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

Gas vesicles, isolated from lysed Halobacterium halobium cells, gave an amino acid analysis which accounted for 78% of the weight, and the balance was mainly salt and water. One percent of tightly bound d-galactose was found, as well as 2% of phosphate that was not released by treatment which promotes beta-elimination, by hydrolytic release of the galactose, by carboxymethylation of lysine, or by alkaline phosphatase digestion. Only a trace of lipid was detected, and it appeared to have a polyisoprenoid structure. The vesicles were not solubilized by extremes of pH, by agents such as urea, guanidine hydrochloride, formic acid, and detergents, or by organic solvents. Succinylation and carboxymethylation gave partial dispersion, but the products were heterogeneous and of high molecular weight. The amino acid composition of vesicles was independent of fragment size. No band was obtained by polyacrylamide gel electrophoresis, with neutral, acidic, and alkaline systems, with or without sodium dodecyl sulfate and urea, before or after chemical modification. No amino terminus was detected. Electrofocusing of a vesicle dispersion showed a major component with a pI of 4.0 and an amino acid composition of the whole vesicles, and a minor band with pI 3.4 which had an amino acid composition different from whole vesicles. Vesicle protein was resistant to digestion by Pronase, trypsin, thermolysin, and papain. The precipitin reaction with rabbit antivesicle serum was not inhibited by galactose or inorganic phosphate. Succinylated and carboxymethylated vesicles cross-reacted with antivesicle serum. Cell lysates contained material which reacted with antiserum, but it was heterogeneous and mainly larger than 5 x 10(6) daltons. Material from nonvacuolated mutants reacted weakly with antiserum, but the amino acid composition of the precipitated antigen was different from that of vesicles and of soluble cross-reacting material from vacuolated cells.
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PMID:Analysis of Halobacterium halobium gas vesicles. 473 10

A diagonal-electrophoresis method for the selective purification of serine phosphate peptides was applied to tryptic, chymotryptic and peptic digests of oxidized ovalbumin. This method is based on the release of the phosphate group bound to serine by treatment with alkaline phosphatase on paper. The identified serine phosphate peptides were purified by paper electrophoresis at pH6.5 and 2.0, dephosphorylation with bacterial alkaline phosphatase, and paper electrophoresis at pH2.0 again, in that order. The presence of two groups of serine phosphate peptides was apparent from the amino acid composition. One group contained no lysine, cysteic acid, proline, leucine or isoleucine (sequence 1) and the other had all those amino acids (sequence 2). Further degradation with subtilisin of those peptides and ;dansyl'-Edman sequence analysis established their partial sequences. The proposed sequences are as follows (with ;SerP' representing serine phosphate): sequence 1, -Ala-Gly-Arg-Glu-Val-Val-Gly-SerP-Ala-Glu-Ala-Gly-Asp-Val-Ala-Ala-Ser-(Val,Glx(2),Ser,Phe)-Arg-; sequence 2, -Asp-Lys-Leu-Pro-Gly-Phe-Gly-Asp-SerP-Ile-Glx-Ala-Glx-CySO(3)H-Gly-(Thr,Ser,Val)-(Asp,His,Val)-. The partial sequence of one of the phosphopeptides, Asp-(Glu,Ile,SerP), reported by Flavin (1954) was used to establish the proposed sequence 2.
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PMID:An application of diagonal electrophoresis to the selective purification of serine phosphate peptides. Serine phosphate peptides from ovalbumin. 488 Nov 41

The s.c. administration of cortisol to hamsters (50 mg/kg body wt/day for 4 days) produces a significant increase in maltase sucrase, alkaline phosphatase and leucineaminopeptidase activity in intestinal mucosa. Lactase activity is unaffected by cortisol. Gamma-glutamyltranspeptidase activity increases slightly in females but remains unchanged in males. Cortisol causes increase in proline and glycine absorption without changing the absorption of lysine.
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PMID:The effect of cortisol on stimulation of enzymatic activity and absorption of amino acids in the small intestine of adult hamsters. 615 Jul 87

The effect of a single oral dose of endosulfan (5 mg/kg body weight) on the uptake of certain nutrients and brush-border enzymes has been studied in rat intestine. The uptake of glucose and alanine was elevated but that of leucine was decreased in endosulfan-fed rats. There was no change in the uptake of phenylalanine and lysine in insecticide-fed rats. The activities of brush-border sucrase and alkaline phosphatase were considerably increased while the activity of Na+ K+ ATPase was reduced in endosulfan-exposed animals. The leucine aminopeptidase activity was unaffected in pesticide-treated rats. There was a significant decrease in cellular LDH and GOT activities with no change in GPT activity. Neither was there a considerable increase in the cellular glucose-6-phosphatase activity (P less than 0.01) in the pesticide-fed rats. These results suggest that endosulfan toxicity induces certain functional changes in the intestine.
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PMID:Effect of a single oral dose of endosulfan on intestinal uptake of nutrients and on brush-border enzymes in rats. 618 May 24

D- and L-amino acids (arginine, lysine) and hydroxylated molecules (sorbitol, ethyl-ethanolamine), all of which increase the intestinal transfer of calcium, are phosphorylated by jejunal and ileal microvilli. All these molecules inhibit the endogenous phosphorylation of microvilli proteins. D- and L-valine, which are not phosphorylated in the same conditions, have no effect on the phosphorylation of microvilli proteins. These observations are in good agreement with the scheme previously proposed for the increase of calcium intestinal transfer by L-lysine: phosphorylation of L-lysine by mucous membrane may interfere with that of membrane proteins, the phosphorylation of which would lower the permeability to that cation. Autoradiographies of the electrophoretogram show that the principal phosphorylable microvilli proteins have the same electrophoretic properties as those of the dimer and the monomer of alkaline phosphatase from the same intestinal loci. The ability of the enzyme to be phosphorylated and its well-known transphosphorylating activity upon hydroxylated molecules suggest that it could, in different ways, affect intestinal transfer of calcium.
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PMID:Enterocyte microvillus can phosphorylate molecules which inhibit endogenous phosphorylation of its proteins. 620 86

