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)

We present a simple, efficient and rapid method for affinity-purifying antibodies from a relatively crude antiserum in quantities large enough to screen a DNA expression library. The method presents a very convenient way to remove crossreacting or contaminating antibody specificities. The affinity matrix, antigen non-covalently bound to nitrocellulose, is prepared by the electrophoretic separation of antigen by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, followed by the transfer of antigen to nitrocellulose. The matrix can be used repeatedly. A brief wash with 6 M guanidine hydrochloride is included between steps to remove residual antibodies which bind with high affinity to nitrocellulose-bound antigen. Various buffer solutions were assessed as antibody/antigen-dissociating agents. Glycine/HCl buffer, pH 2.5, appeared to be the most efficient in our hands, although a number of other less efficient dissociating reagents, including 4.5 M magnesium chloride, pH 7.5, 6 M urea, pH 7, and 0.05 M diethylamine, pH 11.5, also could be used; these may be the elution conditions of choice for other antibody/antigen combinations. The use of affinity-purified antibody solutions instead of the corresponding antisera gave increased signal-to-noise ratios with the detection systems that are commonly used to identify positive signals in screening expression libraries. Protein A- and goat anti-rabbit-alkaline phosphatase conjugates gave the most sensitive signals.
...
PMID:Nitrocellulose-bound antigen repeatedly used for the affinity purification of specific polyclonal antibodies for screening DNA expression libraries. 312 68

Analogues of bromo-levamisole and guanidine derivatives including cimetidine are examined in vitro in order to investigate their comparative inhibition, towards alkaline phosphatase (ALP) from human liver and diamine-oxidase (DAO) from human placenta. Bromo-levamisole, considered as a potent selective uncompetitive inhibitor of ALP (Ki, 2.8.10(-6) M at pH 10.5) is shown to be a noncompetitive inhibitor of DAO (Ki = 7.10(-4) M). According to the structure-inhibition relationship, the imidazole ring is important for ALP and DAO inhibition. The phenyl ring of bromo-levamisole is required for ALP inhibition but not for DAO inhibition, which is mediated mainly by aminoguanidine or guanidine groups. These results have allowed the selection of cimetidine, an H2-antagonist but also an immunomodulating compound, as inhibitor of these two enzymes. Cimetidine is an uncompetitive inhibitor of ALP (Ki = 3.2.10(-3) M at pH 10.5), and a good inhibitor of DAO (I50 = 3.8.10(-4) M). The Ki of ALP is commonly calculated at pH 10.5, but to study the role of the enzyme at the physiological pH, the inhibition has also been performed at pH 7.4. The Ki values are only slightly affected by this pH variation. So far several compounds, including levamisole, imidazole, theophylline and aminoguanidine are known to possess immunomodulating activities in vivo and/or in vitro and inhibit ALP and/or DAO. Therefore, it seems reasonable to assume that the inhibition of enzymes is involved in the immunomodulating effects of these drugs, when the ranges of active concentrations are similar for these properties.
...
PMID:Comparative inhibition of human alkaline phosphatase and diamine oxidase by bromo-levamisole, cimetidine and various derivatives. 314 66

Rat bone marrow cells were intraperitoneally implanted within a diffusion chamber with a decalcified bone matrix or a 4 M guanidine hydrochloride extracted matrix (G-res) as control. The chamber was harvested after 28 days and soft X-ray photography, histological examination, determination of alkaline phosphatase activity and calcium content were performed. With the decalcified bone matrix, cartilage and bone formation was observed and both alkaline phosphatase activity and calcium content were significantly higher than those in control chambers. Each chromatographic fraction on Sephacryl S-200 of the 4 M guanidine hydrochloride extract (G-ext) from the decalcified bone matrix was reconstituted with G-res and implanted either subcutaneously or intraperitoneally within a diffusion chamber with marrow cells. Intrachamber or subcutaneous cartilage and bone formation was detected by only one chromatographic fraction. When marrow-derived fibroblast-like cells were implanted intraperitoneally within a diffusion chamber with a decalcified bone matrix, cartilage and bone formation was detected, which was not the case with G-res. These results suggest that a certain factor, probably bone morphogenetic protein, which induces ectopic bone formation, allows marrow cells to differentiate into bone and cartilage tissues and there may exist so-called "inducible osteoprogenitor cells" in the marrow-derived fibroblast-like cell preparation.
...
PMID:Chondrogenesis and osteogenesis of bone marrow-derived cells by bone-inductive factor. 316 33

Timegadine is a tri-substituted guanidine derivative which inhibits both arachidonate cyclo-oxygenase and lipoxygenase activity. In a 24-week randomized double-blind controlled trial, timegadine 500 mg/day was compared with naproxen 750 mg/day in two groups of 20 patients with active rheumatoid arthritis. In the timegadine group, significant improvements were seen in both biochemical and clinical markers of disease activity, i.e. ESR, serum IgG and IgM, leukocyte and platelet counts, duration of morning stiffness, Ritchie index, number of swollen joints, pain, and general condition. In the naproxen group, only the Ritchie index improved. Differences between treatments, when present, were always in favour of timegadine. Serum alkaline phosphatase rose during the first 8 weeks of treatment in the timegadine group. A transient rise was also seen in the naproxen group. The side effects reported were mainly gastrointestinal and allergic, the latter being more frequently found in the timegadine group. Timegadine is superior to naproxen in controlling disease activity in rheumatoid arthritis, and appears to possess disease-modifying properties.
...
PMID:Timegadine: more than a non-steroidal for the treatment of rheumatoid arthritis. A controlled, double-blind study. 329 Oct 99

