Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

p- and o-Aminomethamphetamine were synthesized as haptens to be coupled with carrier protein at the benzene ring of methamphetamine. Immunogens were prepared by the glutaraldehyde method or the MBS (N-(m-maleimidobenzoyloxy)succinimide) type cross-linking reagent method. In particular, immunization with p-aminomethamphetamine-bovine serum albumin (BSA) conjugate prepared by the glutaraldehyde method gave an anti-methamphetamine antiserum having a low cross-reactivity with methylephedrine. With the antiserum, three kinds of immunoassays for methamphetamine were established. An enzyme immunoassay (EIA) and an enzyme-linked immunosorbent assay (ELISA) were developed with alkaline phosphatase (ALP) as a label enzyme. The amount of antibody bound ALP conjugate was determined by its activity in dephosphorylating p-nitrophenyl phosphate in EIA and nicotinamide adenine dinucleotide phosphate (NADP+) in ELISA. The range of methamphetamine measurable by ELISA was 0.025-0.5 ng/well and its sensitivity was superior to that of EIA (0.3-300 ng/tube). A latex agglutination inhibition reaction test (LAIRT) was also developed for the mass screening method of urine samples. The sensitivity of this method for methamphetamine was 0.1 micrograms/ml urine.
 ...
PMID:Immunoassay for methamphetamine with a new antibody. 218 Jul 98

N-Arylazido-beta-alanyl-NAD+ [N3'-O-(3-[N-(4-azido-2-nitrophenyl)amino]propionyl)NAD+] has been prepared by alkaline phosphatase treatment of arylazido-beta-alanyl-NADP+ [N3'-O-(3-[N-(4-azido-2-nitrophenyl)amino]propionyl)NADP+]. This NAD+ analogue was found to be a potent competitive inhibitor (Ki = 1.45 microM) with respect to NADH for the purified bovine heart mitochondrial NADH dehydrogenase (EC 1.6.99.3). The enzyme was irreversibly inhibited as well as covalently labeled by this analogue upon photoirradiation. A stoichiometry of 1.15 mol of N-arylazido-beta-alanyl-NAD+ bound/mol of enzyme, at 100% inactivation, was determined from incorporation studies using tritium-labeled analogue. Among the three subunits, 0.85 mol of the analogue was bound to the Mr = 51,000 subunit, and each of the two smaller subunits contained 0.15 mol of the analogue when the dehydrogenase was completely inhibited upon photolysis. Both the irreversible inactivation and the covalent incorporation could be prevented by the presence of NADH during photolysis. These results indicate that N-arylazido-beta-alanyl-NAD+ is an active-site-directed photoaffinity label for the mitochondrial NADH dehydrogenase, and are further evidence that the Mr = 51,000 subunit contains the NADH binding site. Previous studies using A-arylazido-beta-alanyl-NAD+ [A3'-O-(3-[N-(4-azido-2-nitrophenyl)amino]propionyl)NAD+] demonstrated that the NADH binding site is on the Mr = 51,000 subunit [Chen, S., & Guillory, R. J. (1981) J. Biol. Chem. 256, 8318-8323]. Results are also presented to show that N-arylazido-beta-alanyl-NAD+ binds the dehydrogenase in a more effective manner than A-arylazido-beta-alanyl-NAD+.
 ...
PMID:N-arylazido-beta-alanyl-NAD+, a new NAD+ photoaffinity analogue. Synthesis and labeling of mitochondrial NADH dehydrogenase. 234 Feb 77

