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:3.4.16.2 (PCP)
3,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A novel mucoadhesive drug carrier system has been generated which protects a model polypeptide antigen from degradation by the most abundant intestinal proteases. The enzyme inhibitors antipain, chymostatin and elastatinal, respectively, were covalently attached to the mucoadhesive polymer sodium carboxymethylcellulose (NaCMC) and the inhibitory efficacy of the resulting polymer-inhibitor conjugates was evaluated in vitro. When these inhibitor conjugates were combined with the thiolated polymer polycarbophil-cysteine (PCP-Cys), 95.8 +/- 3.8% (mean +/- SD, n = 3) of the incorporated model antigen ovalbumin (OVA) was protected from enzymatic degradation within 90 min incubation in the presence of an artificial intestinal fluid containing the pancreatic serine proteases trypsin, chymotrypsin and elastase. Replacing the CMC-inhibitor conjugates in the dosage form by unmodified CMC significantly reduced the protective effect to 78.8 +/- 4.7% (mean +/- SD, n = 3), whereas incorporation of the model antigen in a CMC dosage form omitting PCP-Cys protected 72.5 +/- 3.2% (mean +/- SD, n = 3) of OVA from degradation within a 90 min incubation period. Further, the incorporation of PCP-Cys resulted in higher cohesiveness within the dosage form and controlled drug release of the antigen for a time period of more than 9 h. Results suggest that a delivery system combining thiolated polymer and polymer-inhibitor conjugates improves the metabolic stability of the model polypeptide antigen and may therefore be a useful tool for oral protein vaccination.
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PMID:Design and in vitro evaluation of a mucoadhesive oral delivery system for a model polypeptide antigen. 1159 93

In the present study, the features of two new thiolated polymers--the so-called thiomers--were investigated. Mediated by a carbodiimide cysteamine was covalently attached to sodium carboxymethylcellulose (Na-CMC) and neutralised polycarbophil (Na-PCP). Depending on the weight-ratio polymer to cysteamine during the coupling reaction, the resulting CMC-cysteamine conjugate and PCP-cysteamine conjugate showed in maximum 43 +/- 15 and 138 +/- 22 micromole thiol groups per g polymer (mean +/- S.D.; n=3), respectively, which were used for further characterisation. Tensile studies carried out with the CMC-cysteamine conjugate on freshly excised porcine intestinal mucosa displayed no significantly (P<0.01) improved mucoadhesion, whereas, the mucoadhesive properties of the PCP-cysteamine conjugate were increased 2.5-fold compared with the unmodified polymer. The swelling behaviour of the CMC-cysteamine conjugate was uninfluenced by the covalent attachment of the sulfhydryl compound. In contrast the swelling behaviour of the PCP-cysteamine conjugate was improved significantly (P<0.01) versus unmodified PCP. Furthermore, in aqueous solutions the disintegration time of tablets based on the CMC- and PCP-cysteamine conjugates was prolonged 1.5 and 3.2-fold, respectively, in comparison to tablets containing the corresponding unmodified polymers. According to these results, especially the PCP-cysteamine conjugate represents a promising new pharmaceutical excipient for various drug delivery systems.
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PMID:Polymer-cysteamine conjugates: new mucoadhesive excipients for drug delivery? 1183 40

Photocatalysts Pt/TiO2 coated on hollow glass beads were prepared by tetrabutyl titanate hydrolysis with Sodium silicate on hollow glass beads at various condition and loaded with platinum varying from 0.2% to 2.4% by weight. Sodium pentachlorophenolate (PCP-Na) solution were used to examined for their photoactivity and characterized by X-ray and BET. The results indicated that the optimization condition to prepare photocatalysts: Water to titanium alkoxides was 100, Sintering temperature was 650 degrees C, Diameter of hollow glass beads was 0.5 mm, TiO2: sodium silicate: hollow glass beads was 10:2.5:20, Platinum content of photocatalysts was about 1.4%-1.6%. When the experiments were carried out in such conditions, the initial concentration of PCP-Na was 100 mg/L, initial pH was 6.5, oxygen flux was 1.6 mL/s, illumination intensity was 30 kW.m-2, catalysts was 2 g/L, illumination time was 2 hours, respectively. Then the rates removals of PCP-Na could reach 92.0%.
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PMID:[Tetrabutyl titanate hydrolysis prepared TiO2 photocatalysis loaded with platinum technology]. 1198 10

