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Enzyme
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Target Concepts:
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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)
The availability of a patient with basophilic leukemia manifesting 75 to 90% mature basophils permitted the use of a cell concentration sufficient to generate and release mediators upon interaction with a calcium ionophore in quantities adequate for their physiocochemical characterization. The mediators were defined in terms of their physicochemical characteristics: slow reacting substance of anaphylaxis (SRS-A) by purification through silicic acid chromatography and inactivation by
arylsulfatase
; eosinophil chemotactic factor of anaphylaxis (ECF-A) by its gel filtration through Sephadex G-25 and inactivation by subtilisin and not
trypsin
; and platelet-activating factor (PAF) by its inherent binding to albumin. Both ECF-A and histamine were present in their preformed state, and for histamine it was possible to establish that the concentration per cell was comparable to that of normal human basophils. Dibutyryl cyclic AMP suppressed release of histamine and SRS-A, indicating that their availability was under a control similar to that observed with normal cells subjected to immunologic activation. The demonstration that a suspension of leukemic human basophils contained the preformed mediators, histamine and ECF-A, and generated SRS-A and PAF for release along with histamine and ECF-A, after activation with a calcium ionophore, establishes that a single cell type can serve as a source of the four recognized mediators of immediate-type hypersensitivity.
...
PMID:The release of four mediators of immediate hypersensitivity from human leukemic basophils. 4 47
Investigation of pure human pancreatic juice obtained by direct cannulation of the main pancreatic duct of 11 healthy volunteer subjects and 10 chronic alcoholics without detectable pancreatic disease revealed the presence of numerous acid hydrolases in this secretion. The pH optimal and substrate specificities of these enzymes suggest that they are of lysosomal origin. Stimulation of the pancreas by injection of cholecystokinin-pancreozymin (CCK-PZ) (1 Ivy dog unit/kg) resulted in a striking increase in activity of some of these hydrolases (N-acetyl-beta-D-glucosaminidase,
arylsulfatase
, etc.) similar to that observed for
trypsin
, amylase, and other pancreatic digestive enzymes. In a second group of hydrolases (beta-D-glucuronidase, leucine naphthylamidase, etc.) the effect of this hormone was greatly reduced or absent, particularly in normal individuals. In chronic alcoholics enzyme activity in response to CCK-PZ injection was greater than in normal subjects. Although this increase achieved statistical significance (P less than 0.05) in the case of beta-D-glucuronidase only, it was observed for all lysosomal hydrolases tested and suggests either increased synthesis or a more facile release of these enzymes from the pancreas of chronic alcoholics than of normal individuals.
...
PMID:Lysosomal enzymes in pure pancreatic juice from normal healthy volunteers and chronic alcoholics. 45 5
Chronic exposure of rats to 10% aerosols of papain or
trypsin
resulted in marked increases in lung weights and lung beta-glucuronidase and
arylsulfatase
activities. Destruction of alveolar walls was demonstrated microscopically as a decrease in the number of air spaces touching a line of known length. The pregnenes, progesterone and medroxyprogesterone acetate, but not the 19-nortestosterone derivative norethindrone, partially prevented the papain-induced breakdown of alveolar septa and elevation of beta-glucuronidase. The steroidal anti-inflammatory agent, paramethasone, completely inhibited the rise in lung weight and beta-glucuronidase activity, but did not prevent destruction of alveolar walls. The non-steroidal anti-inflammatory agent, indomethacin, afforded little or no protection. Limited prophylaxis against both histological and enzymatic changes was observed in rats treated with the anti-metabolite, cyclophosphamide, and the proteolytic enzyme inhibitor, aprotinin. The various lung abnormalities resulting from papain inhalation may thus be individually influenced by specific pharmacologic agents.
...
