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:3.4.21.1 (chymotrypsin)
10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Poly(A)-containing mRNA isolated from the islets of Langerhans obtained from two species of fish, angler fish (Lophius americanus) and sea raven (Hemitripterus americanus), stimulated protein synthesis 16-fold in a wheat germ cell-free system. Characterization of the translation products by polyacrylamide gel electrophoresis in sodium dodecyl sulfate showed a major polypeptide weighing 11,500 daltons that was specifically precipitated by an antibody against angler fish insulin. Partial sequence analysis of the amino terminal revealed that this polypeptide is preproinsulin, in which the amino terminus of proinsulin is preceded by either 23 (angler fish) or 25 (sea raven) amino acid residues. Translation of fish islet mRNA in a wheat germ cell-free system in the presence of dog pancreas microsomal membranes led to the correct cleavage of the nascent preproinsulin, resulting in the synthesis of authentic fish proinsulin, as verified by partial sequence analysis. Moreover, the synthesized fish proinsulin was segregated, presumably into the luminal space of the dog pancreas microsomal vesicles, because it was found to be resistant to proteolysis by added trypsin and chymotrypsin. Our data thus suggest that the mechanisms and information for the transfer of secretory proteins across the microsomal membrane are highly conserved during evolution.
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PMID:Cell-free synthesis of fish preproinsulin, and processing by heterologous mammalian microsomal membranes. 32 65

Poly-L-lysine with molecular masses of 3.3-290 kDa increased the amidolytic activities of leukocyte elastase and cathepsin G at low concentration, but had little effect on the activities of pancreatic elastase, alpha-chymotrypsin, plasmin and thrombin. Highly purified cathepsin G was obtained from column of EAH Sepharose 4B or Suc-L-Tyr-D-Leu-D-Val-pNA-Sepharose (affinity chromatography) by elution with poly-L-lysine solution (0.4 mg/ml, molecular weight (MW.) 290000 or 2.2 mg/ml, MW. 3300). Leukocyte elastase, adsorbed to Suc-L-Tyr-D-Leu-D-Val-pNA-Sepharose, was not eluted with poly-L-lysine solution. The amino acid composition of purified cathepsin G has been determined.
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PMID:Application of poly-L-lysine to purification of leukocyte cathepsin G by affinity chromatography. 139 85

Tumor promoters, such as phorbol esters or hormones, cause many biological effects which may contribute to the expression of cancer. The mechanism of cancer expression may have a common theme. One method of learning about this common mechanism is the identification of chemicals that interfere with tumor development. That there is actually a common theme between very different substances, such as inflammatory skin tumor promoters and estradiol causing breast cancer, was shown by the fact that both skin and breast cancers are suppressed by the same agents, e.g., protease inhibitors and retinoids. In addition to skin and breast, protease inhibitors suppress colon, bladder, and liver cancers. The substances that crossed over in suppressing many varieties of cancer were found to inhibit oxygen radical formation by tumor promoter-activated neutrophils and ras oncogene expression in NIH 3T3 cells. Poly(ADP)ribose polymerase (PADPR polymerase) may serve as the connecting link between oxygen radicals that cause its activation and oncogene expression. PADPR polymerase is inhibited by retinoids, antioxidants, and some protease inhibitors. Benzamide, an inhibitor of PADPR polymerase, is also a chymotrypsin inhibitor which suppresses oxygen radical formation by tumor promoter-activated neutrophils. The inhibition of PADPR polymerase causes the expulsion of some oncogenes from NIH 3T3 cells at definite times after oncogene transfection. Further work is required to find what are the contributions of PADPR polymerase to tumor promotion and of its inhibitors to suppression of oncogene expression.
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PMID:Suppression of tumor promotion by inhibitors of poly(ADP)ribose formation. 210 95

