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)

RNP, Sm and SS-B nuclear antigens from calf thymus were studied with respect to the size distribution on sucrose gradients as well as to the molecular integrity and related structural changes when they were subjected to enzymatic digestions under different conditions. Making a difference with RNP particles, the Sm size distribution is concentration dependent, a property in accordance with the complexity of the Sm particles in comparison with the RNPs. The use of combined effects of temperature, endogenous proteases and RNase A, allowed us to gain insight into the limits of stability of the three antigenic particles. Following treatments in the absence of RNAse A, the degradation products (32-38 Kd molecular weight) of the 70 Kd RNP polypeptide remain stable and associated with other molecules within the RNP particle. It was also found that the phosphate groups of the SS-B protein moiety are only accessible to alkaline phosphatase if the RNA of the SS-B particle is degraded by the action of RNAse A.
...
PMID:RNP, Sm and SS-B antigens from calf thymus: molecular stability upon enzymatic digestion. 209 30

A novel labeling procedure using biotin-conjugated protein-modifying reagents has been employed to study the structure and function of the human erythrocyte hexose transporter. The carbohydrate moiety of the isolated, reconstituted transporter was labeled by using galactose oxidase/biotin hydrazide. Cysteine residues, which are essential for transporter function, were tagged with a biotin-conjugated maleimide. Labeling with this reagent inhibited the binding of cytochalasin B to the transporter. Following sodium dodecyl sulfate-gel electrophoresis, labeling of the transporter and its proteolytic fragments was detected by Western blotting and probing with alkaline phosphatase-conjugated avidin. After tryptic cleavage of the transporter into two membrane domains, preparations reacted with galactose oxidase/biotin hydrazide were labeled on the 25-kDa glycosylated fragment, but not on the carbohydrate-free 19-kDa peptide. Biotin-maleimide-labeled cysteine residues on both peptides. Transporter polypeptide was fragmented more extensively using Staphylococcus aureus V8 protease. Limited digestion produced a broad band of 30-50 kDa and sharper bands of 23 and 21 kDa. More extensive digestion resulted in the disappearance of the 23-kDa peptide and the appearance of sharp bands of 20, 19, 17, 13, 11, 8, and 7 kDa. Biotin label introduced with galactose oxidase/biotin hydrazide was found on the broad 30-kDa band, confirming its identity as a glycopeptide. All of the peptides weighing more than 11 kDa contained cysteine residues labeled with biotin maleimide, while the 8- and 7-kDa peptides were unlabeled. These results demonstrate the potential usefulness of biotin-conjugated reagents as site-specific probes of membrane protein structure.
...
PMID:Biotin-conjugated reagents as site-specific probes of membrane protein structure: application to the study of the human erythrocyte hexose transporter. 212 60

Transforming growth factor (TGF)-beta family is considered to be an important local factor that greatly regulates bone metabolism. However, the effects of this polypeptide on osteoblasts have been divergent under various experimental conditions. Moreover, three forms of TGF-beta have been recently described. Therefore, we reexamined the effects of TGF-beta 1 on clonal murine osteoblastic MC3T3-E1 cells. TGF-beta 1 dose- and time-dependently depressed alkaline phosphatase activity in the cells supported by low concentration of serum. On the contrary, in the same range of concentrations, TGF-beta 1 stimulated DNA synthesis in the cells. These effects of TGF-beta 1 were observed in the cells cultured in the media without or with a high concentration of serum. These effects of TGF-beta 1 are not mediated by endogenous production of prostaglandin, since the basal level of prostaglandin E2 was very low and rather inhibited by TGF-beta 1; and, further, indomethacin did not modify the effects of TGF-beta 1 on the cells under the present conditions. Furthermore, TGF-beta 1 greatly stimulated not only type I but also type III collagen production. Hydroxyurea completely blocked the stimulation of DNA synthesis by TGF-beta 1, but partially inhibited the collagen synthesis, suggesting that the TGF-beta 1-stimulated collagen synthesis is at least in part linked to the proliferation. However, the stimulation of collagen synthesis by TGF-beta 1 was greater than that of DNA synthesis, and further, the amount of hydroxyproline in the cell was evidently augmented by TGF-beta 1. Our data presented here thus suggest that TGF-beta 1 may act on preosteoblasts to increase the number of osteoblasts and the amount of bone organic matrix.
...
PMID:Effects of transforming growth factor-beta 1 on murine clonal osteoblastic cells (MC3T3-E1). 213 92

