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)

The association of 17 beta-(3H)-estradiol with its pituitary cytosol receptor is described. The transformation products of this 8 S receptor complex at high salt concentration was analyzed by 5-20% linear sucrose gradients. KCl was found to reversibly convert the 8 S moiety into a 4-5 S species. The transformation by CaCl2 and trypsin was found to be irreversible. In addition, the nuclear translocation of the estrogen-receptor complex was investigated in vitro. Translocation was found to be temperature-dependent, since a 6 S nuclear receptor complex could be extracted from crude nuclei only after incubation of whole pituitaries at 37 degrees C and not at 4 degrees C incubation temperature. Similarly, a 6 S species was found upon sucrose gradient analysis of nuclear extract after a cell free incubation of isolated nuclei and cytosol with 17 beta-(3H)-estradiol. Maximal translocation was observed in this in vitro system within 60 to 90 min, resulting in a concomitant loss of cytosol receptor. The present data combine to suggest that nuclear translocation resembles one of the early events involved in the molecular action of estrogen at the pituitary level.
 ...
PMID:Transformation and translocation of 17 beta-estradiol receptor in rat pituitary. 31 66

1. The reactivities of phenylglyoxal (PGO), glyoxal (GO), and/or methylglyoxal (MGO) with several proteins, including ribonuclease A [EC 3.1.4.22] and its derivatives, alpha-chymotrypsin [EC 3.4.21.1], trypsin [EC 3.4.21.4], lysozyme [EC 3.2.1.17], pepsin [EC 3.4.23.1], rennin [EC 3.4.23.4], thermolysin, and insulin and its B chain, have been examined. From analyses of the reaction products, PGO was shown to be the most specific for arginine residues. GO and MGO also reacted rapidly with arginine residues, but they also reacted with lysine residues to a significant extent. A side reaction with N-terminal alpha-amino groups was observed with each of these reagents. 2. Two arginine residues out of four in ribonuclease A, two out of three in alpha-chymotrypsin, one out of two in trypsin, one out of two in pepsin, and one out of five in rennin appeared to react with PGO fairly rapidly, indicating a difference in the relative accessibility of these residues by the reagent. Extensive modification of the arginine residues by PGO occurred with RCM-derivatives of ribonuclease A and insulin B chain. The N-terminal isoleucine residues of alpha-chymotrypsin and trypsin appeared to be unreactive with PGO because of salt bridge formation with an aspartyl residue. The activity of alpha-chymotrypsin toward N-benzoyl-L-tyrosine ethyl ester and the lytic activity of lysozyme were lost rapidly on treatment with PGO, as in the case of ribonuclease A. Pepsin and rennin were only partially inactivated by reaction with PGO.
 ...
PMID:Further studies on the reactions of phenylglyoxal and related reagents with proteins. 32 41

A method for the rapid manual isolation of polytene chromosomes and nuclear membranes from salivary glands of Chironomus tentans is presented and the analysis of some of their RNA and protein components before and after treatment with 2 M salt solutions is summarized.--After salt-incubation the chromosomes still display a considerable number of bands which stain with ethidium bromide and which are sensitive to treatment with DNase, RNase, trypsin, and proteinase K, to a lesser extent with pronase and papain. Analysis of the iodinated residual proteins on SDS gels yield three major and two minor bands (MW between 50,000 and 70,000 dalton) which were also shown to be present in interphase chromosomes of Ehrlich ascites cells which had been treated similarly and are also tightly bound constituents of DNA prepared according to Gross-Bellard et al. (1973). This result indicates the existence of a general class of non-histone proteins involved in keeping the DNA in a supercoiled state. Furthermore their presence in salt-treated nuclear membranes of Chironomus salivary gland cells (and Xenopus oocytes, unpubl.) will be of interest with respect to functional aspects of the nuclear matrix.
 ...
PMID:Effect of salt-treatment on manually isolated polytene chromosomes from Chironomus tentans. 35 13

The authors studied immunochemical properties of the high molecular fraction of surface soluble antigens obtained by extraction with salt solutions from Sh. sonnei (virulent strain 1041) dried with acetone. The high molecular fraction was isolated by gel-filtration on Sepharose-4B. Along with the O-somatic antigen, this fraction contained thermostable and thermolabile antigens resistant to trypsin and RNA-ase treatment, and also protein-containing antigens disintegrated by trypsin. In difference from the O-somatic antigen, one of the thermostable components was completely precipitated with 50% alcohol.
 ...
PMID:[Immunochemical findings about the high molecular weight surface antigens of Shigella sonnei]. 36 91

