Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Research has shown that several PGs (prostaglandins) influence the following 3 major functions of the gastrointestinal tract: 1) gastric secretion; 2) motor activity; and 3) intestinal ion transport. The clinical and animal research literature on PG effects on motility and intestinal transport is summarized. PGEs and, to a lesser extent, PGF2a influence gastrointestinal motility. PGE, PGA, and PGF2a are involved in the process of water and electrolyte transport by the intestine. The article concentrates on what is known regarding PG effects on gastric secretion. The effect--inhibition of the gastric secretions--occurs in several species and in man. The inhibition includes all components of gastric juice--volume, acid, pepsin, and mucus. The effect is manifest in the basal state and in all secretogogues tested so far. The following mechanisms of action of this effect are discussed: 1) inhibition through changed gastric blood flow; 2) inhibition through a nervous mechanism; 3) operation through the cyclic AMP system; or 4) inhibition through interference with gastrin release or gastrin activity. Because certain PGs have these inhibitory effect on gastric secretions, it is possible that they can be used clinically in the treatment of peptic ulcers.
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PMID:Prostaglandins and gastric secretion. 1226 11

The atomic resolution structure of Leishmania mexicana triosephosphate isomerase complexed with 2-phosphoglycolate shows that this transition state analogue is bound in two conformations. Also for the side chain of the catalytic glutamate, Glu(167), two conformations are observed. In both conformations, a very short hydrogen bond exists between the carboxylate group of the ligand and the catalytic glutamate. The distance between O11 of PGA and Oepsilon2 of Glu(167) is 2.61 and 2.55 A for the major and minor conformations, respectively. In either conformation, Oepsilon1 of Glu(167) is hydrogen-bonded to a water network connecting the side chain with bulk solvent. This network also occurs in two mutually exclusive arrangements. Despite the structural disorder in the active site, the C termini of the beta strands that construct the active site display the least anisotropy compared with the rest of the protein. The loops following these beta strands display various degrees of anisotropy, with the tip of the dimer interface loop 3 having very low anisotropy and the C-terminal region of the active site loop 6 having the highest anisotropy. The pyrrolidine ring of Pro(168) at the N-terminal region of loop 6 is in a strained planar conformation to facilitate loop opening and product release.
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PMID:Crystal structure of triosephosphate isomerase complexed with 2-phosphoglycolate at 0.83-A resolution. 1252 13

Extensive spreading of liquid manure onto agricultural fields causes eutrophication of ground and surface water and also pollution of the atmosphere due to the high ammonium nitrogen content. A poly(gamma-glutamic acid) (PGA)-producing strain of Bacillus licheniformis was isolated in this study and investigated for its ability to reduce the ammonium nitrogen by converting ammonium into biomass and PGA as depot forms of nitrogen. In batch cultivations swine manure and an optimized mineral salts medium were used for PGA production. For example the cultivation of B. licheniformis strain S2 in liquid manure, which was modified by adding of 18 g citrate and 80 g glycerol l(-1) and exhibited a carbon to nitrogen ratio of 15.5:1, led to severe reduction of the ammonium content from 2.83 to 0.1 g x l(-1) and to the production of 0.16 g PGA and 7.5 g cell dry mass l(-1) within 410 h. Approximately 28% (w/w) of the total nitrogen was converted into cellular biomass, whereas 0.1% (w/w) was used for the production of PGA. In addition, approximately 33% (w/v) of the original ammonium was lost by stripping.
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PMID:Conversion of the nitrogen content in liquid manure into biomass and polyglutamic acid by a newly isolated strain of Bacillus licheniformis. 1258 95

Poly(glutamic acid) (PGA) is a water-soluble, biodegradable biopolymer that is produced by microbial fermentation. Recent research has shown that PGA can be used in drug delivery applications for the controlled release of paclitaxel (Taxol) in cancer treatment. A fundamental understanding of the key fermentation parameters is necessary to optimize the production and molecular weight characteristics of poly(glutamic acid) by Bacillus subtilis for paclitaxel and other applications of pharmaceuticals for controlled release. Because of its high molecular weight, PGA fermentation broths exhibit non-Newtonian rheology. In this article we present experimental results on the batch fermentation kinetics of PGA production, mass transfer of oxygen, specific oxygen uptake rate, broth rheology, and molecular weight characterization of the PGA biopolymer.
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PMID:Rheology, oxygen transfer, and molecular weight characteristics of poly(glutamic acid) fermentation by Bacillus subtilis. 1259 56

