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

A revised method to determine solubility of nitrogen in dilute pepsin, using 0.0002% pepsin in place of 0.2% in AOAC Official Method 971.09, was tested in 16 laboratories with 12 samples of fishmeal. Results were calculated according to 2 procedures: AOAC Official Method 971.09 and a method described in 1964 by researchers at the Torry Research Station (Aberdeen, Scotland), and generally referred to as the modified Torry method. Variations in the method of shaking and source of pepsin were also investigated. Pepsin solubility values were lower and more variable when calculated by the Torry procedure. The method of shaking apparently affected the result when calculated according to the Torry but not the AOAC method. The source of pepsin had no significant effect on between-laboratory variability, but a comparison of the 2 main sources within one laboratory resulted in highly significant differences. Based on this study, the International Fishmeal and Fish Oil Organization has adopted this new method, using 0.0002% pepsin but keeping the AOAC method of calculation. The type of shaker and source of pepsin are recommended but are not mandatory. The repeatability and reproducibility limits of this new method are 1.6 and 3.3% units of solubility, respectively.
 ...
PMID:Determination of nitrogen solubility in dilute pepsin hydrochloric acid solution of fishmeal: interlaboratory study. 1247 2

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.
 ...
PMID:Conversion of the nitrogen content in liquid manure into biomass and polyglutamic acid by a newly isolated strain of Bacillus licheniformis. 1258 95

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.
 ...
PMID:Enhanced production of pectinase by Bacillus sp. DT7 using solid state fermentation. 1261 48

Because in the phloem sap of maize (Zea mays L.) leaves a quarter of the total amino nitrogen can be found as alanine, the capacity of a de novo synthesis of alanine from 3-phosphoglycerate (3-PGA) was studied with isolated bundle sheath (BS) strands of maize. Inasmuch as these cells have retained their plasmodesmatic openings, it was possible to study the formation of alanine from 3-PGA when glutamate and ADP were being added. Alanine synthesis required the existence of the intact cell structure. From the formation of the intermediates, partially released to the medium, the activities of the enzymes of the reaction chain from 3-PGA to alanine could be measured in the intact cells. The results show that in the BS cells the rate of alanine production from pyruvate (0.5 micromole/minute per milligram BS chlorophyll) is more than sufficient to produce one-fourth of the assimilated nitrogen as alanine. As the activity of pyruvate kinase in intact bundle sheath cells in the light was found to be only 0.2 micromole/minute per milligram BS chlorophyll, it is concluded that in the light part of the conversion of 3-PGA to pyruvate may not occur via pyruvate kinase reaction, but via phosphoeno/pyruvate carboxylase, NADP-malate dehydrogenase, and NADP-malic enzyme in the mesophyll and BS cells.
 ...
PMID:Alanine synthesis by bundle sheath cells of maize. 1666 62

Surface hydrolysis of polyester scaffolds is a convenient technique suggested to promote protein adsorption for improving cell attachment. We have, therefore, investigated the effect of hydrolysis of polyester surfaces for protein adsorption to clarify the conditions needed. Three polyesters, poly(ethylene terephthalate) (PET), poly(lactic acid) (PLA), and poly(glycolic acid) (PGA), were selected. Adsorption was investigated by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and quartz crystal microbalance (QCM). Hydrolyzed PET adsorbed significantly more proteins than nonhydrolyzed. Degradable polymers adsorbed at higher rates when the polymers were hydrolyzed prior to adsorption, but the same amount as nonhydrolyzed, suggesting spontaneous hydrolysis during the adsorption. XPS shows that hydrolysis prior to absorption for PET results in a surface nitrogen composition of approximately 14%, similar to pure protein (16%). Nonhydrolyzed PET surfaces showed only approximately 7% nitrogen, indicating protein layers thinner than approximately 10 nm. Adsorption to PLA and PGA shows nitrogen contents of 14-15% in both cases. SEM revealed striking differences in morphology of the protein coating. Hydrolyzed or spontaneously hydrolyzable surfaces display a pronounced fibrous structure while nonhydrolyzed surfaces give smooth structures. In combination, the results show that surface hydrolysis increase adsorption rate, but not the amount of proteins on polyesters that degrades in vivo. Surface treatment of nondegradable polyester increases the total amount of proteins and induces the formation of fibrous protein structures. Post hydrolysis treatment by acetic acid, replacing the counter-ion to a proton, further enhances protein attachment. Finally, cell attachment experiments verifies that protein adsorption increase the cell attachment to polyester surfaces.
 ...
PMID:Protein adsorption onto polyester surfaces: is there a need for surface activation? 1668 Jun 92

A strain with high poly-gamma-glutamic acid (gamma-PGA) production was isolated from fermented bean curd, a traditional Chinese food. The strain was named Bacillus subtilis ZJU-7 according to 16s rDNA sequencing and its taxonomic characters. The culture conditions for gamma-PGA production were evaluated. The most suitable carbon and nitrogen sources were sucrose and tryptone, respectively. Exogenous L-glutamic acid was necessary for gamma-PGA production, and the production of gamma-PGA increased on the addition of L-glutamic acid to the medium. In the medium containing 60 g/L of sucrose, 60 g/L of tryptone, 80 g/L of L-glutamic acid, and 10 g/L of NaCl, the yield of gamma-PGA reached 54.4 g/L after cultivation at 37 degrees C for 24 h, which was the highest gamma-PGA production compared with values reported in the literature. The average molecular mass of gamma-PGA produced was about 1.24 x 106 Daltons. B. subtilis ZJU-7 is genetically stable and can synthesize levan instead of gamma-PGA without the addition of L-glutamic acid to the medium.
 ...
PMID:Efficient production of poly-gamma-glutamic acid by Bacillus subtilis ZJU-7. 1672 Sep 7