This study describes the production and characterization of a monoclonal antibody (mAb) against the alkaline phosphatase of Schistosoma mansoni from splenocytes of chronically infected mice. Convenient selection of the mAb was achieved using the catalytic activity of the antigen in a developed enzyme-antigen immunoassay. The mAb was of the IgG1 subclass and it specifically recognized the alkaline phosphatase in adult worm sections by indirect immunofluorescence. Preincubation of the antibody with partially purified adult alkaline phosphatase did not result in inhibition of the enzyme activity and it did not mediate complement-dependent cytotoxicity against mechanically transformed schistosomula in vitro. The mAb was able to immunoprecipitate under reducing conditions a polypeptide of 65 kDa, similar in size to the monomeric subunit of the schistosome enzyme. The specificity of the mAb was assessed by competitive inhibition with antibodies of infected human sera in an immunoadsorption assay. Periodate treatment of the antigen resulted in altered electrophoretic mobility of alkaline phosphatase, which confirmed the presence of carbohydrate in the molecule, but this did not prevent binding by the mAb. Although the use of the mAb in capture assays for detection of circulating alkaline phosphatase in infected host sera was unsuccessful, the production of this antibody confirmed that the enzyme is exposed by adult worms to the host and that it is immunogenic; additionally, a monoclonal probe is available for further characterization of the structure and function of this important parasite surface molecule.
...
PMID:Production of a mouse monoclonal antibody against the alkaline phosphatase of adult Schistosoma mansoni. 216 96

Cold-sensitive mutations in the secD locus of Escherichia coli result in severe defects in protein export at the non-permissive temperature of 23 degrees C. DNA sequence of a cloned fragment that includes the secD locus reveals open reading frames for seven polypeptide chains. Both deletions and TnphoA insertions in this clone have been used in maxicell and complementation studies to define the secD locus and its products. The secD mutations fall into two complementation groups, defining genes we have named secD and secF. These two genes comprise an operon, the first case of two genes involved in the export process being co-transcribed. The DNA sequence of the two genes along with alkaline phosphatase fusion analysis indicates that they code for integral proteins of the cytoplasmic membrane. We suggest that these two proteins may form a complex in the membrane which acts at late steps in the export process.
...
PMID:The secD locus of E.coli codes for two membrane proteins required for protein export. 224 73

Purified carbohydrate-binding protein 35 (CBP35) and extracts of mouse cells containing CBP35 were analyzed by two-dimensional gel electrophoresis. Such an analysis on recombinant CBP35, obtained by expression of a cDNA clone in Escherichia coli, yielded a pI value of 8.7. When extracts of mouse 3T3 cells were subjected to two-dimensional gel electrophoresis and immunoblotting, two spots were observed, corresponding to pI values of 8.7 and 8.2. The pI 8.2 species represents post-translational modification of the CBP35 polypeptide (pI 8.7) by the addition of a single phosphate group. This conclusion is based on the finding that purified CBP35 contained a pI 8.2 species that was labeled with 32PO4 and could be converted to the unlabeled pI 8.7 species by alkaline phosphatase treatment. The phosphorylated (pI 8.2) form of CBP35 is found in both the cytosolic and nuclear fractions, whereas the unphosphorylated (pI 8.7) species is found exclusively in the nuclei. Quiescent populations of 3T3 fibroblasts (confluent monolayers or serum-starved sparse cultures) are characterized by the predominance of phosphorylated CBP35. Stimulation of the same cells into the proliferative state resulted in an increase in the amount of the phosphorylated species; more dramatic, however, is the elevation of the level of the unphosphorylated form, which is barely detectable in quiescent cells.
...
PMID:Carbohydrate-binding protein 35. Isoelectric points of the polypeptide and a phosphorylated derivative. 217 Mar 92

1. Liver plasma membranes originating from the sinusoidal, lateral and canalicular surface domains of hepatocytes were covalently labelled with sulpho-N-hydroxysuccinamide-biotin. After solubilization in Triton X-114, treatment with a phosphatidylinositol-specific phospholipase C (PI-PLC), two-phase partitioning and 125I-streptavidin labelling of the proteins resolved by PAGE, six major polypeptides (molecular masses 110, 85, 70, 55, 38 and 35 kDa) were shown to be anchored in bile canalicular membrane vesicles by a glycosyl-phosphatidylinositol (G-PI) 'tail'. 2. Permeabilized 'early' and 'late' endocytic vesicles isolated from liver were also examined. Two polypeptides (110 and 35 kDa) were shown to be anchored by a G-PI tail in 'late' endocytic vesicles. 3. Analysis of marker enzymes in bile-canalicular vesicles treated with PI-PLC showed that 5'-nucleotidase and alkaline phosphatase, but not leucine aminopeptidase and ecto-Ca2(+)-ATPase activities were released from the membrane. A low release and recovery of alkaline phosphodiesterase activity was noted. The cleavage from the membrane of 5'-nucleotidase as a 70 kDa polypeptide was confirmed by Western blotting using an antibody to this enzyme. 4. Antibodies raised to proteins released from bile-canalicular vesicles by PI-PLC treatment, and purified by partitioning in aqueous and Triton X-114 phases, localized to the bile canaliculi in thin liver sections. Antibodies to proteins not hydrolysed by this treatment stained by immunofluorescence the sinusoidal and canalicular surface regions of hepatocytes. 5. Antibodies generated to proteins cleaved by PI-PLC treatment of canalicular vesicles were shown to identify, by Western blotting, a major 110 kDa polypeptide in these vesicles. Two polypeptides (55 and 38 kDa) were detected in MDCK and HepG-2 cultured cells. 6. Since two of the six G-PI-anchored proteins targeted to the bile-canalicular plasma membrane were also detected in 'late' endocytic vesicles, the results suggest that a junction where exocytic and endocytic traffic routes meet occurs in a 'late' endocytic compartment.
...
PMID:Priority targeting of glycosyl-phosphatidylinositol-anchored proteins to the bile-canalicular (apical) plasma membrane of hepatocytes. Involvement of 'late' endosomes. 217 97