As food in the intestine "drives" the enterohepatic circulation and bile acids influence bile flow, we postulated that the cholestasis of total parenteral nutrition might be due to bile acid changes, and the cholelithiasis and biliary sludge of total parenteral nutrition to bile lipid changes. We therefore studied bile acid and bile lipid metabolism in the following groups of rats, with and without bile fistula: (a) nonfasted, orally fed controls, (b) orally fed controls fasted for 20 h, and (c) after 7 days of total parenteral nutrition. Biliary bile acid concentration (35.4 +/- 2.5 mM) and secretion (253 +/- 20.0 mumol/100 g body wt.24 h) increased significantly in the rats on TPN and the rats fasted for 20 h (38.8 +/- 2.5 and 243 +/- 23.4 mM, respectively) when compared with the orally fed controls (26.5 +/- 2.5 and 178 +/- 23.5 mM, respectively). Bile flow, however, was unchanged. Bile acid pool size (Eriksson washout technique) also increased from 43.4 +/- 3.0 mumol/100 g body wt in the controls to 50.5 +/- 4.8 in the group fasted for 20 h and 65.6 +/- 5.3 in the TPN group (p less than 0.05-0.01). Similar bile acid pool sizes (carcass extraction method) were found in the nonfistulated animals. Biliary cholesterol secretion and saturation were significantly less in the TPN rats than in the other two groups. Liver microscopy indicated only minimal fatty change, but serum bile acid and alkaline phosphatase levels were increased in the TPN group (p less than 0.05). Thus, during TPN bile acids stagnate within the enterohepatic circulation, increasing biliary bile acid concentration and secretion rates and expanding the pool size. However, the absence of an associated choleresis, together with abnormal liver function tests, suggest that alterations in bile acid metabolism cause a relative cholestasis in this model.
 ...
PMID:Cholestasis of total parenteral nutrition: bile acid and bile lipid metabolism in parenterally nourished rats. 249 12

Enzyme amplification has been applied to improve the sensitivity of many immunoassays which use alkaline phosphatase as the label. The activity of the enzyme is amplified by using NAD, derived by hydrolysis of NADP, to activate catalytically a substrate cycle that generates a coloured product. In routine use, an amplification factor of 100-fold is easily achieved and, with longer incubation times, this can be increased to allow the detection of as few as 3,000 enzyme molecules. In order to avoid the limitations of spectrophotometry, an electrochemical version of the amplifier has recently been developed which performs with comparable sensitivity in a prototype device. The many advantages of electrochemical detection may ultimately herald the arrival of a new generation of simple, sensitive and inexpensive diagnostic systems.
 ...
PMID:Enzyme amplified immunoassays. 255 97

A recycling assay for alkaline phosphatase, based on its ability to hydrolyse NADP to NAD+, is presented. The product NAD+ is recycled in a coupled assay consisting of NADH regeneration and reduction of a nitroblue tetrazolium salt. This assay is 10-12 times more sensitive than the conventional assay. We demonstrate the role of energy poisons in transport of this protein into the periplasm by combining the improved detection with phase separation of the periplasmic and cytoplasmic alkaline phosphatase pools.
 ...
PMID:A recycling assay for alkaline phosphatase applied to studies on its transport in E. coli K12. 269 14

A method is described for the serotyping of rotaviruses directly from samples of faeces. Serotype-specific monoclonal antibodies were used in a solid phase enzyme-immunoassay utilising a novel substrate system based on the de-phosphorylation of NADP, followed by cyclic colour reaction. This method is shown to be approximately 5-10 times more specific and sensitive than assays utilising a conventional substrate for alkaline phosphatase, and allowed serotypes to be ascribed to samples which could not be typed by other methods. The value of this method for rotavirus epidemiology and vaccine trials is discussed.
 ...
PMID:Serotyping of rotavirus by NADP-enhanced enzyme-immunoassay. 282 2

Within the uterine glands, the following enzymes were demonstrated by histochemical methods after 30, 58, 80, 100, and 110 d of pregnancy, respectively: beta-N-acetyl-hexosaminidase, beta-galactosidase, beta-glucuronidase, alpha-mannosidase, acid phosphatase, alkaline phosphatase, esterases, cytochrome oxidase, 5-nucleotidase, leucine aminopeptidase, adenosine triphosphatase, diaphorases (NADH, NADPH), glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, succinate dehydrogenase, isocitrate dehydrogenase (NAD, NADP), beta-hydroxybutyrate dehydrogenase, glycero-3-phosphate dehydrogenase, NAD-glycero-3-phosphate dehydrogenase, glutamate dehydrogenase (NAD, NADP), lactate dehydrogenase. The results show that the activities of G-6-PDH, 6-PGDH, and cytochrome oxidase increase within secreting cells during the 2nd half of pregnancy. The activities of the other enzymes remained almost unchanged during the period of investigation. The description of our results distinguishes between gland neck, middle, and distal part of the secretory unit, respectively. In general, the enzyme activities are similar within the middle and distal gland segments, but lower in the epithelia of the neck region. The activity of dehydrogenases was medium to intensive within the middle and distal gland segments, but only low to medium within the neck portion. Of the hydrolases, the acid phosphatase, ATPase, leucine aminopeptidase, and beta-galactosidase demonstrated an intensive activity within activity secreting cells. The enzyme activities of the gland epithelia are compared with these of the uterine surface epithelia and the histochemical results are discussed in context with their significance in histiotrophic nutrition.
 ...
PMID:[Enzyme histochemistry of the pig placenta. III. Histotopics of enzymes in the uterine epithelium]. 309 49

