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)

Agarose gel electrophoresis (at pH 8.6) was used for qualitative determination of pancreatic enzymes in duodenal juice. The various enzymes were identified by staining techniques with specific chromogenic substrates, by quantitative determination of enzymes in eluates of gel slices, and by immunoelectrophoresis. The various protein bands corresponded to the following enzymes (from the anode to the cathode): chymotrypsin, trypsin, carboxypeptidase A, chymotrypsin, amylase (around the slit), lipase, elastase, and trypsin. The method was applied to a study of exocrine pancreatic function in 10 adults and 83 children suspected of having malabsorption. The duodenal juice, also analyzed for trypsin and amylase content, was collected in fasting condition and after a test meal of water. In patients with normal pancreatic function, all the enzyme bands were present and easy to recognize. In 87 patients carboxypeptidase A was present as two bands in 68 (80%), anodal trypsin as two bands in 39 (45%), and cathodal trypsin as two bands in 85 (97%). Electrophoresis of duodenal juice gave as much information from the fasting sample as after the test meal. Six children with pancreatic insufficiency (cystic fibrosis and Shwachmar's syndrome) had no or only faintly stained enzyme bands and a strongly stained albumin-containing band most anodally. The method is simple, rapid, and useful in routine work. The combination of this qualitative test with a quantitative one (e.g. trypsin determination) provides good information about exocrine pancreatic function.
 ...
PMID:Agarose gel electrophoresis of duodenal juice in normal condition and in children with malabsorption. 43 37

D-Alanine carboxypeptidase (CPase), a detergent-soluble penicillin-sensitive membrane enzyme of Bacillus stearothermophilus, Mr = 46,500, was digested with either trypsin or alpha-chymotrypsin to yield water-soluble fragments, designated T-CPase and Chy-CPase, respectively, each of Mr = approximately 45,000. These fragments were generated and purified in milligram quantities by digestion of CPase covalently immobilized on a penicillin affinity column. They retained full enzymatic activity, became significantly more resistant to thermal inactivation, and lost micellar detergent binding upon proteolysis. Each was derived from CPase by loss of a COOH-terminal hydrophobic peptide. CPase was reconstituted into bacterial lipid vesicles in an enzymatically active form. Penicillin-binding sites were equally distributed on both sides of the lipid bilayer, suggesting a random orientation of the CPase molecules. Neither T-CPase nor Chy-CPase reconstituted into lipid vesicles when treated in an identical manner. CPase was slowly cleaved from the surface of these vesicles by either trypsin or alpha-chymotrypsin, yielding T-CPase and Chy-CPase, respectively. These results demonstrate that CPase is comprised of a water-soluble catalytic domain and a COOH-terminal hydrophobic region which mediates the anchoring of this enzyme to the bacterial membrane.
 ...
PMID:Cleavage of a COOH-terminal hydrophobic region from D-alanine carboxypeptidase, a penicillin-sensitive bacterial membrane enzyme. Characterization of active, water-soluble fragments. 43 18

The effect of gamma irradiation (60Co) of different varieties and breeding lines of dry field beans (Phaseolus vulgaris) on chick growth was determined using a chick growth assay in which the diet contained approximately 50% beans. Total protein (N X 6.25) in beans was not changed appreciably by irradiation (21 Mrad) but protein solubility in water was decreased. Irradiation increased in vitro enzymatic digestibility of bean protein by pepsin and by a mixture of trypsin, chymotrypsin and peptidase. In the bioassay the diet was formulated to derive half of the total protein (22.6%) from beans. Autoclaved Pinto and Pink beans gave significantly better growth than Red Mexican and White Pea beans. The differences between Red Mexican and White Pea beans were not significant except for Red Mexican breeding line number RS-59. The nutritional value of all varieties of beans, based on chick growth, was significantly improved by gamma irradiation. The irradiation treatment of beans tended to increase nitrogen retention by chicks and decrease uric acid nitrogen excretion in relation to nitrogen intake.
 ...
PMID:Effect of gamma irradiation on nutritional value of dry field beans (Phaseolus vulgaris) for chicks. 44 72

The purpose of the study was to examine the secretory response of the exocrine pancreas in man to various doses of the synthesised decapeptide Caerulein (Takus), 5, 10 and 20 ng/kg Caerulein injected intravenously during an infusion of 0,5 CU/kg/h Secretin (GIH) produced a linear increase of enzyme secretion (amylase, lipase, trypsin and chymotrypsin) and also an increase in the water and bicarbonate secretion of the pancreas which is induced by Secretin. The injection of 40 ng/kg Caerulein led to no further increase of the ecbolic function. The intravenous injection of 1 Ivy dog unit (IDU/kg and 20 and 40 ng/kg Caerulein have an identical effect on the exocrine pancreas, there were no statistic differences.
 ...
PMID:[Effect of caerulein on the exocrine pancreas function in man; examinations of dose effects and comparisons with the effect of cholecystokinin/pankreozymin (author's transl)]. 49 1