The aim of our work was to assess the performance of tissue polypeptide antigen in detecting hepatocellular carcinoma in cirrhotic patients, while also checking for any influence of liver dysfunction on the serum level of the marker. One hundred and twenty-five consecutive cirrhotic patients, 35 with and 90 without, hepatocellular carcinoma were studied. Tissue polypeptide antigen had a different distribution in the two groups and the best diagnostic accuracy with 48.6% sensitivity and 85.6% specificity was found at the cut-off value of 240 UL-1. In cirrhotic patients significant linear correlations were found between tissue polypeptide antigen and alanine-transaminase, aspartate-transaminase, G-glutamyl-transpeptidase and alkaline phosphatase; there was no correlation with bilirubin or pseudo-cholinesterase. In patients with hepatocellular carcinoma a significant linear correlation was found only with alanine and aspartate transaminase and G-glutamyl-transpeptidase. The analysis of covariance still showed a significant difference between mean tissue polypeptide antigen levels in the two groups also accounting for covariates. These results suggest that: a) the liver dysfunction may be involved in increasing tissue polypeptide antigen values; b) tissue polypeptide antigen has a different distribution in cirrhotic patients with and without hepatocellular carcinoma also accounting for covariates; these findings further support the specificity of tissue polypeptide antigen.
...
PMID:The serum tissue polypeptide antigen in the detection of hepatocellular carcinoma in cirrhotic patients. 217 22

The determined nucleotide sequence of the Klebsiella pneumoniae UNF5023 gene pulA comprises a single open reading frame coding for a 1090-residue precursor of the secreted protein pullulanase. The predicted sequence of this protein is highly homologous to that of pullulanase of Klebsiella aerogenes strain W70. However, the UNF5023 pullulanase lacks a collagen-like sequence present at the N-terminus of the mature W70 enzyme and differs further from the W70 pullulanase around residue 300 and at the C-terminus. Pullulanases with or without the collagen-like sequence could not be separated by gel electrophoresis under denaturing or non-denaturing conditions, and were unaffected by collagenase. A large central domain which is highly conserved in both UNF5023 and W70 polypeptides contains eight short sequences that are also found in amylases and iso-amylases. Linker mutations in the region of the UNF5023 pulA gene coding for this domain abolished catalytic activity without affecting transport of the polypeptide across the outer membrane. Hybrid proteins comprising at least the amino-terminal 656 residues of prepullulanase fused to alkaline phosphatase were partially localized to the cell surface, as judged by their accessibility to anti-pullulanase serum in immuno-fluorescence tests. On the basis of these results, we tentatively propose that secretion signals required for recognition and translocation across the outer membrane via the pullulanase-specific extension of the secretion pathway are located near the N-terminus of the pullulanase polypeptide.
...
PMID:Molecular characterization of pulA and its product, pullulanase, a secreted enzyme of Klebsiella pneumoniae UNF5023. 218 Dec 42

The development of bone metastases in cancer can be monitored easily using three markers: 24 h urinary hydroxyproline excretion (HOP) (an index of osteoclastic activity), serum alkaline phosphatase (Alk.Ph.) (an index of osteoblastic activity) and 24 h whole body retention of 99mTc-methylene diphosphonate (WBR%) (an index of bone turnover). To evaluate the effectiveness of this group of bone tumor markers in breast cancer we compared it with the following group of three markers which are commonly used in the monitoring of breast cancer and in the follow-up of advanced disease with or without bone metastases: carcinoembryonic antigen (CEA), tissue polypeptide antigen (TPA) and breast carcinoma antigen (CA 15/3). In 48 patients with bone metastases CEA, TPA and CA 15/3 were shown to be sensitive (79%, 85%, 90% respectively), while HOP, Alk.Ph. and WBR%, which are commonly accepted as reliable markers of bone activity, showed a lower sensitivity (67%, 46%, 75% respectively). These results may be explained by the lack of osteoclastic or osteoblastic (or both) activity at the time of diagnosis. This explanation is supported by the fact that the bone markers HOP, Alk.Ph. and WBR% were found to be more sensitive than the others in the subsequent follow-up study. We conclude that in our study, CEA, TPA and CA 15/3 are at first more sensitive than Alk.Ph., HOP and WBR% but during the follow-up Alk.Ph., HOP and WBR% are possibly both more specific and more sensitive.
...
PMID:Comparison between CEA, TPA, CA 15/3 and hydroxyproline, alkaline phosphatase, whole body retention of 99mTc MDP in the follow-up of bone metastases in breast cancer. 228 79


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

---