Two effectors of ornithine decarboxylase (ODC; L-ornithine carboxy-lyase, EC 4.1.1.17) have been extracted from an ODC- (speC-) mutant, Escherichia coli MA 255. One of these is an ODC inhibitor (Mr 15,000 +/- 2000) that is labile to trypsin; its activity increases 20-fold in response to increased polyamine levels in the growth medium. It has additional characteristics similar to those of the ODC antizyme of eukaryote cells: it is a noncompetitive inhibitor of ODC; the complex formed between ODC and the ODC inhibitor can be dissociated with salt to provide active ODC and active ODC inhibitor; furthermore, this E. coli ODC inhibitor is inhibitory to eukaryote ODC. A thermostable nondialyzable factor that activates ODC in vitro has also been extracted from MA255; increased polyamine levels in the growth medium caused a 1.6-fold increase in the activity of this ODC activator. Effectors with comparable activities have also been identified in the parent ODC+ (speC+) strain MA197. The fluctuations of the intracellular levels of these two ODC effectors during the growth of E. coli MA255 have been related to the temporal changes of the activity of ODC in the parent ODC+ MA197 strain. The mode of interaction of these three macromolecules, as reflected in the changes of the activity of ODC, appears to be complex. The results suggest that ODC activity may be controlled post-translationally by macromolecules that act as positive and negative effectors and whose levels fluctuate in response to the concentration of the end products of the reaction.
 ...
PMID:Modulation of ornithine decarboxylase activity in Escherichia coli by positive and negative effectors. 36 95

Several kinds of hydrophilic proteins were examined to determine their interaction with artificial liposomes. Mitochondrial aspartate aminotransferase (m-GOT) [EC 2.6.1.1], as well as cytochrome c, was found to interact strongly with negatively charged liposomes. In each case, an appreciable amount of the protein bound to liposomes remained unreleased after raising the salt concentration in the medium. The m-GOT tightly bound to the liposomes was also found to become latent in its enzymatic activity, and could be reversibly activated by solubilization of the liposomes with detergent. This is also the case for cytochrome c, which ceases to be reducible by external reductant, such as dithionite. Furthermore, the tightly bound m-GOT was not susceptible to the proteolytic action of trypsin, or that of Nagarse. From these observations it can be inferred that these basic proteins interact with acidic liposomes not only electrostatically but also hydrophobically. This kind of hydrophobic interaction was not observed in the combination of positively charged liposomes and acidic proteins, including s-GOT. Mitochondrial GOT was shown to be bound to isolated intact mitochondrial, but the bound enzyme was fully active, in contrast to the case of acidic liposomes. The hydrophobic interaction of water-soluble protein with liposomes is discussed in connection with the penetration of matrix enzyme through mitochondrial membranes.
 ...
PMID:Interaction of mitochondrial aspartate aminotransferase with negatively charged lecithin liposomes. 37

Complexes between alpha-1-antitrypsin (alpha 1AT) and monoclonal IgA are regularly demonstrable in the plasma of myeloma patients. These alpha 1AT-IgA complexes, free of contamination by unbound alpha 1AT, are purified from 5 myeloma patients sera using salt-mediated hydrophobic chromatography. The complexes have a molecular weight greater than or equal to 400 000: this suggests that alpha 1AT is bound to di- or polymeric IgA. The alpha 1AT bound to IgA constitutes the 3.2, 3.5, 7.2, 8.5, and 24.6 per cent of the total alpha 1AT present in the 5 myeloma serum samples. There is a linear correlation between bound alpha 1AT concentration and IgA level in the range of the IgA concentrations considered (r = 0.988; p less than 0.05). Similar values are obtained quantitating bound alpha 1AT by radioimmunodiffusion technique or by determination of the trypsin-inhibiting capacity; this demonstrates that the bound alpha 1AT fully retains its inhibitory capacity. The biological significant of this binding phenomenon is discussed.
 ...
PMID:Inhibitory activity of alpha-1-antitrypsin bound to human IgA. 41 80

