Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0267964 (PAA)
 2,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two weak poly(acid)s, poly(acrylic acid) (PAA) and poly(N-acryloyl-glycine) (P1), were graft-copolymerized onto porous cellulose membrane and their protonation behavior in aqueous media was studied by potentiometric techniques. Comparison with the corresponding free polymers in solution showed the same basicity constants during the protonation of ionized carboxyl groups, and the large potentiometric hysteresis loops observed for the grafts were indicative of specific interactions with the cellulose substrate. This was confirmed by FT-IR spectroscopic analysis at low pH. The polymeric membrane system, containing immobilized glucose oxidase, was synthesized for the purpose of insulin delivery in response to glucose concentration. The porosity of the membrane was controlled by the charge-state conformations of the grafted chains. The formation of gluconic acid in the presence of glucose caused a drop in pH which led to neutralization of the negatively charged carboxyl groups. The decrease in electrostatic repulsion caused the extended macromolecular chain to assume a coil-like form and opened the membrane pores to insulin.
 ...
PMID:An insulin-releasing system responsive to glucose: thermodynamic evaluation of permeability properties. 175 61

1. In order to observe and compare the withdrawal phenomena which follow treatment with the beta-adrenoceptor blocking drugs, bopindolol (with partial agonist activity PAA) and atenolol (without PAA), two groups of six normal volunteers were studied before, during and after 16 days drug administration. 2. Measurements of plasma levels of cortisol, prolactin, insulin, noradrenaline, adrenaline, glucose and potassium were made during a pre-treatment baseline period, on maximum dose and for 21 days after drug withdrawal. Isoprenaline infusions were given to determine sensitivity of heart rate responses and haemodynamic changes measured in response to physiological manoeuvres. 3. Following atenolol withdrawal the results show hormonal evidence of adrenergic overactivity in the form of elevation of plasma cortisol, insulin and glucose levels. After bopindolol withdrawal there was, in contrast, an overshoot of plasma prolactin and a persistent elevation of plasma potassium and adrenaline post-isoprenaline. 4. The hormonal changes which follow withdrawal of atenolol and bopindolol are associated with haemodynamic changes reported elsewhere (Walden et al., 1990). 5. These observations provide confirmatory evidence of a post beta-adrenoceptor blockade withdrawal syndrome which differs between the two drugs studied and this may reflect the properties of the drugs, in particular the PAA of bopindolol.
 ...
PMID:Withdrawal phenomena after atenolol and bopindolol: hormonal changes in normal volunteers. 198 17

Fermentation parameters for the production of penicillin G acylase by Escherichia coli NCIM 2400 have been evaluated. The bacterium produced the enzyme intracellularly when grown in nutrient broth containing PAA. PAA stimulated the enzyme synthesis by 8-10 fold and reduced the lag period. The optimum concentration of PAA for induction was 20 mM and addition of PAA prior to inoculation gave maximum production of PGA. Glucose, lactose, sorbitol, acetate and lactate even at 0.1% concentration catabolically repressed the enzyme formation. Peptone was the best utilised 'N' source for the enzyme production. Phosphate and yeast extract were found to be essential for both the growth and for enzyme biosynthesis. Temperature between 22-24 degrees C was optimum and under ideal condition E. coli NCIM 2400 produced 0.45-0.55 U/ml of penicillin G acylase.
 ...
PMID:Biosynthesis of benzylpenicillin acylase by Escherichia coli NCIM-2400. 269 12

