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: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intake of the essential amino acids, threonine, lysine and methionine by Ukrainian children of different height was studied. The processes of osteogenesis and phosphorus-calcium metabolism in rats with the above amino acids deficiency in the diet were also subjected to study. A direct correlation was established between intake of the amino acids under study and the height of schoolchildren. The deficiency of the amino acids in the diet of experimental animals contributed to the retardation of the growth, destructive changes, an increase in the content of hydroxyproline, a reduction of phosphomonoesterase-I activity in bones, and alterations in phosphorus-calcium metabolism.
...
PMID:[Effect of amino acid deficiency on bone tissue growth and formation]. 403 75

Different patterns of isozymes were obtained by starch-gel electrophoresis of alkaline phosphatase from Escherichia coli strains differing only by strA or ram mutations, or both, in the 30S ribosomal subunit. The isozyme spread was reduced in strA and increased in ram strains; this strictly parallels the restriction and enhancement of translational ambiguity produced by these mutations. Streptomycin present during growth had an effect similar to ram on both isozymes and ambiguity. The three isozymes analyzed have different N-terminal residues: aspartic acid, valine, and threonine. Different patterns of isozymes were also obtained in a wild-type strain through the specific action of exogenous arginine. A link between the mechanism of the effect of arginine and that of the ribosome is not obvious. The possibility is discussed that in both cases, although by different mechanisms, N-terminals are formed with different sensitivity to limited degradative attack.
...
PMID:Ribosomal alterations controlling alkaline phosphatase isozymes in Escherichia coli. 455 93

Four proteins, which have been designated A, B, C and D, have been purified from human parotid saliva. These proteins are the major constituents of parotid saliva which migrate rapidly to the anode in polyacrylamide electrophoresis at pH9.5. Gel filtration and polyacrylamide electrophoresis were employed in the purification procedures. After purification all four preparations were tested for homogeneity by electrophoresis at pH2.8 and 9.5, by isoelectric focusing in the pH range 3-10, by immunodiffusion, and by sedimentation in the analytical ultracentrifuge. None of the proteins showed significant activity in assays for amylase, acid and alkaline phosphatase, protease, lysozyme, ribonuclease, peroxidase, beta-glucuronidase, beta-galactosidase, iron-binding activity and esterase. No cross-reactions were detected with antisera specific for lactoferrin and 15 serum proteins. All four proteins were rich in glutamic acid, proline and glycine and were lacking completely the sulphur-containing amino acids. Proteins A and C contained no threonine or tyrosine. Carbohydrate could be demonstrated only in protein A at a concentration of 4% of the total protein.
...
PMID:Purification and partial characterization of four proteins from human parotid saliva. 500 93

Two new extracellular nucleases, nucleases SM1 and SM2, were purified from the culture fluid of S. marcescens kums 3958, a fresh clinical isolate. The purification was carried out by the following steps; ammonium sulfate precipitation, and DEAE-cellulose and Sephadex G-100 column chromatography. At the final step, nucleases SM1 and SM2 were purified about 3,700- and 1,000-fold, respectively. They were free from phosphomonoesterase and phosphodiesterase activities. The pIs were 8.1 and 7.5 for nucleases SM1 and SM2, respectively. The molecular weight was estimated to be 35,000 for both enzymes by SDS-polyacrylamide disc gel electrophoresis. The results of amino acid analyses showed that both the threonine and serine contents were higher in nuclease SM2 than in SM1. Furthermore, nuclease SM1 was more stable than nuclease SM2 at 4 degrees C. The other properties of the two enzymes were similar; pH optimum (8.0), Mg2+ or Mn2+ for activation, and inhibition by chemical reagents such as EDTA and pyrophosphate. No significant difference was found in base specificity between nucleases SM1 and SM2. Both enzymes specifically degraded double-stranded homopolymers, especially poly(I). poly(C), as well as yeast RNA and calf thymus DNA. They hardly degraded, however, single-stranded homopolymers such as poly(dA), poly(G), and poly(U).
...
PMID:Isolation and characterization of nucleases from a clinical isolate of Serratia marcescens kums 3958. 635 Feb 76