Insoluble elastin from copper-deficient animals has an amino acid composition intermediate between mature elastin and salt-soluble elastin (a higher lysine content and correspondingly low number of cross-links relative to the normal protein) and is solubilized by successive treatment with trypsin and chymotrypsin at 4 and 37 degrees C. Small amounts of B3H4 (11 mg--2 g of elastin) reduced allysine, allysine aldol, dehydronorleucine, and dehydromerodesmosine in insoluble elastin from copper-deficient pig aorta. In contrast, desmosine and isodesmosine were reduced only when a large excess of reductant (400 mg borohydride) was included in the reaction mixture. Reduction studies indicated that lysinonorleucine and merodesmosine were present in their dehydro forms to a greater extent in copper-deficient pig elastin than in normal elastin. After reduction with borohydride approximately 35% of the reduced form of the insoluble elastin remained insoluble after digestion with trypsin and chymotrypsin. A peptide containing the aldehyde oxidation product of lysine (allysine) and demonstrating an enrichment in glutamic acid was purified from the reduced form of copper-deficient pig elastin and partially sequenced. Its sequence (Gly-Ala-Glu-allysine-(Glu)...) and amino acid composition suggest: (1) clustering of glutamic acid residues in the elastin molecule, and (2) that allysine residues are not restricted to the alanine-enriched sites described for other elastin cross-links. Insoluble elastin from copper-deficient animals promises to be a useful tool for elastin sequence studies.
 ...
PMID:Characterization of insoluble elastin from copper-deficient pigs. Its usefulness in elastin sequence studies. 42 11

The size of androgen receptors from rat ventral and dorsal prostate, dorsal prostate (Dunning) tumor, testis, epididymis, and seminal vesicle was determined using Sephadex G-200 chromatogrpahy and sucrose gradient centrifugation. The protease inhibitor diisopropyl fluorophosphate (DFP) was used to minimize receptor breakdown. An 8-9 S, 85 to 106 A receptor (Mr = 280,000 to 365,000; f/fo = 1.9 to 2.4) observed in unfractionated cytosol prepared in low ionic strength buffer with or without DFP is in equilibrium with a 4.5-5 S, 58 A form (Mr = 117,000; f/fo = 1.8) observed at salt concentrations greater than 0.1 M KCl. Receptor partially purified using (NH4)2SO4 or phosphocellulose chromatography in the absence of DFP was present as smaller fragments of 3.6 S, 37 A and 3.0 S, 23 A. Similar fragments could be generated from the 4.5 S or 8 S receptor by mild trypsin treatment. In addition, ventral prostate contains a DFP-insensitive enzyme which specifically converts the 4.5 S, 58 A receptor to the 3.6 S 37 A fragment. The DFP-insensitive enzyme is partially inhibited by rabbit bile and appears similar to the enzyme seminin, a secretory protein of human prostate. Androgen receptor isolated in the presence of DFP from nuclei labeled in vivo is predominantly 4.5 S, 58 A, with smaller forms (37 and 23 A) appearing in the absence of DFP. The 4.5 S, 58 A nuclear receptors were also in equilibrium with a large 8 S form. Receptor breakdown by DFP-insensitive and sensitive proteases appears to be an in vitro phenomenon. Furthermore, the size of the androgen receptor is not significantly changed during receptor migration from cytoplasm to nucleus.
 ...
PMID:Effects of proteases and protease inhibitors on the 4.5 S and 8 S androgen receptor. 44 15

Fresh human skin extract made in salt solution after a prior buffer extraction was shown to enhance the hydrolysis of N-alpha-benzoyl-DL-arginine beta-naphthylamide (BANA) by trypsin. This trypsin enhancing effect was further shown to be both stabilizing and activating. After chromatography on Sephadex G-100, the trypsin binding factor was found in fractions of void volume. Protease binding took place in physiological and hypotonic but not in hypertonic NaCl-solutions (0.5 mol/l). The proteinase binding factor was further purified by trypsin-Sepharose 4 B affinity chromatography. It was found to bind also chymotrypsin and elastase and to be thermostable (100 degrees C for 20 min), precipitable at acidic pH (3.5), and by acetone and ammonium sulphate (60% saturation). The bound proteinases were found to preserve their hydrolytic activity towards protein substrates. Bound trypsin and chymotrypsin could completely be inhibited by soybean trypsin inhibitor. The binding factor did not react with anti-human-alfa2-macroglobulin antiserum from rabbit.
 ...
PMID:Proteinase binding and enhancing factor from human skin. 46 38


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