The present study was designed to evaluate the urinary albumin excretion in 62 patients with essential hypertension. None of them had prior proteinuria or history of nephropathy or uropathy. Patient data, blood pressure, proteinuria using Bradford's method, albuminuria by radial immunodiffusion, urinary SDS-PAA electrophoresis, plasma glucose, serum creatinine, serum cholesterol were determined. The urinary albumin excretion was significantly higher (p < 0.001) in the group of hypertensive patients (19.22 +/- 2.36 micrograms/min) compared to a group of 20 control subjects (4.17 +/- 0.67 microgram/min). Compared to a subgroup of hypertensive patients without ischemic heart disease (12.07 +/- 1.30 micrograms/min) microalbuminuria was higher (43.74 +/- +/- 5.74 micrograms/min; p < 0.001) in a subgroup of 14 patients with essential hypertension and ischemic heart disease with severe coronary events: unstable angina pectoris (9 patients), myocardial reinfarction (2 patients), ventricular arrhythmias (3 patients). A positive correlation between the microalbuminuria and the duration of hypertension was found (r = 0.64; p < 0.001). Therefore, microalbuminuria may represent a marker of the severity of vascular involvement in hypertensive patients.
 ...
PMID:Microalbuminuria in hypertensive patients. 808 6

A strategy of genetically manipulating carbon assimilation with respect to expression of the pac gene was employed for overproduction of recombinant penicillin acylase (PAC). Two expression plasmids of pCLL2902 and pCLL3201, which contain the pac coding region but differ in the pac regulatory region, were constructed for the production experiments. Expression of the pac gene was subjected to phenyl acetic acid (PAA-) induction and glucose catabolite repression for pCLL3201, whereas it was subjected to neither of the two transcriptional regulations for pCLL2902. The specific PAC activity for strains harboring pCLL2902 was significantly higher than that for strains harboring pCLL3201 due to an improved transcription efficiency. In addition, no inclusion bodies were observed upon production of PAC using the current expression systems. The results suggest that using the native pac promoter instead of a strong promoter such as tac for regulation is a feasible approach for production of PAC. The impact of the current expression systems is also significant from a process viewpoint since, using strains harboring pCLL2902, not only could glucose replace PAA as a carbon source of Escherichia coli cultures for production of PAC but also the volumetric PAC activity was highly improved.
 ...
PMID:Manipulation of carbon assimilation with respect to expression of the pac gene for improving production of penicillin acylase in Escherichia coli. 1020 Nov 13

Conjugation of proteins to copolymers from poly(acrylic acid) grafted onto PEO-PPO-PEO backbone (Pluronic-PAA) following adsorption of the conjugates onto hydrophobic surfaces is reported. Insulin-Pluronic-PAA conjugates show negligible internalization of insulin into human uterine smooth muscle cells as well as enhancement of mitogenic activity. Glucose-induced release of glycated albumin complexed with a Pluronic-PAA-concanavalin conjugate and adsorbed onto polystyrene nanospheres may provide a model for a glucose-responsive protein delivery system or a heterogeneous diagnostic device.
 ...
PMID:Bioactive surfaces via immobilization of self-assembling polymers onto hydrophobic materials. 1041 66

In this paper we show that hyperbranched polymers can be used as a host matrix for electrostatic entrapment of enzymes. Specifically, amine-functionalized glucose oxidase (GOx+) and horseradish peroxidase, as well as poly(amidoamine) dendrimer-modified horseradish peroxidase, reversibly sorb into polyanionic, hyperbranched poly(sodium acrylate) (PAA-) films that are on the order of a few hundred angstroms thick. The quantity of GOx+ entrapped within the PAA- films depends on the nature of film preparation but is typically on the order of 0.06 unit/cm2. The extent to which entrapped GOx+ retains its activity depends on the film history, but for PAA-/GOx+ composites not exposed to glucose and stored at 4 degrees C, the original activity is retained for up to 68 days and perhaps longer.
 ...
PMID:Electrostatic immobilization of glucose oxidase in a weak acid, polyelectrolyte hyperbranched ultrathin film on gold: fabrication, characterization, and enzymatic activity. 1045 Jan 59