Thyroid hormones are known to modulate the concentrations of epidermal growth factor (EGF) in the mouse submandibular gland (SMG); this action is presumably mediated by the nuclear triiodothyronine receptor. To test the hypothesis that thyroid hormones act to increase SMG EGF concentrations by increasing the number of poly(A)+ -specific mRNA, poly(A)+ RNA was isolated from SMGs of neonatal mice which had been treated daily from birth through to 21 days of age with thyroxine (T4,0.4 microgram/g body weight). Poly(A)+ RNA also was extracted from SMGs of intact 21-day-old mice which had received vehicle alone. No significant differences in total nucleic acid, total RNA, or poly(A)+ RNA yields were noted between the two groups of animals. The isolated poly(A)+ RNAs from T4-treated and control mice were translated in an in vitro wheat germ system. Although no significant differences in efficiency of [35S]cysteine incorporation into trichloracetic acid precipitable material were noted between the two poly(A)+ RNA preparations, a significantly greater proportion of radioactivity was immunoprecipitable by anti-EGF antiserum in the translation medium derived from T4-treated mice (17.2 +/- 0.9%, mean +/- SEM) than in that of control mice (7.3 +/- 0.5%, P less than 0.001). Polyacrylamide gel electrophoresis of the immunoprecipitates (IMMP) revealed the presence of three radioactive bands with apparent relative masses (MrS) of 12,000, 9000, and 6000. The latter species comigrated with purified EGF, [125I]EGF, and an IMMP of a SMG extract. The translation product IMMPs following polyacrylamide gel electrophoresis were iodinated and digested with alpha-chymotrypsin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Thyroxine increases neonatal mouse submandibular gland mRNA-directed synthesis of epidermal growth factor. 242 79

Specimens of 14C-labeled poly(ethylene terephthalate), nylon 66, and poly(methyl methacrylate) have been synthesized and exposed, in vitro, to a number of enzyme solutions. Poly(ethylene terephthalate) was found to be affected by esterase and papain, although in different ways, but not by trypsin or chymotrypsin. Nylon 66 was unaffected by esterase but degraded by the other three. Poly(methyl methacrylate) was not affected by any of these enzymes. This indicates that some nominally stable polymers are susceptible to degradation by enzymes under some circumstances. The amount of degradation is small, but could have significant sequelae should it be reproduced in vivo.
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PMID:The enzymatic degradation of polymers in vitro. 295 61

This paper describes an investigation into the effect of alpha-1-antichymotrypsin (ACT) on DNA primase. DNA primase was partially purified from human stomach carcinoma cells. It was found that poly(dC)-dependent DNa primase activity was inhibited by ACT and the inhibition was proportional to the concentration of the inhibitor. The inhibitory effect of ACT remained even after ACT lost most of its chymotrypsin-inhibitory activity by heat treatment. Poly(dT)-dependent primase activity was enhanced by the presence of ACT. The enhancement was effective up to a concentration of 1mg/ml.
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PMID:Effect of alpha-1-antichymotrypsin on activity of DNA primase isolated from human stomach adenocarcinoma cells. 326 45

Poly-L-lysine has been demonstrated to partially replace biological cofactors in the activation of prothrombin by factor Xa. The present study was initiated to determine if poly-L-lysine has an effect on the enzymatic activity of factor Xa in the absence of prothrombin. At low ionic strength (50 mM Tris-Cl, pH 8.0, ambient temperature), poly-L-lysine inhibits amidase activity (S-2222) of bovine factor Xa with high affinity (Ki = 7 nM). The inhibition was readily reversed by 100 mM NaCl. The inhibition was also markedly reduced by the addition of 1.0 mM CaCl2 but not by MnCl2 or MgCl2. All three metal ions enhance amidase activity in the absence of poly-L-lysine. Poly-L-lysine also inhibits the amidase activity of factor Xa from which the gamma-carboxyglutamic acid domain has been removed by limited proteolysis with chymotrypsin (factor Xa-GD) but with somewhat lower avidity (Ki = 35 nM). As with native factor Xa, calcium ions reduce the observed inhibition while either manganese or magnesium ions are much less effective. The amidase activity of factor Xa-GD is enhanced with any one of the three divalent cations. These results provide additional support for the existence of a functionally significant binding site for calcium ions outside of the gamma-carboxyglutamic domain of factor Xa.
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PMID:Interaction of polylysine with bovine factor Xa: effect of divalent cations. 348 86