Gavestinel [GV150526A; ( E)-3[(phenylcarbamoil)ethenyl]-4,6-dichloroindole-2-carboxylic acid sodium salt] is a selective antagonist at the strychnine-insensitive glycine site of the -methyl-D-aspartate (NMDA) receptor. It was tested for its ability to substitute for phencyclidine (PCP) in rats and rhesus monkeys trained to discriminate PCP from saline, under a two-lever fixed-ratio (FR) food reinforcement schedule, and for its ability to maintain responding in rhesus monkeys trained to self-administer PCP under a FR reinforcement schedule. No PCP-lever responding was observed after gavestinel (1-56 mg/kg i.p.) administration to rats discriminating PCP (2.0 mg/kg i.p.) from saline. The highest dose of gavestinel (100 mg/kg i.p.) tested eliminated responding. Likewise, no PCP-lever responding was observed after gavestinel (1-30 mg/kg s.c.) administration to rhesus monkeys discriminating PCP (0.08 or 0.1 mg/kg i.m.) from saline; the highest dose of gavestinel (30 mg/kg s.c.) tested reduced response rates to approximately 50% of those observed after its vehicle ( -cyclodextrin in 0.9% saline). Gavestinel (0.1-1 mg/kg per i.v. infusion) was not self-administered by rhesus monkeys that reliably self-administered PCP (0.0056 or 0.01 mg/kg per i.v. infusion). Infusion rates at the highest dose were typically lower than those for vehicle or saline, suggesting behavioral activity. Together, these results suggest that at behaviorally active doses gavestinel is not PCP-like and is likely to have low abuse liability.
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PMID:The selective glycine antagonist gavestinel lacks phencyclidine-like behavioral effects. 1240 96

A new membrane-associated 2,4,6-trichlorophenol reductive dehalogenase from Desulfitobacterium frappieri PCP-1 was isolated. Initial characterization of the crude preparation showed that the dechlorinating activity was sensitive to oxygen, and its optimum pH was 7.0. Its dechlorinating activity was not inhibited by sulphate, was completely inhibited by 1 mM sulphite, and partially inhibited by 5 mM sodium azide and by more than 5 mM nitrate. Several polychlorophenols were dechlorinated in the ortho position with respect to the hydroxy group. A dehalogenase was purified to apparent homogeneity. SDS gel electrophoresis revealed a single protein band with a molecular mass of 37 kDa. However, after two-dimensional gel electrophoresis, this band was composed of three isoforms. MS analyses showed that the three isoforms were from the same protein and the molecular mass of the most abundant isoform is 33800 Da. A mixture of iodopropane and titanium citrate caused a light-reversible inhibition of the dechlorinating activity, suggesting the involvement of a corrinoid cofactor. The apparent K(m) value for 2,4,6-trichlorophenol and pentachlorophenol were 18.3+/-2.8 microM and 26.8+/-2.9 microM respectively, at a methyl viologen concentration of 2 mM. The N-terminal amino acid sequence and an internal tryptic peptide sequence were determined. One open reading frame (ORF) was found in the Desulfitobacterium hafniense genome containing these peptides sequences. The corresponding ORF in D. frappieri PCP-1 was cloned and sequenced. This ORF, that we designated crdA, showed no homology with any known dehalogenase, suggesting a distinct reductive dehalogenase.
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PMID:Purification, cloning and sequencing of an enzyme mediating the reductive dechlorination of 2,4,6-trichlorophenol from Desulfitobacterium frappieri PCP-1. 1269 29

Semistatic acute toxicity tests of amphibian larvae (Xenopus laevis and Ambystoma mexicanum) were conducted at different developmental stages and by different methods to establish a simple amphibian-based assay. Test substance was pentachlorophenol sodium salt (PCP-Na). The endpoint was mortality and the 24-, 48-, 72-, and 96-h LC50 values were calculated by probit analysis. Interspecific differences in larval responses were not clear. Larval sensitivity tended to increase with larval age. Newly hatched larvae were most resistant to PCP-Na. During the tests of well-developed larvae, concentrations of dissolved oxygen and PCP-Na in the test solutions greatly dropped owing to uptake by the larvae. Therefore, middle-developed (2-week-old) larvae were most suitable for the test. Toxicity tests for volatile substances would be also possible using 2-week-old larvae in closed vessels. Test individuals should be kept individually to avoid the effects of poisonous skin secretions released from dead larvae.
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PMID:Examination of an amphibian-based assay using the larvae of Xenopus laevis and Ambystoma mexicanum. 1270 92