PMID:Lung enzymes in emphysematous rats: effects of progestagens, antiphlogistics and metabolic inhibitors. 116 8
The processing of preprocholecystokinin in human pituitary extracts was investigated using gel and ion-exchange chromatography monitored by sequence-specific radioimmunoassays before and after incubation with
trypsin
, carboxypeptidase B, and
arylsulfatase
. Whereas the neural lobe contained only the bioactive alpha-carboxyamidated cholecystokinin (CCK) peptides (32 pmol/g), of which CCK-8 predominated, the anterior lobe contained substantial amounts of three large nonamidated procholecystokinin fragments (95 pmol/g; Mrs, 9000, 7000, and 5000) and small amounts of alpha-amidated CCK (8.3 pmol/g). The latter occurred only in the following large molecular forms: component I, CCK-58, and traces of CCK-33. Corticotrophic tumors processed the large forms to small CCK-8-like forms as are found in the brain and in the gut. The results show that a hormone gene, although translated, is expressed only to a limited extent as mature, active peptide outside the principal production region(s). Thus the processing of CCK to small alpha-amidated peptides in the less-differentiated tumor tissue supports the hypothesis that differentiation of endocrine cells may be sustained also at the posttranslational level.
...
PMID:Preprocholecystokinin processing in the normal human anterior pituitary. 347 48
Using gel, ion-exchange, and reverse-phase chromatography monitored by radioimmunoassays specific for five sequences of preprocholecystokinin (prepro-CCK), its processing products were measured in neutral and acid extracts of porcine cerebral cortex before and after incubation with
trypsin
, carboxypeptidase B, and
arylsulfatase
. Three categories of peptides were found: biologically active peptides, i.e. peptides with the alpha-amidated COOH terminus Trp-Met-Asp-Phe-NH2, comprising large CCKs, i.e. peptides larger than CCK-58 and peptides eluting like CCK-58, CCK-33, and CCK-22; CCK-octapeptides in sulfated and traces of nonsulfated forms; and small CCKs, i.e. traces of CCK-7, large amounts of CCK-5, and modest concentrations of CCK-4 (the structures of CCK-5 and -4 were confirmed by sequence analysis); four NH2-terminal fragments, of which the two predominant ones correspond to the desnonapeptide fragments of CCK-58 and CCK-33; and COOH-terminal extended peptides corresponding to glycine-extended CCK-58, CCK-33, and CCK-8 in small but significant amounts. Thus, in addition to CCK-8 the porcine cerebral cortex synthesizes larger and smaller active CCK peptides in quantities of an order similar to those of CCK-8. The occurrence of these together with the NH2-terminal fragments and glycine-extended peptides can be explained only by the existence of different processing pathways for preproCCK. Consequently, the results suggest that cerebral CCK neurons are heterogeneous and comprise at least three populations with different biosynthetic machineries.
...
PMID:Characterization of preprocholecystokinin products in the porcine cerebral cortex. Evidence of different processing pathways. 370 Mar 74
Using gel and ion-exchange chromatography monitored by radioimmunoassays specific for sequences essential in the processing of preprogastrin and preprocholecystokinin, the products were characterized in extracts of porcine pituitary lobes before and after incubation with
trypsin
, carboxypeptidase B, and
arylsulfatase
. The intermediate and neural lobes contained only fully activated (i.e. alpha-amidated) preprogastrin products (component I, gastrin-34, and gastrin-17). In contrast, the anterior lobe contained, in addition to traces of alpha-amidated gastrin (2 pmol/g), hundredfold higher amounts of a nonamidated progastrin (189 pmol/g; Mr approximately 7000) and two nonamidated procholecystokinin fragments (75 pmol/g; Mr approximately 7000 and 5000). These results show that hormone genes, in spite of translation of their mRNA, are not necessarily expressed in functional peptides in cells outside the principal production regions. Hence, the study indicates that differentiation of endocrine cells may be controlled at the post-translational level.
...
PMID:Accumulation of nonamidated preprogastrin and preprocholecystokinin products in porcine pituitary corticotrophs. Evidence of post-translational control of cell differentiation. 370 Mar 75
Benzoyl- and isopentenoyl phosphoric triamides (BPA and IPA) strongly inhibited urease activities from jack bean, soybean, watermelon seed, Proteus mirabilis, P. rettgeri, P. vulgaris, Mycobacterium smegmatis, and Ureaplasma urealyticum. Their I50 values (the final concentration causing 50% inhibition), independent of enzyme source, were 2-21 nM, which are about 1,000-fold lower than that of caprylohydroxamic acid, one of the most potent urease inhibitors. ATP-urea amidolyase activity was inhibited 50% by BPA at a higher concentration of 0.28 mM, but was not affected by IPA even at 1.3 mM. Thirteen kinds of hydrolases (
trypsin
, chymotrypsin, thermolysin, leucine aminopeptidase, papain, lipase, alpha-amylase, glucuronidase, asparaginase,
arylsulfatase
, alkaline phosphatase, acid phosphatase, and true cholinesterase), two oxidoreductases (catalase and alcohol dehydrogenase), three transferases (glutamic-oxaloacetic aminotransferase, gamma-glutamyl transpeptidase, and arylsulfotransferase) and two kinases (pyruvate kinase and creatine kinase) were not affected at all even at 1 mM BPA and IPA. Exceptionally, pseudo-cholinesterase from human serum was inhibited by BPA and IPA, whose I50 values were 70 nM and 10 muM, respectively, using acetylthiocholine as a substrate. These values increased to 0.55 muM and 54 muM, respectively, when acetylcholine was used as a substrate. These results show that N-acylphosphoric triamides potently and specifically inhibit urease activity at concentrations of nM order.