The regulation of kinase activity associated with insulin receptor by phosphorylation and dephosphorylation has been examined using partially purified receptor immobilized on insulin-agarose. The immobilized receptor preparation exhibits predominately tyrosine but also serine and threonine kinase activities toward insulin receptor beta subunit and exogenous histone. Phosphorylation of the insulin receptor preparation with increasing concentrations of unlabeled ATP, followed by washing to remove the unreacted ATP, results in a progressive activation of the receptor kinase activity when assayed in the presence of histone and [gamma-32P]ATP. A maximal 4-fold activation is achieved by prior incubation of receptor with concentrations of ATP approaching 1 mM. High pressure liquid chromatographic analysis of tryptic hydrolysates of the 32P-labeled insulin receptor beta subunit reveals three domains of phosphorylation (designated peaks 1, 2, and 3). Phosphotyrosine and phosphoserine residues are present in these three domains while peak 2 contains phosphothreonine as well. Thus, at least seven sites are available for phosphorylation on the beta subunit of the insulin receptor. Incubation of the phosphorylated insulin receptor with alkaline phosphatase at 15 degrees C results in the selective dephosphorylation of the phosphotyrosine residues on the beta subunit of the receptor while the phosphoserine and phosphothreonine contents are not affected. The dephosphorylation of the receptor is accompanied by a marked 65% inhibition of the receptor kinase activity. Almost 90% of the decrease in [32P]phosphate content of the receptor after alkaline phosphatase treatment is accounted for by a decrease in phosphotyrosine content in peak 2, while very small decreases are observed in peaks 1 and 3, respectively. These results demonstrate that the extent of phosphorylation of tyrosine residues in receptor domain 2 closely parallels the receptor kinase activity state, suggesting phosphorylation of this domain may play a key role in regulating the insulin receptor tyrosine kinase.
...
PMID:Tyrosine phosphorylation of the insulin receptor beta subunit activates the receptor-associated tyrosine kinase activity. 653 76

The synthesis and phosphorylation of influenza virus nucleoprotein and nonstructural protein were analyzed. The nucleoprotein (NP) was found to be phosphorylated in both infected cells and in isolated virions. The phosphate is in a monoester linkage to a serine residue. Two-dimensional tryptic peptide maps of the 32P-labeled protein, as well as measurements of specific activity, suggests that NP is phosphorylated at one site per molecule. The viral nonstructural (NS 1) protein is also phosphorylated, but on threonine residues. Up to a maximum of two sites per NS 1 molecule could be so modified in infected cells, as demonstrated by two different methods of tryptic peptide analysis and by measurements of the ratio of 32P to 3H-amino-acids incorporated into NS 1 protein species. The NS 1 protein is resolved into four major species of differing isoelectric point in a two-dimensional electrophoretogram. The most acidic species was found to have two phosphorylated sites per molecule, and the next most acidic species contained on the average one phosphate per molecule. Treatment of the phosphorylated species with bacterial alkaline phosphatase demonstrated that the level of phosphorylation is the only identifiable difference between the phosphorylated and unphosphorylated NS 1 species. The distinction between the two unphosphorylated species could not be determined. The distribution of the un-, mono-, and diphosphorylated NS 1 species was characterized at different times after synthesis. These modifications were found to occur very rapidly after translation (30 to 60 s), after transport of the unmodified species from cytoplasm to nucleus of the infected cell. The phosphorylation of NP also takes place rapidly after its synthesis; the site within the cell of the NP phosphorylation has not been unambiguously determined.
...
PMID:The structure and synthesis of influenza virus phosphoproteins. 724 Jan 43

