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)

1. The reactivity of alpha-chymotrypsin toward p-nitrophenylacetate has been studied in dimethylformamide, dimethylsulfoxide, formamide and methylacetamide. p-Nitrophenol is liberated in dimethylsulfoxide only. 2. The reactions of alpha-chymotrypsin in dimethylsulfoxide are characterized by the same kinetic and equilibrium constants with either the p-nitrophenyl esters of straight chain carboxylic acids (from acetic to n-caprylic) or with the "specific substrate", N-carbobenzoxy-DL-phenylalanine p-nitrophenyl ester. This signifies that reactions of alpha-chymotrypsin in dimethylsulfoxide, unlike those in aqueous medium, have no specificity toward su-strate structure. 3. The stoichiometry of alpha-chymotrypsin reactions in dimethylsulfoxide was shown to be about five moles of substrate per mole of enzyme. After attaining this stoichiometry, the reaction is completed. 4. Optical rotatory dispersion spectra indicate that in non-aqueous media alpha-chymotrypsin undergoes a large conformational transition which results in a random coil. 5. Chymotrypsinogen, trypsin, trysinogen, lysozyme and serum albumin react with p-nitrophenylacetate in dimethylsulfoxide at rates which are approximately equal to those of alpha-chymotrypsin. Thus, the "activity" of alpha-chymotrypsin in dimethylsulfoxide toward p-nitrophenylacetate does not differ from the "activity" of other proteins, some of which are not even hydrolytic enzymes.
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PMID:The reactions of alpha-chymotrypsin and related proteins with ester substrates in non-aqueous solvents. 120 14

Synthesis of dipeptides benzoyl Arginine leucinamide and kyotorphin catalyzed by highly stabilized derivatives of trypsin and chymotrypsin have been performed. Extreme experimental conditions could be tested and parameters of industrial interest could be improved provided the high activity and stability of the derivatives in these unfavourable environments. Thermodynamically controlled synthesis catalyzed by trypsin could be optimized and 97% conversion was obtained in 90% organic cosolvents. 100% yields were achieved in kinetically controlled synthesis catalyzed by trypsin in aqueous medium in the presence of IM Ammonium Sulphate. Higher starting concentrations of poorly soluble substrates of chymotrypsin could be used in a reaction medium containing 50% DMF and 95% yield were obtained.
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PMID:Immobilization-stabilization of proteases as a tool to improve the industrial design of peptide synthesis. 182 29

Treatment of the transformed mouse embryo fibroblast cell line AKR-MCA with 1% N,N-dimethylformamide (DMF) resulted in the restoration of a nontransformed phenotype in these cells. In order to determine if an increase in growth inhibitory peptides might be responsible for these changes in growth properties of the DMF-treated AKR-MCA cells we examined the serum-free conditioned medium for its ability to inhibit the anchorage-independent growth of a human colon carcinoma cell line. The extracellular levels of inhibitory activity were two-fold higher in conditioned medium derived from AKR-MCA cells than in AKR-MCA cells grown in 1% DMF (AKR-MCA/DMF). Fractionation of the crude conditioned medium indicated the presence of an Mr 20,000 inhibitory fraction in AKR-MCA/DMF conditioned medium which was reduced in AKR-MCA cells. This Mr 20,000 inhibitory activity was acid and heat stable and sensitive to dithiothreitol and trypsin. In addition to inhibiting the growth of a human colon carcinoma cell line this protein induced colony formation in AKR-2B cells and competed for binding to the transforming growth factor beta (TGF-beta) receptor. Therefore, this Mr 20,000 inhibitory polypeptide induced by DMF is probably TGF-beta. TGF-beta was also shown to inhibit the growth of AKR-MCA cells in monolayer culture.
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PMID:Regulation of growth inhibitory activity in transformed mouse embryo fibroblasts. 288 48

The thermophilic enzyme 6-phosphogluconate dehydrogenase (6-phospho-D-gluconate:NADP oxidoreductase, decarboxylating, EC 1.1.1.44) from Bacillus stearothermophilus was much more resistant to inactivation under different conditions of temperature, pH, guanidine-hydrochloride, and organic solvents (dioxane, dimethylformamide, acetone) than its mesophilic counterpart from yeast. In addition, the thermophilic enzyme largely withstands proteolysis with trypsin, chymotrypsin, and elastase when compared with the yeast enzyme. It is proposed that thermophilic enzymes are not only thermostable, but also generally more stable to most common protein denaturants than their mesophilic counterparts. Because of their remarkable stability, enzymes isolated from thermophilic microorganisms may be ideally suited for technological applications.
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PMID:General stability of thermophilic enzymes: studies on 6-phosphogluconate dehydrogenase from Bacillus stearothermophilus and yeast. 638 90