The circular dichroism bands of (+) gossypol in the spectral region 300-400 nm have been shown to be sensitive to interactions with proteins. Using CD spectroscopy, gossypol has been shown to interact with lactate dehydrogenase, malate dehydrogenase, alkaline phosphatase, lysozyme, protamine and poly-L-lysine. Binding to proteins generally results in a pronounced red shift of the long wavelength CD band (approximately 380-430 nm) accompanied by a reduction in ellipticity. The changes in spectral parameters of the 1Lb binaphthyl transition may reflect a distortion from a nearly perpendicular gossypol conformation, on binding to proteins.
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PMID:A circular dichroism study of (+) gossypol binding to proteins. 674 22

A micro-ELISA for screening of antibodies from hybridoma cultures against surface antigens of human melanoma is described. The technique employs alkaline phosphatase-conjugated protein A and target cells attached to poly-L-lysine-coated microtiter plates. The micro-ELISA is equally sensitive as the radioimmunoassay. Mild glutaraldehyde treatment of cells did not lead to an appreciable loss of antigen activity. The fixed cells can be stored at 4 degrees C for at least 6 weeks. It is concluded that the ELISA is superior to the radioimmunoassay in the following aspects: (1) exclusion of radioactive hazards, (2) speed of performance, and (3) lower costs.
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PMID:Use of an enzyme-linked immunosorbent assay (ELISA) for screening of hybridoma antibodies against cell surface antigens. 678 Jun 27

A simple and rapid microenzyme-linked immunosorbent assay has been developed for determination of anti-poly(ADP-ribose) antibodies in humans using a combination of protein A-alkaline phosphatase conjugates and poly(ADP-ribose)-coated polyvinyl microplates. After a 1-h treatment of the plates with 100 microliters of poly L-lysine (PLL) solution (50 micrograms/ml), an aliquot of the solution containing 100 ng poly(ADP-ribose) (50 microliters) was added to the PLL-treated plates and evaporated at 37 degrees C overnight to facilitate the adherence of poly(ADP-ribose) to the plates. Nonspecific binding of diluted test sera from patients with systemic lupus erythematosus (SLE) or from normal individuals to the PLL-coated plates was minimized by exposure of the plates for 1 h to Tris-buffered saline (pH 7.4) containing 0.01% bovine serum albumin (BSA). This method was also applicable to the determination of anti-double-stranded DNA antibodies in humans. The present assay is advantageous over those reported so far as it saves time and antigen.
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PMID:A simple and rapid microenzyme-linked immunosorbent assay for antibodies to poly(ADP-ribose) in systemic lupus erythematosus. 714 14

The effect of vitamin C deficiency on the digestive and absorptive functions of the gut has been investigated in guinea pigs. The absorption of D-glucose was significantly elevated, but that of L-leucine, L-alanine and L-lysine considerably depressed in the intestine of scorbutic guinea pigs compared to controls. The intestinal transport of vitamin B12 was also diminished. Activities of sucrase and alkaline phosphatase on the brush border were enhanced, but that of leucine aminopeptidase markedly reduced in scorbutic animals compared to controls. Maltase activity was unaffected in vitamin C deficient animals. Chemical analysis of the brush borders isolated from scorbutic animals revealed a considerable decrease in membrane protein, total lipids, phospholipids, and free cholesterol contents compared to control animals. In vivo 2-(14)C-acetate incorporation into membrane lipids suggested that the observed decrease in lipid components of the scorbutic membranes is due to reduced synthesis. Administration of ascorbic acid to scorbutic animals ameliorated the intestinal aberrations observed in scurvy.
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PMID:Effect of vitamin C deficiency in guinea pigs on intestinal functions and chemical composition of brush border membrane. 730 86

Human placental alkaline phosphatase (EC 3.1.3.1) was inactivated by periodate-oxidized AMP. The inactivation showed saturation kinetics and could be partially prevented by the substrate AMP or the product inhibitor inorganic phosphate. Oxidized AMP was itself a substrate for this enzyme, with an apparent Km of 0.67 mM. The hydrolytic products of oxidized AMP were identified as oxidized adenosine hemiacetals. Oxidized AMP was also found to be a non-competitive inhibitor with respect to p-nitrophenyl phosphate, with identical Kis and Kii values of 0.15 mM. Our results indicate that oxidized AMP could combine with the enzyme to form a binary complex, followed by reaction with the proximal lysyl amino group to yield a Schiff base. The latter was reduced with NaBH4 and identified by t.l.c. The incorporation of only 1.5 molecules of oxidized [14C]AMP per enzyme subunit resulted in a complete inactivation of the enzyme. The modified enzyme showed higher apparent Km for the substrates and higher Ki for inorganic phosphate, but lower [32P]phosphate incorporation, than the native enzyme. These results support the conclusion that a lysine residue is involved in the phosphate-binding site of human placental alkaline phosphatase.
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PMID:Periodate-oxidized AMP as a substrate, an inhibitor and an affinity label of human placental alkaline phosphatase. 734 Aug 4


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