Bacillus sp. DT7 produced very high levels of alkaline and thermotolerant pectinase by solid state fermentation. Production of this enzyme was affected by nature of solid substrate, level of moisture content, presence or absence of carbon, nitrogen, mineral and vitamin supplements. Maximum enzyme production of 8050 U/g dry substrate was obtained in wheat bran supplemented with polygalacturonic acid (PGA; 1%, w/v) and neurobion (a multivitamin additive; 27 micro l/g dry substrate) with distilled water at 75% moisture level, after 36 h of incubation at 37 degrees C.
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PMID:Enhanced production of pectinase by Bacillus sp. DT7 using solid state fermentation. 1261 48

Highly water-soluble glycopolymers with poly(alpha-L-glutamic acid) (PGA) backbones carrying multivalent sialyl oligosaccharides units were chemoenzymatically synthesized as polymeric inhibitors of infection by human influenza viruses. p-Aminophenyl disaccharide glycosides were coupled with gamma-carboxyl groups of PGA side chains and enzymatically converted to Neu5Acalpha2-3Galbeta1-4GlcNAcbeta-, Neu5Acalpha2-6Galbeta1-4GlcNAcbeta-, Neu5Acalpha2-3Galbeta1-3GalNAcalpha-, and Neu5Acalpha2-3Galbeta1-3GalNAcbeta- units, respectively, by alpha2,3- or alpha2,6-sialytransferases. The glycopolymers synthesized were used for neutralization of human influenza A and B virus infection as assessed by measurement of the degree of cytopathic inhibitory effect in virus-infected MDCK cells. Among the glycopolymers tested, alpha2,6-sialo-PGA with a high molecular weight (260 kDa) most significantly inhibited infection by an influenza A virus, strain A/Memphis/1/71 (H3N2), which predominantly binds to alpha2-6 Neu5Ac residue. The alpha2,6-sialo-PGA also inhibited infection by an influenza B virus, B/Lee/40. The binding preference of viruses to terminal sialic acids was affected by core determinants of the sugar chain, Galbeta1-4GlcNAcbeta- or Galbeta1-3GalNAcalpha/beta- units. Inhibition of infection by viruses was remarkably enhanced by increasing the molecular weight and sialic acid content of glycopolymers.
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PMID:Chemoenzymatic synthesis and application of glycopolymers containing multivalent sialyloligosaccharides with a poly(L-glutamic acid) backbone for inhibition of infection by influenza viruses. 1262 82

Escherichia coli 3-deoxy-D-manno-octulosonate 8-phosphate (KDO8-P) synthase is able to utilize the five-carbon phosphorylated monosaccharide, 2-deoxyribose 5-phosphate (2dR5P), as an alternate substrate, but not D-ribose 5-phosphate (R5P) nor the four carbon analogue D-erythrose 4-phosphate (E4P). However, E. coli KDO8-P synthase in the presence of either R5P or E4P catalyzes the rapid consumption of approximately 1 mol of PEP per active site, after which consumption of PEP slows to a negligible but measurable rate. The mechanism of this abortive utilization of PEP was investigated using [2,3-(13)C(2)]-PEP and [3-F]-PEP, and the reaction products were determined by (13)C, (31)P, and (19)F NMR to be pyruvate, phosphate, and 2-phosphoglyceric acid (2-PGA). The formation of pyruvate and 2-PGA suggests that the reaction catalyzed by KDO8-P synthase may be initiated via a nucleophilic attack to PEP by a water molecule. In experiments in which the homologous enzyme, 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAH7-P) synthase was incubated with D,L-glyceraldehyde 3-phosphate (G3P) and [2,3-(13)C(2)]-PEP, pyruvate and phosphate were the predominant species formed, suggesting that the reaction catalyzed by DAH7-P synthase starts with a nucleophilic attack by water onto PEP as observed in E. coli KDO8-P synthase.
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PMID:Mechanistic insight into 3-deoxy-D-manno-octulosonate-8-phosphate synthase and 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase utilizing phosphorylated monosaccharide analogues. 1271 25

