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
Query: UNIPROT:P00790 (
PGA
)
2,475
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Several ionic liquids were used as reaction media for penicillin G acylase catalysis. In all the assayed ionic liquids, [bmim]PF6 proved good media for
PGA
-catalyzed hydrolysis. A novel [bmim]PF6/water two-phase system is provided for 6-aminopenicillanic acid (APA) production, which will be more benefical than aquous batch systems used widely in industrial production of APA.
Bioprocess Biosyst Eng 2006
Dec
PMID:Penicillin acylase catalysis in the presence of ionic liquids. 1708 15
A useful route for the development of antitumour therapies is by creating improved methods for delivering therapeutic agents to tumour cells or subcellular compartments and increasing retention of drugs within target cells. In this study, we have characterized nanoparticle (NP) uptake and metabolism by DAOY cells, a human medulloblastoma cell line. NPs were formed from a novel polymer, poly (glycerol-adipate) (
PGA
), containing Rhodamine B Isothiocyanate (RBITC) as a fluorescent marker. It was observed that the cellular uptake of NPs depends on the incubation time and the concentration of NPs in the culture medium. The studies of retention and metabolism of NPs within cells indicated that 1) faster degradation of NPs within cells compared with that in cell culture medium in vitro; 2) a small fraction of NPs were recycled back to the outside of cell, whereas most NPs entered endosomes and lysosomes; and 3) recycled NPs were re-taken up in the following 2 h incubation time. These studies thus suggested that
PGA
NPs could be used for localising therapeutic agents into cells, and could provide prolonged drug effects because of their long sustained release in physiological conditions and their rapid release when taken up into cells.
J Control Release 2006
Dec
01
PMID:Uptake and metabolism of novel biodegradable poly (glycerol-adipate) nanoparticles in DAOY monolayer. 1711 18
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.
Biochemistry 2006
Dec
05
PMID:Roles of Tyr13 and Phe219 in the unique substrate specificity of pepsin B. 1712 81
The buildup of biodegradable poly(L-glutamic acid) (
PGA
) and poly(L-lysine) (PLL) multilayers on silica and titanium surfaces and the immobilization of enamel matrix derivate (EMD) protein was followed by utilizing in situ ellipsometry, quartz crystal microbalance with dissipation, and dual-polarization interferometry (DPI). The use of the relatively new DPI technique validated earlier published ellipsometry measurements of the PLL-
PGA
polypeptide films. The hydrophobic aggregating EMD protein was successfully immobilized both on top of and within the multilayer structures at pH 5.0. DPI measurements further indicated that the immobilization of EMD is influenced by the flow pattern during adsorption. The formed polypeptide-EMD multilayer films are of interest since it is known that EMD is able to trigger cell response and induce biomineralization. The multilayer films thus have potential to be useful as bioactive and biodegradable coatings for future dental implants.
Langmuir 2006
Dec
19
PMID:Immobilization of enamel matrix derivate protein onto polypeptide multilayers. Comparative in situ measurements using ellipsometry, quartz crystal microbalance with dissipation, and dual-polarization interferometry. 1715 85
Oxidative events that target the sugar-phosphate backbone of DNA can lead to reactive fragments that interfere with DNA repair, transcription and translation by the formation of cross-links and adducts of proteins and nucleobases. Here we report the formation of several such lesions through the aerobic degradation of an independently generated C-3'-thymidinyl radical in 2'-deoxyoligonucleotides. Individual fragments were identified by independent synthesis and comparison of retention times in high-performance liquid chromatography (HPLC) and/or matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-ToF MS) along with gel electrophoresis. The formation of this reactive intermediate in the presence of oxygen was found to produce 3'-phosphoglycolaldehyde (3'-
PGA
) as well as 3'-ketoenolether (3'-KEE), 3'-phosphoglycolate (3'-PG), and 5'-aldehyde terminated oligonucleotide fragments. Additionally, a significant outcome of C-3'-thymidinyl radical formation in DNA oligomers is a strand break resulting in one 3'- and two 5'-phosphate-terminated oligomers. These results suggest the involvement of several sugar derived reactive species upon C-3'-radical initiated scission of single-stranded DNA under aerobic conditions. The electrophilic nature of several of these products as well as their formation through a single oxidative event can make the presence of a C-3'-DNA radical more detrimental to the cell than products derived from more frequently occurring DNA sugar radicals.
Chem Res Toxicol 2006
Dec
PMID:Aerobic fate of the C-3'-thymidinyl radical in single-stranded DNA. 1717 76
The aqueous solution behaviour of polyethyleneimine (a cationic synthetic polymer) in the presence of anions (such as citrate and phosphate) was studied by means of turbidimetry. The variation of the absorbance at 420 nm of dilute mixture with pH, the polymer concentration and the ionic strength were examined. The mixture of polyethyleneinine citrate or polyethyleneinine phosphate behaves as a pseudo polyampholyte with an isoelectric point of 5.5 and 6.2 for phosphate and citrate respectively and a precipitation pH range between 3.5 and 8.0.
Pepsin
was completely precipitated with the polymer anion complex within this pH interval. Citrate showed a better precipitation effect than phosphate did. The precipitate was reversibly dissolved in NaCl (for concentrations higher than 0.2 M) and pepsin kept its biological activity. Studies of pepsin thermal stability (by differential scanning calorimetry) revealed that the polyethyleneimine presence increased the enzyme denaturation temperature. The circular dichroism spectrum of pepsin showed a non-significant loss of secondary and tertiary enzyme structure by the polyethyleneimine. However, the polymer presence increased the biological activity of pepsin.