A method is described for producing banding patterns with methyl green-pyronin (MGP) stain in chromosomes of fibrosarcoma cells. 1) The stain was made by mixing equal volumes of 2% aqueous pyronin G, 2% aqueous methyl green, distilled water, and 0.1 M acetate buffer (pH 5.7). 2) Treatment with colcemide and hypotonic KCl (0.075 M) was performed as usual. 3) Metaphase chromosomes were prepared using the flame-drying technique and treated with 0.25% trypsin at 37 C for 45 to 90 seconds. Before staining, the slides were rinsed in PBS, in distilled water, and then were dipped in 0.05 M acetate buffer. 4) Chromosomes were stained for more than 20 minutes, rinsed in distilled water, and hot-air dried. Satisfactory results were obtained in uncontracted metaphase chromosomes. MGP stain has the advantage of permitting much longer trypsin treatment and staining time than the trypsin-Giemsa method while providing satisfactory banding patterns.
 ...
PMID:Chromosomal banding patterns produced by methyl green-pyronin staining after trypsin treatment. 49 34

A method is described for obtaining and culturing large numbers of lung cells from normal adult male rats. The lungs were perfused in situ to remove blood cells and then perfused via the trachea with a trypsin-collagenase solution to initiate tissue digestion. The tissue was further digested in the enzyme solution and approximately 2 X 10(8) viable lung cells were obtained per animal. Primary cultures contained a mixed cell population. Through eight subcultures about 70% of the cell population possessed an epithelial-like morphology, whereas the remaining 30% was fibroblast-like. Three clones of epithelial-like cells were isolated at the fourth subculture. The mass culture lung cells and the epithelial-like clone that was studied retained a normal karyotype and did not grow in soft agar. Both the mass culture cells and the epithelial clone metabolized the lung carcinogen benzo(a)pyrene (BP) to water-soluble products. Furthermore, the mass culture lung cells metabolized BP to intermediate(s) which mutated Chinese hamster V79 cells from ouabain sensitivity to ouabain resistance. These lung cell cultures have potential use in cell transformation, mutation and carcinogen metabolism studies.
 ...
PMID:Culture of adult rat lung cells: benzo(a)pyrene metabolism and mutagenesis. 51 Dec 5

Washed human red blood cells from blood collected in EDTA were tested by Auto-Analyzer for a percentage of maximum antiglobulin haemagglutination (AH) using monospecific antisera to human C3d and C3c. The cells from normal persons were found to be agglutinated by anti-C3d but not by anti-C3c. To a fixed dilution of antiserum, the normal C3d AH values (X +/- 2 SD) were 34 +/- 19% for adult cells (n = 29) and 14 +/- 19% for cord cells (n = 19); the difference was significant (P less than 0.0001). By pretreatment of these cells with trypsin the C3d AH was either completely abolished or markedly reduced. Its difference between the adult and cord cells was eliminated as the observed values were 4 +/- 7% and 3 +/- 4% respectively (P = 0.15). The supernatant fluid of cell-trypsin mixture, treated with trypsin inhibitors, was found to be inhibitory to C3d AH but not to C3c AH. In contrast, the AH of C3d-coated red blood cells resulting from complement fixation in vivo (ie, cold agglutinin disease) or in vitro (eg, sucrose water reaction) was resistant to trypsin treatment. The difference between the trypsin-sensitive and trypsin-resistant cell-bound C3d is postulated to be at its attachment mechanism to the cell membranes. In addition, both the advantage and limitation of using trypsinised cells for C3d antiglobulin tests are demonstrated.
 ...
PMID:C3d antiglobulin haemagglutination of human red blood cells. A demonstration of two types of cell-bound C3d by means of typsin digestion. 52 93