Layer-by-layer supramolecular structures composed of alternate layers of negatively charged enzymes and cationic redox polyelectrolyte have been assembled. Glucose oxidase (GOx), lactate oxidase (LOx) and soybean peroxidase (SBP) have been electrically wired to the underlying electrode by means of poly(allylamine) with [Os(bpy)2ClPyCOH]+ covalently attached (PAA-Os) in organized structures with high spatial resolution. Biotinylated glucose oxidase has also been used to assemble step-by-step on antibiotin goat immunoglobulin (IgG) layers and the enzyme was electrically wired by PAA-Os. These spatially organized multilayers with mono- and bienzymatic schemes can work efficiently in molecular recognition, redox mediation and generation of an electrical signal. The concentration of redox mediator integrated into the multilayers, obtained from the voltammetric charge and an estimation of the layer thickness, exceeds by 100-fold the amount of deposited enzyme assessed by quartz crystal microbalance. Differences in GOx electrical wiring efficiency have been detected with the different assembling strategies. The surface concentration of electrically wired enzyme represents a small proportion of all the enzyme molecules present in the multilayers which can be oxidized by the soluble mediator [Os(bpy)2Cl PyCOOH]Cl. This proportion, as well as the rate of FADH2 oxidation by PAA-Os, increases with the number of electrically wired enzyme layers and with the spatial accessibility of the Os moiety to the enzyme active center.
 ...
PMID:Layer-by-layer electrostatic deposition of biomolecules on surfaces for molecular recognition, redox mediation and signal generation. 1119 90

The uptake of glucose oxidase (GOx) onto a polycationic redox polymer (PAA-Os)-modified surface, by adsorption from dilute aqueous GOx solutions, was followed by the quartz crystal microbalance (QCM) and shows double exponential kinetics. The electrochemistry of the layer-by-layer-deposited redox-active polymer was followed by cyclic voltammetry in glucose-free solutions, and the enzyme catalysis mediated by the redox polymer was studied in beta-D-glucose-containing solutions. AFM studies of the different layers showed the existence of large two dimension enzyme aggregates on the osmium polymer for 1 microM GOx and less aggregation for 50 nM GOx solutions. When the short alkanethiol, 2,2'-diaminoethyldisulfide was preadsorbed onto gold, a monoexponential adsorption law was observed, and single GOx enzyme molecules could be seen on the surface where the enzyme was adsorbed from 50 nM GOx in water.
 ...
PMID:Layer-by-layer self-assembly of glucose oxidase and Os(Bpy)2CIPyCH2NH-poly(allylamine) bioelectrode. 1130 46

Non-covalent molecular imprinting of poly(allylamine hydrochloride) (PAA HCl) with glucose phosphate mono-sodium salt produced molecularly imprinted polymer (MIP) hydrogels capable of quantitative, isomerically specific binding of glucose. By ionic association of a template molecule, glucose phosphate mono-sodium salt, to the polymer prior to covalent crosslinking, MIP hydrogels were created with an affinity for binding glucose. In this study we have synthesized MIPs using epichlorohydrin, ethylene glucol diglycidyl ether, and glycerol diglycidyl ether as crosslinkers in order to evaluate their effectiveness with respect to molecular imprinting for glucose. MIP hydrogels were also synthesized with the different crosslinkers and varying amounts of the template molecule in an attempt to elucidate the impact of imprint quantities on the effectiveness of the imprinting technique. Batch equilibration studies, using each of the MIPs and similar non-molecularly imprinted polymers were performed to determine their binding capacities with respect to glucose and fructose. The binding capacity data are discussed and employed in the evaluation of the specificity imparted by the imprinting procedure. MIP hydrogels with binding capacities in excess of 0.5 g of glucose per gram of dried gel were synthesized. Isomeric specificity in hydrogels imprinted for glucose was demonstrated by higher binding capacities of glucose than those of fructose in the same polymers.
 ...
PMID:Molecularly imprinted polymer hydrogels displaying isomerically resolved glucose binding. 1137 47


1 2 3 4 5 6 Next >>