Treatment of low-metastatic Lewis lung carcinoma cells (P-29) with dimethylsulfoxide (DMSO) in vitro enhanced their lung-colonizing ability. The effects of other highly polar compounds on the lung-colonizing ability of P-29 cells were examined. The following compounds were found to enhance the lung-colonizing ability of the cells: acetamide, N-methylacetamide, N-methylformamide, N,N-dimethylformamide, piperidone and hexamethylphosphoric triamide. Treatment of P-29 cells with DMSO or other polar compounds resulted in increases in activities of degradative enzymes, such as cathepsin B and plasminogen activator. The increases in cathepsin B and plasminogen activator activities were apparent after a 24 h treatment with DMSO and were suppressed by simultaneous treatment with cycloheximide, which suggested that they were due to syntheses of new proteins. DMSO-treated P-29 cells degraded [3H]leucine-labelled subendothelial matrix much more than did untreated cells. P-29 cells treated with DMSO or other polar compounds became attached to culture dishes more rapidly and were more resistant to detachment by trypsin treatment than untreated cells. A significant correlation was found between the degrees of adhesiveness of P-29 cells treated with various polar compounds and their lung-colonizing abilities.
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PMID:Enhancement of lung-colonizing ability of cloned low-metastatic Lewis lung carcinoma cells by treatment with highly polar compounds. 654 Feb 47

The total synthesis of human beta-lipotropin has been accomplished by the new segment-coupling method in aqueous solution. The peptides Ac-Arg-beta-lipotropin-(61-89) (I) and [GlyS60]-beta-lipotropin-(1-60) (II) were synthesized by the solid-phase method. Reaction of peptide I with citraconic anhydride followed by brief digestion with trypsin to remove the acetylarginyl group, gave Ia. Reaction of peptide II with citraconic anhydride gave the citraconyl peptide IIa. Ia and IIa were coupled together in 50% dimethylformamide by reaction with silver nitrate/N-hydroxysuccinimide. After removal of the citraconyl groups in 25% acetic acid, a 10% yield of synthetic beta-lipotropin could be isolated. The synthetic product was shown to be identical to native human beta-lipotropin by paper electrophoresis, isoelectric focusing, HPLC, lipolytic activity in isolated rabbit fat cells, and radioimmunoassay.
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PMID:Total synthesis of human beta-lipotropin. 657 18

The aim of this research is to show the alterations of alpha-actinin in rabbit myocardium after DMF treatment administered by forced inhalation. Z-lines observed with light and phase-contrast microscopy, appeared to be intact and they were clearly displayed by the indirect PAP-reaction. But if you consider that in normal muscle Z lines do not get coloured by the PAP-reaction without a previous light treatment with trypsin. It may be inferred that, in this case, The DMF has had the same effect as the trypsin, causing alteration to the protein structure. Besides the sarcomeric structure is undoubtedly altered by the DMF, causing alterations, in our opinion, similar to those found in rabbit skeletal muscle, under conditions of acute experimental ischemia.
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PMID:[Structural and ultrastructural changes in the rabbit myocardium exposed to dimethylformamide vapors]. 676 21