An outdoor model ecosystem was designed for the ecotoxicological evaluation of xenobiotics. Two years were necessary before the artificial pond reached a steady state. During this time the composition of the community and its functions were investigated. We recorded the amount of nutrients and the O(2)/CO(2)-metabolism in the water, the density and diversity of the phytoplankton, the aquatic macrophytes and the fauna, the microbial activity in the sediment, and the environmental impacts on the ecosystem. A short time before the application of sodium pentachlorophenate (Na-PCP) the ecosystem was divided into three identical subunits. One of these was used as an internal control, the others were contaminated with two different concentrations of Na-PCP (0.1 and 0.3 mg litre(-1)). These concentrations were maintained over a period of eight weeks. Ecological changes in the contaminated compartments were investigated during a period of one year. The results were compared with those of single-species tests. Significant variations were observed only in the unit receiving 0.3 mg Na-PCP litre(-1). A short time after starting the experiment, the number of rotifers and cyclopids decreased. Primary producers were not affected. An increase of the chloride levels in the water indicated degradation processes. One year after application of the chemical, the remineralisation of nutrients was disturbed. This resulted in a diminution of the phytoplankton and the aquatic fauna.
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PMID:Effects of sodium pentachlorophenate on the ecology of a freshwater model ecosystem. 1509 47

In this study an enzyme-linked immunosorbent assay (ELISA) was developed to detect the stress protein Hsp70 in the green alga Raphidocelis subcapitata. Using this ELISA, the response to a variety of pollutants, including ZnCl2, SeO2 (heavy metals), lindane (organochlorine pesticide), pentachlorophenol (PCP, chlorinated hydrocarbon insecticide and fungicide), carbaryl (carbamate pesticide) and sodium dodecyl sulphate (SDS; surfactant) was tested. Our results show that Hsp 70 is produced in a dose-dependent way in response to most chemicals investigated (except PCP) and at concentrations below the range of classical cytotoxicity testing (i.e. growth inhibition, lethality). Still, the potential to induce Hsp70 varied among the pollutants tested, the heavy metals ZnCl2 and SeO2 being the strongest inducers of Hsp70. Combined with the existing literature, these results indicate that Hsp70 in R. subcapitata is a sensitive biomarker for a wide range of environmental pollutants.
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PMID:Dose-dependent induction of heat shock protein 70 synthesis in Raphidocelis subcapitata following exposure to different classes of environmental pollutants. 1509 1

The biological toxicity of pentachlorophenol sodium (Na-PCP), a typical kind of aquatic organic pollutants, was tested with the MICROTOX system using luminescent bacteria with the influence of several factors taken into consideration. The EC50 of Na-PCP increases with the increasing of the pH and hardness of the sample. The EC50 (15 min) of Na-PCP is approximately equal to its EC50 (20 min). Compared with some common organic pollutants, which exhibit little influence on the toxicity of Na-PCP when mixed, Na-PCP is more toxic. A reduction of 14% in relative luminescent rate was observed in the experiment with a natural sample. The natural sample exhibits similar influence on the toxicity of Na-PCP similarly compared with unionized water.
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PMID:[Influential factors on the toxicity of pentachlorophenol sodium with MICROTOX system in water]. 1532 51

FXYD domain-containing proteins are tissue-specific regulators of the Na,K-ATPase that have been shown to have significant physiological implications. Information about the sites of interaction between some FXYD proteins and subunits of the Na,K-ATPase is beginning to emerge. We previously identified an FXYD protein in plasma membranes from shark rectal gland cells and demonstrated that this protein (FXYD10) modulates shark Na,K-ATPase activity. The present study was undertaken to identify the location of the C-terminal domain of FXYD10 on the alpha-subunit of Na,K-ATPase, using covalent cross-linking combined with proteolytic cleavage. Treatment of Na,K-ATPase-enriched membranes with the homobifunctional thiol cross-linker 1,4-bismaleimidyl-2,3-dihydroxybutane resulted in cross-linking of FXYD10 to the alpha-subunit. Cross-linking was not affected by preincubation with sodium or potassium but was significantly reduced after pre-incubation with the non-hydrolyzable ATP analog beta,gamma-methyleneadenosine 5'-triphosphate (AMP-PCP). A peptic assay was developed, in which pepsin treatment of Na,K-ATPase at low pH resulted in extensive cleavage of the alpha-subunit while FXYD10 was left intact. Proteolytic fragments of control and cross-linked preparations were isolated by immunoprecipitation and analyzed by gel electrophoresis. A proteolytic fragment containing FXYD10 cross-linked to a fragment from the alpha-subunit could be localized on SDS gels. Sequencing of this fragment showed the presence of FXYD10 as well as a fragment within the A domain of the alpha-subunit comprising 33 amino acids, including a single Cys residue, Cys254. Thus, regulation of Na,K-ATPase by FXYD10 occurs in part via cytoplasmic interaction of FXYD10 with the A domain of the shark alpha-subunit.
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PMID:Interaction of FXYD10 (PLMS) with Na,K-ATPase from shark rectal glands. Close proximity of Cys74 of FXYD10 to Cys254 in the a domain of the alpha-subunit revealed by intermolecular thiol cross-linking. 1591 65


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