Poly(A)-containing RNA was isolated from total RNA of swine gastric mucosa by oligo(dT)-cellulose chromatography, and was translated in a wheat germ cell-free system. Analysis of the translation products by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that pepsinogen was a major translation product and was synthesized as two different molecular forms with apparent molecular weights of 45,000 and 43,000. The pepsinogen translated in the in vitro translation system had no autocatalytic activity. The pepsinogen mRNA was further purified by sucrose density gradient centrifugation, where the mRNA activity for pepsinogen was located around 15 S. At this stage, the translation product of the pooled fractions appeared to be almost exclusively pepsinogen. The peptide maps of the pepsinogen which was translated in vitro and digested by alpha-chymotrypsin and by Staphylococcus aureus V8 protease were nearly identical with the corresponding peptide maps of standard pepsinogen. The double-stranded complementary DNA which had been synthesized from the partially purified mRNA by avian myeloblastosis virus reverse transcriptase was cloned in Escherichia coli chi 1776, using plasmid pBR322 as a cloning vector. A colony carrying pepsinogen cDNA sequence was identified by in situ colony hybridization using the cDNA synthesized from the partially purified mRNA as a probe and further by a positive hybridization-translation assay. One of the recombinant clones (pSPcA1) had an insert of about 850 base pairs, and the nucleotide sequence analysis revealed that pSPcA1 codes for swine pepsinogen.
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PMID:Molecular cloning of complementary DNA to swine pepsinogen mRNA. 617 Jun 44

alpha,beta-Poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA), a synthetic water-soluble biocompatible polymer, was derivatized with glycidyl methacrylate (GMA), in order to introduce in its structure chemical residues having double bonds and ester groups. The obtained copolymer (PHG) contained 29 mol% of GMA residues. PHG aqueous solutions at various concentrations ranging from 30 to 70 mg/ml were exposed to a source of UV rays at lambda 254 nm in the presence or in the absence of N,N'-methylenebisacrylamide (BIS); the formation of compact gel phases was observed beginning from 50 mg/ml. The obtained networks were characterized by FT-IR spectrophotometry and swelling measurements which evidenced the high affinity of PHG hydrogels towards aqueous media at different pH values. In vitro chemical or enzymatic hydrolysis studies suggested that the prepared samples undergo a partial degradation both at pH 1 and pH 10 and after incubation with enzymes such as esterase, pepsin and alpha-chymotrypsin. Finally, the effect of irradiation time on the yield and the properties of these hydrogels was investigated and the sol fractions coming from irradiated samples, properly purified, were characterized by FT-IR and 1H-NMR analyses.
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PMID:New biodegradable hydrogels based on a photocrosslinkable modified polyaspartamide: synthesis and characterization. 1036 57

The potential of cyclodextrins to stabilize alpha-chymotrypsin upon encapsulation in Poly(lactic-co-glycolic) acid (PLGA) microspheres using a solid-in-oil-in-water (s/o/w) technique was investigated. Two cyclodextrins, hydroxyl-propyl-beta-cyclodextrin (HPbetaCD) and methyl-beta-cyclodextrin (MbetaCD), one insoluble and the other soluble in methylene chloride, were used. The results demonstrate that HPbetaCD failed to stabilize alpha-chymotrypsin upon encapsulation. Specifically, 19% of the protein was aggregated and the specific activity of the enzyme was reduced to ca. 50% of that prior to encapsulation. In contrast, MbetaCD significantly decreased the formation of aggregates to 3% and the retained specific activity of the enzyme was approximately 90%. The co-lyophilization of alpha-chymotrypsin with MbetaCD prior to encapsulation was a requisite to preserve the protein stability in microspheres. Furthermore, MbetaCD prevented the loss of protein during the preparation of microspheres and the encapsulation efficiency was improved to 90%. Release experiments showed the use of MbetaCD modified the release profile: the burst release decreased from 54% (in the absence of the excipient) to 36%. The results suggest that MbetaCD might be a suitable excipient to improve protein stability in s/o/w encapsulation procedures.
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PMID:Effect of cyclodextrins on alpha-chymotrypsin stability and loading in PLGA microspheres upon S/O/W encapsulation. 1649 95


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