Based on the phosphorylation of the purified actin-fragmin complex, an 80 kDa monomeric kinase (AFK) has been isolated from Physarum polycephalum. Protein chemical analysis and studies involving kinase inhibitors and effectors establish that the AFK is a unique kinase that cannot be classified so far in one of the conventional kinase families. The actin-fragmin kinase behaves as an "independent" kinase since its activity towards the actin-fragmin complex is apparently not regulated by the binding of a ligand (e.g., the cyclic-nucleotides, Ca2+, calmodulin, phosphatidylserine and diolein). Rigorous screening of the substrate specificity suggests that the actin-fragmin complex represents the only substrate for this kinase. This kinase phosphorylates the actin moiety of the actin-fragmin complex at two consecutive threonine residues which constitute one of the contact sites for DNase I (37) and which are also located at one of the proposed actin-actin contact sites along the long-pitch helix of F-actin (38, 39). The physiological importance of this phosphorylation was demonstrated by studying the effect of phosphorylation on the nucleation and the capping activity of the actin-fragmin complex using fluorescence enhancement analysis. As could be demonstrated, the nucleation of actin filaments by the actin-fragmin complex is completely abolished upon phosphorylation by the AFK. Phosphorylation of the complex also interferes with its capping activity, which becomes Ca(2+)-dependent. In addition, capping and nucleating activity is regulated in vitro by phosphoinositides, of which PIP2 displays the highest activity and specificity. PIP2 partially inhibits the nucleation and capping activity of the unphosphorylated actin-fragmin. The capping activity of the phosphorylated actin-fragmin complex was inhibited by PIP2 to a much greater extent as compared to the unphosphorylated actin-fragmin complex. Among all phospholipids tested, PIP2 displayed the highest specificity. Initial experiments with purified preparations of the PP-1, PP-2A, PP-2B, alkaline phosphatase and acid phosphatases showed that PP-1 and PP-2A phosphatases were capable of dephosphorylating the phospho actin-fragmin complex. These findings raised the question of whether these or other protein phosphatases were involved in the dephosphorylation of this substrate in vivo. To address this question, Physarum extracts were subjected to fractionation by ion exchange chromatography, and the column fractions were assayed in a variety of conditions, to identify the protein phosphatases involved in the dephosphorylation of this substrate and to identify the elution position of the major Ser/Thr protein phosphatases present in the Physarum extract.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Microfilament dynamics: regulation of actin polymerization by actin-fragmin kinase and phosphatases. 757 44

The insect stage of the protozoan parasite Leishmania mexicana secretes a phosphomonoesterase in the form of a filamentous complex. The polypeptide subunits of this polymer are modified by phosphoglycans and/or oligomannosyl residues linked to phosphoserine. Based on peptide sequence data of a predominant 100 kDa protein of the filamentous complex, two tandemly arranged, single copy genes, lmsap1 and lmsap2, were cloned and sequenced. lmsap1 predicts a protein with features characteristic of acid phosphatases and a remarkable serine- and threonine-rich region of 32 amino acids close to the C-terminus. In the otherwise identical lmsap2 product, this region is extended to 383 amino acids and is composed of short Ser/Thr-rich repeats. Deletion analysis demonstrates that lmsap1 encodes the major 100 kDa protein of the complex while a minor 200 kDa component is derived from the lmsap2 gene. Null mutants of either gene retain the ability to secrete acid phosphatase filaments, while a deletion of both genes results in Leishmania defective in enzyme formation. The Ser/Thr-rich domains are the targets for phosphoglycan modifications as shown by the expression of secreted fusion proteins composed of these C-terminal regions and the N-terminal domain of a lysosomal acid phosphatase.
...
PMID:Ser/Thr-rich repetitive motifs as targets for phosphoglycan modifications in Leishmania mexicana secreted acid phosphatase. 772 Jun 97

