroglobulin-proteinase complexes in cystic fibrosis serum. Analysis by monoclonal antibodies and receptor-mediated endocytosis by normal human fibroblasts. 620 54


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