We report the results of a high throughput screening campaign that is aimed to develop a biodegradable polymer-based formulation to deliver active keratinocyte growth factor (KGF) and provide a means to tune the KGF delivery rate. A statistical design strategy was used to prepare and screen a series of polymer blends that were composed of poly(lactic acid) (PLA), poly(glycolic acid) (PGA), and the surfactant sodium bis(ethylhexyl)sulfosuccinate (Aerosol-OT, AOT). Chloroform was the solvent. Our high throughput screening method used a two-tiered assessment strategy. At Level 1, we identified "lead" KFG-loaded formulations that exhibited KGF emission spectra that were the most similar to the native KGF spectrum recorded in buffer. At Level 2, we used steady-state emission and a homogeneous polarization immunoassay strategy to determine the concentration of total and active KGF, respectively, liberated from the lead formulations during biodegradation. After preparing and screening 2500 formulations, we identified several viable, lead formulations. An analysis of the data showed that the combination of PLA, PGA, and AOT were important to yield a high fraction of active KGF upon release from the formulation; no combination of any two together produced an effect as good as the ternary formulation. The optimum formulations that yielded the highest fraction of active KGF upon release had the following general features: PLA/PGA (w/w) near unity, AOT loading of 100-200 mM, water/AOT mole ratio of 10-20, and a pH between 6 and 8. PLA alone cast from chloroform delivered KGF, but that KGF did not bind to anti-KGF antibodies (i.e., it was inactive). We can tune the KGF release kinetics by more than two orders of magnitude while maintaining the KGF activity upon liberation from the formulation by adjusting the PLA molecular weight.
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PMID:Tailored delivery of active keratinocyte growth factor from biodegradable polymer formulations. 1288 13

Selective extraction of specific cell components by enzyme or acid hydrolysis is possible from ultrathin sections for electron microscopy and parallel 2 micro sections for light microscopy of tissues fixed in formalin and embedded in a water-soluble polyepoxide, product X133/2097. Normal rat tissues fixed 15 minutes in formalin at 3 degrees C are more rapidly digested by proteinases than those fixed for the same length of time at 20 degrees C. Trypsin selectively attacks the nuclear chromatin and the ribonucleoprotein particles of the ergastroplasm, whereas mitochondria and zymogen granules resist tryptic digestion. Pepsin rapidly attacks the mitochondria and zymogen granules. The ergastoplasm and nucleus at first resist peptic digestion, but in time the entire cytoplasm and interchromatinic portion of the nucleus are attacked. Ribonuclease abolishes cytoplasmic basophilia in 2 micro sections, but parallel ultra-thin sections, stained with uranyl acetate and examined in the electron microscope, show no change in the ribonucleoprotein particles of the ergastoplasm. Desoxyribonuclease alone had no effect, but after pretreatment of the sections with pepsin or hydrochloric acid, desoxyribonuclease specifically attacked the nuclear chromatin. Nucleic acid-containing structures in the sections are gradually disintegrated by perchloric acid or hydrochloric acid.
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PMID:Ultrastructural cytochemistry. Enzyme and acid hydrolysis of nucleic acids and protein. 1376 Feb 8

Poly-gamma-D-glutamic acid from Bacillus licheniformis is a water-soluble, nontoxic, nonimmunogenic exopolymer. Using synthetic linkers, the alpha-carboxylate side chains of PGA were conjugated to an exposed thiol side chain of an antibody F(ab') fragment, Mc109F4. Analysis of the PGA-Mc109F4 conjugate by gel filtration HPLC revealed a mixture of multivalent conjugates. The PGA-Mc109F4 conjugate retained biological activity, but showed a lower binding affinity to target BCL3B3 cells than free Mc109F4 F(ab')(2) by flow cytometry, and a lower efficacy for BCL3B3 growth inhibition than free Mc109F4 F(ab')(2). PGA was also conjugated with the free amino group of glycopeptide antibiotic vancomycin. The PGA-vancomycin conjugate showed slightly lower antibacterial activity than free vancomycin versus susceptible Bacillus subtilis, but slightly higher activity versus intrinsically resistant Leuconostoc mesenteroides.
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PMID:Multivalent conjugates of poly-gamma-D-glutamic acid from Bacillus licheniformis with antibody F(ab') and glycopeptide ligands. 1462 28


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