The three-dimensional crystal structure of bovine trypsinogen at approximately pH 7.5 was initially solved at 2.6 A resolution using the multiple isomorphous replacement method. Preliminary refinement cycles of the atomic coordinates trypsinogen have been carried out first to a resolution of 2.1 A, and later to 1.9 A, using constrained difference Fourier refinement; During the process, structure factors Fc and phi c were calculated from the trypsinogen structure and final interpretation was based on an electron-density map computed with terms (2 Fo - Fc) and phases phic at a resolution of 1.9 A. Crystals of trypsinogen grown from ethanol-water mixtures are trigonal with space group P3121, and cell dimension a = 55.17 A and c = 109.25 A. The structure is compared with the bovine diisopropylphosphoryltrypsin structure at approximately pH 7.2, oirginally determined from orthohombic crystals by Stroud et al. (Stroud, R.M., Kay L.M., and Dickerson, R.E. (1971), Cold Spring Harbor Symp. Quant. Biol. 36, 125-140; Stroud, R.M., Kay, L.M., and Dickerson, R.E. (1974), J. Mol. Biol. 83, 185-208), and later refined at 1.5 A resolution by Chambers and Stroud (Chambers, J.L., and Stroud, R.M. (1976), Acta Crystallogr. (in press)). At lower pH, 4.0-5.5 diogen, with cell dimensions a = 55.05 A and c = 109.45 A. This finding was used in the solution of the six trypsinogen heavy-atom derivatives prior to isomorphous phase analysis, and as a further basis of comparison between trypsinogen and the low pH trypsin structure. There are small differences between the two diisopropylphosphoryltrypsin structures. Bovine trypsinogen has a large and accessible cavity at the site where the native enzyme binds specific side chains of a substrate. The conformation and stability of the binding site differ from that found in trypsin at approximately pH 7.5, and from that in the low pH form of diisopropylphosphoryltrypsin. The catalytic site containing Asp-102, His-57, and Ser-195 is similar to that found in trypsin and contains a similar hydrogen-bounded network. The carboxyl group of Asp-194, which is salt bridged to the amino terminal of Ile-16 in native trypsin or other serine proteases, is apparently hydrogen bonded to internal solvent molecules in a loosely organized part of the zymogen structure. The unusually charged N-terminal hexapeptide of trypsinogen, whose removal leads to activation of the zymogen, lies on the outside surface of the molecule. There are significant structural changes which accompany activation in neighboring regions, which include residues 142-152, 215-550, 188A-195. The NH group of Gly-193, normally involved in stabilization of reaction intermediates (Steitz, T.A., Henderson, R., and Blow, D.M. (1969), J. Mol. Biol. 46, 337-348; Henderson, R. (1970), J. Mol. Biol. 54, 341-354; robertus, J.D., Kraut, J., Alden, R.A., and Birkoft, J.J. (1972), Biochemistry 11, 4293-4303) in the enzyme, is moved 1.9 A away from its position in trypsin...
 ...
PMID:Structure of bovine trypsinogen at 1.9 A resolution. 55 51

Possible pitfalls in mapping studies utilizing the nuclear relaxation rates induced by paramagnetic probes are pointed out. In cases in which a distance is sought between a paramagnetic ion and a small molecule (e.g. substrate, inhibitor, etc.), both bound non-covalently to a macromolecule, heterogeneity in the system with respect to the binding of either of them may result in ambiguous conclusions. It is shown that the trypsin-gadolinium (III)-inhibitor system is heterogeneous, as revealed in the dependence of the water and inhibitor proton line-widths upon both the Gd3+ and the enzyme concentrations and in the effects of added Ca2+ on the line-widths. The results imply that in published work (Abbott et al. (1975) Biochemistry 14, 4935) the distance from a weak rather than from the strong metal ion binding site of trypsin (EC 3.4.21.4) may have been determined.
 ...
PMID:On the relative location of the inhibitor-and calcium-binding sites in bovine trypsin as determined by nuclear magnetic resonance. Possible ambiguities in paramagnetic probe mapping studies. 55 44

Microelectrode and tracer flux studies of the Urechis egg during fertilization have shown: (a) insemination causes a fertilization potential; the membrane potential rises from an initial level of -33 +/- 6 mV to a peak at +51 +/- 6 mV (n = 16), falls to a plateau of about +30 mV, then returns to the original resting potential 9 +/- 1 min (n - 10) later; (b) the fertilization potential results from an increase in Na+ permeability, which is amplified during the first 15 s by a Ca++ action potential; (c) the maximum amplitude of the fertilization potential, excluding the first 15 s, changes by 51 mV for a 10-fold change in external [Na+]; (d) in the 10 min period after insemination, both Na+ and Ca++ influxes increase relative to unfertilized egg values by factors of 17 +/- 7 (n = 6) and 34 +/- 14 (n = 4), respectively; the absolute magnitude of the Na+ influx is 16 +/- 6 times larger than that of Ca++; (e) in the absence of sperm these same electrical and ionic events are elicited by trypsin; thus, the ion channels responsible must preexist in the unfertilized egg membrane; (f) increased Na+ influx under conditions of experimentally induced polyspermy indicates that during normal monospermic fertilization, only a fraction of available Na+ channels are opened; we conclude that these channels are sperm-gated; (g) Ca++ influx at fertilization is primarily via the membrane potential-gated channel, because kinetics are appropriate, and influx depends on potential in solutions of varying [Na+], but is independent of number of sperm incorporations in normal sea water.
 ...
PMID:Ionic mechanism of the fertilization potential of the marine worm, Urechis caupo (Echiura). 57 95


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>