...
PMID:Specific inhibition of urease by N-acylphosphoric triamides. 384 42
The degree of tyrosine sulfation and the distribution between gastrin-17- and gastrin-34-like immunoreactivity (LI) were studied in the antra of ten mammalian species. Specific radioimmunoassays, gel-, and ion-exchange chromatography as well as enzymatic cleavage with
trypsin
and
arylsulfatase
were used. The percentage of sulfation varied from 24.4 +/- 4.2 (mean +/- SEM) in dogs to 80.1 +/- 2.6 in sheep, 46.8 +/- 3.3 in humans, 50.1 +/- 3.2 in cows, 55.9 +/- 2.3 in rats, 57.4 +/- 3.1 in pigs, 61.3 +/- 2.2 in guinea pigs, 64.1 +/- 4.7 in cats, 64.8 +/- 2.1 in mice and 68.2 +/- 2.8 in rabbits. Gastrin-34-LI in antral extracts could be converted to gastrin-17-LI by
trypsin
in all species. Five percent of antral gastrins eluted as gastrin-34-LI in all species. We conclude that while the ratio of gastrin-34-LI to gastrin-17-LI varies little in mammals, large differences occur in the degree of sulfation.
...
PMID:Species variation in the tyrosine sulfation of mammalian gastrins. 398 36
The degree of tyrosine-O-sulfation and the ratio between large (gastrin-34 and component I) and small (gastrin-17 and -14) molecular forms of gastrin were studied in extracts of human fetal (n = 14) and adult (n = 9) antrum, duodenum, jejunum and pancreas. Boiled water extracts were applied to gel- and ion-exchange chromatography before and after treatment with
trypsin
and
arylsulfatase
. The fractions were monitored with sequence-specific radioimmunoassays that distinguish sulfated from non-sulfated gastrins. In antrum and duodenum about half the gastrins were sulfated at all stages of development. In the fetal jejunum gastrin occurred in sulfated form only while in the adult 72% (range, 64-88%) of the jejunal gastrins were sulfated. The larger molecular forms of gastrin predominated in the fetal compared with the adult antrum. In duodenum and jejunum, however, the ratio between small and large forms was the same in fetus and adult. Gastrin was undetectable in both fetal and adult pancreas. The results show that the degree of sulfation of gastrin varies substantially in the different parts of the gut at different stages of development. The differences may have functional significance, since sulfation increases the pancreozyminic and cholecystokinetic potency of gastrin.
...
PMID:Complete sulfation of jejunal gastrin in the human fetus. 400 48
The enzyme activities of four strains of Legionella pneumophilia were investigated by using the API ZYM system (API System S.A., F-38390 Montalieu Vercieu, France) and synthetic substrates. Aminopeptidases were detected specifically against L-alanine, L-arginine, L-aspartic acid, L-cystine, L-glutaminic acid, glycine, L-histidine, L-isoleucine, L-leucine, L-lysine, L-methionine, L-phenylalanine, L-tryptophan, L-tyrosine, and L-valine. Furthermore, the bacteria possesses esterase activity splitting propionate, butyrate, caproate, caprylate, and caprate, but not laurate, myristate, palmitate, and stearate, esters. The enzymes studies were inhibited partially by aprotinin. No inhibition of phosphatase (pH range, 5.4 to 8.5) or of phosphoamidase was observed. Activities of
arylsulfatase
, chymotrypsin,
trypsin
, and glycosidases could not be detected.
...
PMID:Enzymatic profile of Legionella pneumophilia. 616 35
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