J Chromatogr B Analyt Technol Biomed Life Sci 2007
Dec
01
PMID:Polyethyleneimine phosphate and citrate systems act like pseudo polyampholytes as a starting method to isolate pepsin. 1798 Nov 1
A study of the practical applications of the addition of paramagnetic spin relaxation (PSR) ions to a variety of polymers (PLL, PAA,
PGA
, PVP, and polysaccharides such as hyaluronic acid, chitosan, mannan, and dextran) in solution (D2O and DMSO-d6) is described. Use of Gd(III), Cu(II), and Mn(II) allows a reduction of up to 500% in the 1H longitudinal relaxation times (T1), and so in the time necessary for recording quantitative NMR spectra (sensitivity enhancement) neither an increase of the spectral line width nor chemical shift changes resulted from addition of any of the PSR agents tested. Selective suppression of the 1H and 13C NMR signals of certain components (low MW molecules and polymers) in the spectrum of a mixture was attained thanks to their different sensitivity [transverse relaxation times (T2)] to Gd(III) (PSR filter). Illustration of this strategy with block copolymers (
PGA
-g-PEG) and mixtures of polymers and low MW molecules (i.e., lactose-hyaluronic acid, dextran-PAA, PVP-glutamic acid) in 1D and 2D NMR experiments (COSY and HMQC) is presented. In those mixtures where PSR and CPMG filters alone failed in the suppression of certain components (i.e., PVP-mannan-hyaluronic acid) due to their similarity of 1H T2 values and sensitivities to Gd(III), use of the PSR filter in combination with CPMG sequences (PSR-CPMG filter) successfully resulted in the sequential suppression of the components (hyaluronic acid first and then mannan).
J Am Chem Soc 2007
Dec
12
PMID:Paramagnetic NMR relaxation in polymeric matrixes: sensitivity enhancement and selective suppression of embedded species (1H and 13C PSR filter). 1800 45
Prior studies suggest Staphylococcus aureus exotoxins are not produced when the organism is cultured in human blood. Human blood was fractionated into plasma and water-lysed red blood cells, and it was demonstrated that mixtures of alpha and beta globins of hemoglobin (as low as 1 mug/mL) inhibited S. aureus exotoxin production while increasing production of protein A and not affecting bacterial growth.
Pepsin
but not trypsin digestion destroyed the ability of alpha and beta globin to inhibit exotoxin production. Exotoxin production by both methicillin-resistant and methicillin-susceptible organisms was inhibited. Production of streptococcal pyrogenic exotoxin A by Streptococcus pyogenes was unaffected by alpha and beta globin chains but was inhibited when produced in S. aureus. Use of isogenic S. aureus strains suggested the targets of alpha and beta globin chains, leading to inhibition of staphylococcal exotoxins, included the two-component system SrrA-SrrB. delta hemolysin production was also inhibited, suggesting the two-component (and quorum sensing) system AgrA-AgrC was targeted. The alpha and beta globin chains represent promising molecules to interfere with the pathogenesis of serious staphylococcal diseases.
Biochemistry 2007
Dec
18
PMID:Alpha and beta chains of hemoglobin inhibit production of Staphylococcus aureus exotoxins. 1802 Apr 51
Soybean cake, a byproduct obtained during the processing of soybean oil, has been shown to be a rich source of isoflavones. The objectives of this study were to use soybean cake as raw material for processing into powder and to evaluate the anti-inflammatory activity. Eleven treatments, including powders of malonylglucoside, glucoside, acetylglucoside, aglycone, ISO-1, and ISO-2, as well as genistein standard, gamma-
PGA
, control, normal, and PDTC, were used for evaluation. A total of 77 mice were each provided daily with tube feeding for 4 weeks at a dose of 0.3 mL of aqueous solution from each treatment, and inflammation was induced with intraperitoneal injection of 1 mg/kg of body weight lipopolysaccharide (LPS). Results showed that all of the isoflavone powders and genistein standard were effective in inhibiting LPS-induced inflammation, lowering leukocyte number in mice blood and reducing production of IL-1beta, IL-6, NO, and PGE2 in both peritoneal exudate cell supernatant and peritoneal exudate fluid. All of the isoflavone treatments failed to retard T cell proliferation; however, both ISO-1 and ISO-2 could inhibit B cell proliferation. The difference in anti-inflammatory activity was minor between any of the isoflavone treatments.
J Agric Food Chem 2007
Dec
26
PMID:Anti-inflammatory effects of isoflavone powder produced from soybean cake. 1805 38
There is little published data on the incidence of eye disease in Asian patients with psoriasis. We determined the frequency of ocular complications in Singaporean Asian patients with chronic plaque psoriasis and related these to extent and severity of psoriasis, family history, treatment and presence of arthritis. A cross-sectional prevalence investigation was carried out in 100 patients who received a comprehensive eye examination. Psoriasis extent and severity was graded by the Lattice System Physician's Global Assessment (LS-PGA). Two patients (four eyes) had uveitis, one of whom had psoriatic arthritis (2% incidence). Presence or absence of uveitis correlated with mean LS-
PGA
scores. Sixty-three patients had cataract unrelated to previous steroid or phototherapy treatment; in younger (<50 years) patients they were commoner than in those with higher (>5) LS-
PGA
scores. Three eyes in two patients (2% prevalence) had glaucomatous optic neuropathy unrelated to previous treatment, and comparable with expected population frequency. These findings, although limited by lack of data from a comparable control population, suggest that eye complications are common in Asian patients with psoriasis and eye symptoms should be elicited during history taking. Besides signs and symptoms of eye disease, an LS-
PGA
score of more than 5 should prompt referral for ophthalmological examination.
J Dermatol 2007
Dec
PMID:Psoriasis and the eye: prevalence of eye disease in Singaporean Asian patients with psoriasis. 1807 5
<< Previous
1
2
3
4
5
6
7
8
9
10
Next >>