Pepsin B is known to be distributed throughout mammalia, including carnivores. In this study, the proteolytic specificity of canine pepsin B was clarified with 2 protein substrates and 37 synthetic octapeptides and compared with that of human pepsin A. Pepsin B efficiently hydrolyzed gelatin but very poorly hydrolized hemoglobin. It was active against only a group of octapeptides with Gly at P2, such as KPAGF/LRL and KPEGF/LRL (arrows indicate cleavage sites). In contrast, pepsin A hydrolyzed hemoglobin but not gelatin and showed high activity against various types of octapeptides, such as KPAEF/FRL and KPAEF/LRL. The specificity of pepsin B is unique among pepsins, and thus, the enzyme provides a suitable model for analyzing the structure and function of pepsins and related aspartic proteinases. Because Tyr13 and Phe219 in/around the S2 subsites (Glu/Ala13 and Ser219 are common in most pepsins) appeared to be involved in the specificity of pepsin B, site-directed mutagenesis was undertaken to replace large aromatic residues with small residues and vice versa. The Tyr13Ala/Phe219Ser double mutant of pepsin B was found to demonstrate broad activity against hemoglobin and various octapeptides, whereas the reverse mutant of pepsin A had significantly decreased activity. According to molecular modeling of pepsin B, Tyr13 OH narrows the substrate-binding space and a peptide with Gly at P2 might be preferentially accommodated because of its high flexibility. The hydroxyl can also make a hydrogen bond with nitrogen of a P3 residue and fix the substrate main chain to the active site, thus restricting the flexibility of the main chain and strengthening preferential accommodation of Gly at P2. The phenyl moiety of Phe219 is bulky and narrows the S2 substrate space, which also leads to a preference for Gly at P2, while lowering the catalytic activity against other peptide types without making a hydrogen-bonding network in the active site.
 ...
PMID:Roles of Tyr13 and Phe219 in the unique substrate specificity of pepsin B. 1712 81

This work reports on the optimization of PGA production by Bacillus licheniformis NCIM 2324 in solid state fermentation (SSF). In the first step, the one factor-at-a-time method was used to investigate the effect of solid substrates, initial moisture content, pH, and additional carbon and nitrogen source on PGA production; subsequently, response surface methodology (RSM) was used to establish the optimum concentrations of the key nutrients for higher PGA production. In the second step, the effects of amino acids and TCA cycle intermediates on the production of PGA were studied. The final optimized medium gave a maximum yield of 98.64 +/- 1.61 mg gds(-1) of PGA, which is significantly higher than that reported in the literature.
 ...
PMID:Enhanced production of poly (gamma-glutamic acid) from Bacillus licheniformis NCIM 2324 in solid state fermentation. 1865 8

Poly-gamma-glutamic acid (gamma-PGA) is a kind of water-soluble and biodegradable polymer made from D- and L-glutamic acid units, which are linked by amide bonds formed between alpha-amino and gamma-carboxylic acid groups. As a potential targeted biopolymer that can be refined from biomass directly, gamma-PGA has been increasingly applied to food, cosmetic, and pharmaceutical industries. In this work, a suitable nitrogen source was screened out for the high and cost-effective production of gamma-PGA in Bacillus subtilis ZJU-7. The effects of inoculation time and initial glucose concentration on the gamma-PGA production were investigated systematically in both shake flasks and a bench-top 15-l fermentor. Under the optimized culture conditions, a high gamma-PGA productivity (46.4 g/l) was obtained after 48 h cultivation at 37 degrees C. Finally, the large-scale fermentation of gamma-PGA production was successfully scaled up to a 100-l fermentor, with the highest gamma-PGA productivity for over 54.0 g/l.
 ...
PMID:Effects of cultivation conditions on the production of gamma-PGA with Bacillus subtilis ZJU-7. 1866 74

This paper reports on the optimization of poly(gamma-glutamic acid) (PGA) production by Bacillus licheniformis NCIM 2324 using a statistical approach. One-factor-at-a-time method was used to investigate the effect of carbon sources, nitrogen sources and pH on PGA production. Plackett-Burman design was adopted to select the most important nutrients influencing the yield of PGA. After identifying effective nutrients, response surface methodology was used to develop a mathematical model to identify the optimum concentrations of the key nutrients for higher PGA production, and confirm its validity experimentally. PGA production increased significantly from 5.27 to 26.12 g/l when the strain was cultivated in the optimal medium developed by using statistical approach, as compared to basal medium.
 ...
PMID:A statistical approach to optimization of fermentative production of poly(gamma-glutamic acid) from Bacillus licheniformis NCIM 2324. 1867 41


<< Previous 1 2 3 4 Next >>