1. Solubilized and membrane-bound alkaline phosphatase showed Michaelis-Menten behavior in a wide range of different substrate concentrations. 2. Membrane-bound alkaline phosphatase has a molecular weight of 130,000 and its minimum active configuration comprises two identical subunits of about 65,000. 3. The two forms of the enzyme behave similarly with respect to NaCl, urea and guanidine HCl. 4. Catalytic groups have pK values of about 8.5 and 9.7 for both membrane-bound and solubilized enzyme.
...
PMID:Triton X-100 solubilized bone matrix-induced alkaline phosphatase. 366 37

Exhaustive in vitro dephosphorylation of porcine neurofilaments (NFs) by alkaline or acid phosphatase did not cause a dissociation of the 210-kD (NF-H), 160-kD (NF-M), or 70-kD (NF-L) subunits and had no effect on the reassembly of NFs from urea or guanidine solution. Electron microscopy revealed that the NFs reassembled from isolated or dephosphorylated subunits had similar morphologies. Phosphatase treatment caused significant increases in the mobilities of NF-M and NF-H on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, suggesting that the subunits underwent marked conformational changes after dephosphorylation. Chemical phosphate analysis showed that as isolated NF-H, NF-M, and NF-L contained about 22, 11, and 3 mol phosphate/mol polypeptide, respectively. The corresponding values for the three subunits from alkaline phosphatase-treated NFs were about 8, 6, and 2 mol phosphate/mol polypeptide, respectively. These results indicate the occurrence of a class of phosphate moieties that is not accessible to exogenous phosphatases.
...
PMID:Dephosphorylation of neurofilaments by exogenous phosphatases has no effect on reassembly of subunits. 373 90

The potential use of the protein denaturant guanidine hydrochloride to inhibit selectively the enzyme activity of serum alkaline phosphatase isoenzymes from liver, bone, intestine, and placenta was investigated. Inhibition of each isoenzyme was shown to be dependent on time and concentration of inhibitor. In the presence of 0.3 mol/l (28.7 g/l) guanidine hydrochloride for 170 seconds 14%, 47%, and 90% of the total alkaline phosphatase activity remained in samples of bone, liver, and intestinal origins, respectively. In contrast, the activity of the placental isoenzyme increased by 24%. The degree of inhibition was shown to be independent of total alkaline phosphatase activity. Investigations were performed at 37 degrees C using the Cobas Bio centrifugal analyser. We conclude that this reagent has several practical advantages over urea as a selective inhibitor of alkaline phosphatase isoenzymes, including a faster and more reproducible inhibition at a much lower reagent concentration.
...
PMID:Quantitative method for determining serum alkaline phosphatase isoenzyme activity I. Guanidine hydrochloride: new reagent for selectively inhibiting major serum isoenzymes of alkaline phosphatase. 376 Feb 33

A method for quantitating the liver, bone, intestinal and placental alkaline phosphatase activity of serum, using an algorithm for converting selective inactivation by guanidine hydrochloride, L-phenylalanine, and heat into equivalent isoenzyme activity is described. The method can individually quantify mixtures of isoenzymes to within a margin of 3%; it has acceptable reproducibility and has been used to develop both age and sex related reference ranges. Analysis time is about 30 minutes. The clinical reliability of this method has been shown in a study of 101 patients, in 79% of whom isoenzyme results were compatible with the final clinical diagnosis; in 10% a clinical diagnosis resulted from isoenzyme analysis, and in a further 11% the source of the increased alkaline phosphatase activity was identified and supported by electrophoresis, with a definite clinical diagnosis yet to be made.
...
PMID:Quantitative method for determining serum alkaline phosphatase isoenzyme activity II. Development and clinical application of method for measuring four serum alkaline phosphatase isoenzymes. 376 Feb 34

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.
...
PMID:Analysis of Halobacterium halobium gas vesicles. 473 10

1. The purification of the ;vegetative' alkaline phosphatase of Bacillus subtilis 168 was simplified by ionic elution of the enzyme from intact cells. 2. The enzyme has a molecular weight of about 70000 and treatment of the enzyme with 10mm-hydrochloric acid or 6.0m-guanidine hydrochloride, beta-mercaptoethanol (0.1m) gives rise to enzymically inactive subunits. 3. The amino acid composition of the enzyme was determined. The N-terminal residue determined by the DNS chloride method is glycine. 4. The properties of this enzyme were compared with the ;sporulation' alkaline phosphatase of the same strain. 5. Although the ;sporulation' enzyme differs from the ;vegetative' enzyme in its physiology of appearance and apparent mRNA stability, an examination of properties of the enzymes revealed no differences. 6. The enzyme from both cell forms is bound to the particulate fraction of cell extracts, but can be solubilized by high concentrations of magnesium chloride; removal of the magnesium chloride, by dialysis, results in precipitation of both enzymes. Both enzymes can be removed from intact cells by ionic elution. 7. The ;vegetative' and ;sporulation' enzymes have identical pH optima, K(m) and K(i) values and electrophoretic mobilities in cellulose acetate. 8. Their half-life is 28min at 65 degrees C and their Q(10) is 1.25. 9. The molecular size determined by gel filtration on Sephadex G-100 is about 69000. 10. ;Vegetative' and ;sporulation' forms gave precipitin lines that were continuous and non-spurred when tested against antiserum prepared against the ;vegetative' enzyme. 11. The ;sporulation' alkaline phosphatase appears to be associated with stage II of sporulation and appears to be induced by something specifically concerned in sporulation and not by phosphate starvation.
...
PMID:Sporulation in Bacillus subtilis 168. Comparison of alkaline phosphatase from sporulating and vegetative cells. 500 77


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

---