Two cDNAs encode rat intestinal alkaline phosphatases having completely different carboxyl-terminal peptides; one is hydrophobic and fulfills the consensus requirements for glycan phosphatidylinositol linkage, and the other is neither hydrophobic nor hydrophilic, but contains a small amino acid domain (-NSASS-) just distal to a region of 17 threonine residues. Constructs were created using 80% of the amino-terminal portion of one alkaline phosphatase and the carboxyl-terminal portions of each of the isoforms. Both of the carboxyl-terminal peptides supported glycan phosphatidylinositol linkage as demonstrated by the following criteria: 1) plasma membrane targeting in transfected COS-1 cells, 2) release of transfected alkaline phosphatase by phosphatidylinositol-specific phospholipase C, 3) appearance of the trypanosome variable glycoprotein cross-reacting determinant after phospholipase C treatment, 4) ethanolamine incorporation into newly synthesized enzyme, 5) loss of phospholipase C release after mutation of the omega and omega + 2 positions in the putative linkage site, -NSA-, and 6) evidence of surface membrane localization by immunofluorescence using antibody against rat intestinal alkaline phosphatase. These data demonstrate that a predicted hydrophobic carboxyl-terminal sequence is not essential for glycan phosphatidylinositol linkage. Moreover, because both isomers are membrane-bound, the origin of soluble enzyme in the serum is likely to arise from the action of serum phosphatidylinositol-specific phospholipase C.
...
PMID:Two rat intestinal alkaline phosphatase isoforms with different carboxyl-terminal peptides are both membrane-bound by a glycan phosphatidylinositol linkage. 774 44

The mechanism of G protein-mediated inhibition of an inwardly rectifying K+ current (IIR) in adrenal chromaffin cells was investigated using the whole-cell version of the patch clamp technique. In case of recording with use of ATP-containing patch solution, the IIR was well maintained; otherwise, it ran down within 15 min. This run down was not prevented by replacement with adenylyl-imidodiphosphate, a nonhydrolysable analogue of ATP, but was markedly reduced by the addition to the ATP-free solution of 1 microM calyculin A, a specific inhibitor of serine/threonine phosphatase 1 (PP1) and 2A (PP2A). The addition of alkaline phosphatase to the ATP-containing solution facilitated run down of the current, and application of 100 microM H-7, a general kinase inhibitor, reversibly suppressed IIR. These results taken together suggest that inwardly rectifying K+ channels are under the influence of kinase and phosphatase without external signals. Infusion of nonhydrolysable analogues of GTP, guanosine-5'-O-(3-thiophosphate) (GTP gamma S) or guanylyl-imidodiphosphate, through the pipette produced little inward current at -55 mV, but completely inhibited IIR within approximately 5 or 6 min in all cells tested in the presence of 12 microM Mg2+ inside the cell. In contrast, infusion of aluminum fluoride (AlF) complex, another GTP binding (G) protein activator, consistently produced large inward currents, but did not alter IIR noticeably for 15 min in 17% of the cells tested. In the other cells, the inhibition of IIR developed slowly after long latent periods. This inhibitory potency of AlF was not enhanced by an increase in Mg2+ concentrations. Subtraction of the current-voltage relationship before from that noted during the generation of inward current by AlF complex revealed that the inward current diminished progressively with hyperpolarizations, as is the case with a nonselective cation current (INS) induced by a muscarinic agonist. Thus, AlF complex seems to be potent with the generation of INS, but not with IIR inhibition. The addition of 3 microM calyculin A significantly retarded the IIR inhibition by GTP gamma S, whereas that of 1 microM okadaic acid, another inhibitor of PPI and PP2A, markedly prevented the decline of IIR by AIF complex. Our observations suggest that the low potency of AlF complex in inhibiting IIR may be due to interference with phosphatase activity and that the activation of G protein suppresses IIR, probably by enhancing the apparent activity of phosphatase, which may explain run down of the current.
...
PMID:Phosphatase is responsible for run down, and probably G protein-mediated inhibition of inwardly rectifying K+ currents in guinea pig chromaffin cells. 776 18


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---