Low concentrations of methanol, 2-propanol and ethylene glycol increase the asymmetry of the flagellar waveforms ad the turning rate of both live sperm and potentially symmetrical sperm reactivated with 1 mM-MgATP2-, while at the same time causing a decrease in the heat frequency. Similar effects are observed if the solvents are added to preparations of potentially symmetrical sperm reactivated in the presence of 1 mM free Ca2+, or to potentially asymmetrical sperm reactivated without added Ca2+, A second group of solvents, N,N-dimethylformamide, formamide and p-dioxane, also decrease the flagellar beat frequency, but have the opposite effect on symmetry, reducing the asymmetry of the waveforms and the turning rate of potentially symmetrical sperm reactivated in the presence of 1 mM free Ca2+. These effects of solvents are all reversible within about 5 min after initial exposure to solvent. Higher concentrations of methanol and 2-propanol (above approximately 5 and 0.8 mole %, respectively) induce quiescence in potentially asymmetrical sperm reactivated with concentrations of MgATP2- ranging from 10 microM to 1 mM. The quiescent flagella initially assume a bent form very similar to that seen in Ca2+-induced quiescence, and show a subsequent time-dependent distortion of the initial bent from with eventual disintegration and splitting off of bundles of microtubules. Dimethylformamide, formamide and dioxane have almost no effect on the intrinsic asymmetry of potentially asymmetrical sperm reactivated in the absence of added Ca2+, but addition of these solvents to potentially asymmetrical sperm that have been induced to become quiescent by addition of 0.1 mM free Ca2+ causes the sperm to resume swimming with flagellar waveforms that are substantially more symmetrical that those of the starting preparation before the addition of Ca2+. Mild digestion with trypsin of reactivated sperm that have been induced either to beat asymmetrically or to become quiescent by addition of methanol causes a gradual appearance of symmetrical flagellar beating, as in the case of Ca2+-induced quiescence. The flagellar beat frequency, however, remains low, at about 20 Hz. The results suggest that the solvents either mimic or block the action of CA2+ by interaction with a Ca2+-dependent regulatory protein, and may also induce alteration in the rate constants of dynein ATPase.
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PMID:Effects of organic solvents on flagellar asymmetry and quiescence in sea urchin sperm. 707 22

An enzymatic method for converting tryptic peptides into their intermediates for the azide method of peptide synthesis was investigated by using model substrates, Bz-Arg, Bz-Gly-Arg, and Bz-Gly-Lys. The conditions favorite for the formation of the esters, hydrazides, and substituted hydrazides were deduced from the theoretical analysis on the pH and pKa dependence of the synthetic reactions and the pKa values of the substrates in various solvents. The theory based on the empirical relationship between the pKa of amines and the formation constant of the amides (Fersht, A.R. & Requena, Y. (1971) J. Am. Chem. Soc. 93, 3499-3504) indicates that the most favorite amine in the formation of amides is the one with a pKa value equal to the pKa of the carboxyl group and with such amines the amide formation takes place almost quantitatively even in aqueous solutions. Boc- and Cbz-hydrazine were found to satisfy the above condition approximately. The methyl esters of the substrates were formed in 30-35% yields in 50% aqueous methanol at pH near 4.5 by the reverse reaction of trypsin [EC 3.4.4.4]. Bz-Gly-Arg-NHNH2 was formed in a 34% yield in 2 M aqueous hydrazine and in 70-80% yields in 50% aqueous solutions of dioxane, DMF, and DMSO containing 1 M hydrazine at pH near 7. Bz-Gly-Arg-NHNH-Boc and Bz-Gly-Lys-NHNH-Boc were formed quite readily in 90-98% yields in H2O and in 50% aqueous solutions of dioxane, DMF, and DMSO containing 0.5 or 1 M Boc hydrazine at pH from 4 to 5. The Cbz-hydrazides of the peptides were also formed readily in 88-95% yields in the above mixed solvents containing 0.5 M Cbz-hydrazine. The formation constants of the hydrazides in H2O were in good agreement with those predicted by the empirical relationship. The formation constants in the form of log Ke in the mixed solvents calculated by taking the activity coefficients of the reactants as unity were 0.1 to 0.5 lower than the predicted values.
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PMID:Studies on protein semisynthesis. I. Formation of esters, hydrazides, and substituted hydrazides of peptides by the reverse reaction of trypsin. 724 Jan 24

A fragment of Micrococcus lysodeikticus cell wall was obtained by extraction of walls with water, dimethylformamide or dimethyl sulfoxide. The water-soluble polymer was obtained from the cell walls prepared either with or without trypsin treatment of the cell. This fragment was studied by the Smith periodate oxidation, methylation, mild acid treatment and enzymic procedures. The polymer consists of polysaccharide chains composed of (1-->4)-O-(2-acetamido-2-deoxy-beta-D-mannopyranosyluronic acid)-(1-->6)-O-alpha-D-glucopyranosyl residues. The polysaccharide chain is linked to C-6 of a 2-acetamido-3-O-(D-1-carboxyethyl)-2-deoxy-beta-D-gluco-pyranosyl residue of a peptidoglycan chain composed of repeating (1-->4)-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-(1-->4)-[2-acet ami do-3-O-(D-1-carboxyethyl)-2-deoxy-beta-D-glucopyranosyl] residues. The water-soluble cell-wall fragment was also observed in the-culture medium of Micrococcus lysodeikticus and was also extractable from the cells in minor quantity.
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PMID:A water-soluble fragment of Micrococcus lysodeikticus cell wall. 806 30


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