This communication presents the results obtained in tubular aggregates of 24 enzyme histochemical techniques for demonstrating activity of oxidoreductases, transferases, hydrolases and isomerases. The activity characteristics of the tubular aggregates in m. gluteus medius of 18 patients with diseases of the neuromuscular system were almost identical. A high activity of the mitochondrial enzymes, NADPH: tetrazolium oxidoreductase, NADH:tetrazolium oxidoreductase and cytochrome c oxidase, could be shown in the pathological structures, whereas the activity of the mitochondrial enzymes, glycerol-3-phosphate:menadione oxidoreductase, succinate:PMS oxidoreductase, malate:NAD+ oxidoreductase and isocitrate:NAD+ oxidoreductase, and the partial mitochondrial enzymes, malate:NADP+ oxidoreductase and isocitrate:NADP+ oxidoreductase, was very slight or even absent. There was a moderate to strong activity of the glycolytic enzymes lactate:NAD+ oxidoreductase, glyceraldehyde-3-phosphate:NAD+ oxidoreductase, phosphofructokinase, phosphoglucomutase and glucose phosphate isomerase. In contrast, the activity of alpha-glucan phosphorylase was slight. The activity of phosphogluconate:NADP+ oxidoreductase, glucose-6-phosphate:NADP+ oxidoreductase and 5'-nucleotidase was slight, whereas there was no activity of myosin ATPase and mitochondrial ATPase, acid phosphatase or alkaline phosphatase. The high activity of AMP-deaminase was very striking. The activity of peroxidase was moderate. Results obtained with adsorption studies point to adsorption of some of the enzymes studied to the tubular aggregates in vivo and this phenomenon very probably determined the histochemical characteristics of these structures.
 ...
PMID:Histochemical features of tubular aggregates in diseased human skeletal muscle fibres. 317 98

We have demonstrated that the purified guanine nine nucleotide exchange factor (GEF) may be isolated as a complex with NADPH. Complete inhibition of the GEF-catalyzed exchange of eukaryotic initiation factor 2-bound GDP for GTP was observed in the presence of either 0.5-0.75 mM NAD+ or NADP+. Incubation of GEF with ATP results in the phosphorylation of its Mr 82,000 polypeptide. This phosphorylation is strongly inhibited by heparin but is not affected by heme or H8 (N-[2-(methylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride), an inhibitor of cAMP- and cGMP-dependent protein kinases and protein kinase C. The purification of GEF was modified to eliminate any contaminating kinase activity and the isolated protein appears to be homogeneous as judged by NaDodSO4/polyacrylamide gel electrophoresis and silver staining. The Mr 82,000 subunit of GEF is phosphorylated only upon addition of ATP and casein kinase II. The extent of phosphorylation is approximately equal to 0.55 mol of phosphate per mol of GEF, and this results in a 2.3-fold increase in the guanine nucleotide exchange activity. Following treatment of the phosphorylated GEF with alkaline phosphatase, the activity of the protein is reduced by a factor of 5. Rephosphorylation of GEF increases its specific activity to that of the phosphorylated protein. The results of this study suggest that phosphorylation/dephosphorylation of GEF plays a role in regulating polypeptide chain initiation.
 ...
PMID:Phosphorylation of the guanine nucleotide exchange factor from rabbit reticulocytes regulates its activity in polypeptide chain initiation. 342 26

A method is described for increasing the response of enzyme immunoassays employing alkaline phosphatase as the label initiating 2 sequential catalytic reactions. First, NADP is dephosphorylated to produce NAD, which catalytically activates a specific redox-cycle involving the enzymes alcohol dehydrogenase and diaphorase. During each turn of the cycle 1 molecule of a tetrazolium salt is reduced to an intensely coloured formazan. The method is capable of detecting as little as 0.01 amol alkaline phosphatase, and when applied to an immunoassay for TSH a sensitivity (zero + 2.5 standard deviations) of 0.0013 mIU/l was obtained.
 ...
PMID:Enzyme amplification for immunoassays. Detection limit of one hundredth of an attomole. 351 23


<< Previous 1 2 3 4 5 6 Next >>