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)

1. To identify the functional groups that are involved in the conversion of beta-glycerophosphate by alkaline phosphatase (EC 3.1.3.1) from pig kidney, the kinetics of alkaline phosphatase were investigated in the pH range 6.6-10.3 at substrate concentrations of 3 muM-30 mM. From the plots of log VH+ against pH and log VH+/KH+m against pH one functional group with pK = 7.0 and two functional groups with pK = 9.1 were identified. These groups are involved in substrate binding. Another group with pK = 8.8 was found, which in its unprotonated form catalyses substrate conversion. 2. GSH inhibits the alkaline phosphatase reversibly and non-competitively by attacking the bound Zn(II). 3. The influence of the H+ concentration on the activation by Mg2+ ions of alkaline pig kidney phosphate was investigated between pH 8.4 and 10.0. The binding of substrate and activating Mg2+ ions occurs independently at all pH values between 8.4 and 10.0. The activation mechanism is not affected by the H+ concentration. The Mg2+ ions are bound by a functional group with a pK of 10.15. 4. A scheme is proposed for the reaction between enzyme, substrate, Mg2+ and H+ and the overall rate equation is derived. 5. The mechanism of substrate binding and splitting by the functional groups of the active centre is discussed on the basis of a model. Mg2+ seems to play a role as an autosteric effector.
Biochem J 1975 Sep
PMID:The mechanism of hydrolysis of beta-glycerophosphate by kidney alkaline phosphatase. 0 Sep 95

The diagnostic specificity of a new method to detect obstructive jaundice by determination of lipoprotein X (LP-X) was tested in 144 patients with different kinds of hepatic diseases and compared with the usual chemical "obstructive jaundice specific" tests, such as bilirubin, SGOT, SGPT, alkaline phosphatase, LAP and gamma-GT. The LP-X test was performed by using all-in test kit LP-X Rapidophor" low-voltage electrophoresis of Immuno AG/Wien. The results were correlated with the histological classification of the liver biopsy specimen. In 82% of the histologically verified cases of obstructive jaundice the result of the LP-X test was positive, whilst in 98.5% of the histologically negative cases the result of the LP-X test was negative. Hence, this LP-X method proved superior to chemical methods in providing a clear-cut positive or negative answer to the presence of cholestasis. Furthermore, the LP-X test was suitable for long-term follow-up investigation of patients with obstructive jaundice.
Wien Klin Wochenschr 1975 Sep 05
PMID:[The diagnosis of cholestasis: lipoprotein X (LP-X) (author's transl)]. 0 12

A stable deoxyribonucleic acid (DNA) polymerase (EC 2.7.7.7) with a temperature optimum of 80 degrees C has been purified from the extreme thermophile Thermus aquaticus. The enzyme is free from phosphomonoesterase, phosphodiesterase and single-stranded exonuclease activities. Maximal activity of the enzyme requires all four deoxyribonucleotides and activated calf thymus DNA. An absolute requirement for divalent cation cofactor was satisfied by Mg2+ or to a lesser extent by Mn2+. Monovalent cations at concentrations as high as 0.1 M did not show a significant inhibitory effect. The pH optimum was 8.0 in tris(hydroxymethyl)aminomethane-hydrochloride buffer. The molecular weight of the enzyme was estimated by sucrose gradient centrifugation and gel filtrations on Sephadex G-100 to be approximately 63,000 to 68,000. The elevated temperature requirement, small size, and lack of nuclease activity distinguish this polymerase from the DNA polymerase of Escherichia coli.
J Bacteriol 1976 Sep
PMID:Deoxyribonucleic acid polymerase from the extreme thermophile Thermus aquaticus. 0 32

Nicotinamide adenine dinucleotide phosphate phosphomonoesterase was isolated and partially purified from wheat (Triticum aestivum L. var. Selkirk) leaves. The enzyme had KNADP value of 1.4 X 10(-4) M and a pH optimum of 5.9. In vitro activity of this enzyme was unaffected by precursors of NAD (nicotinamide and nicotinic acid) or cytokinins (kinetin and benzimidazole). However, when detached wheat leaves were treated with solutions of these compounds, the precursors lowered the specific activity while the cytokinins enhanced the activity. It is suggested that spatial separation and compartmentation of the enzyme and its substrate NADP account for the similar effect of benzimidazole on both.
Experientia 1976 Sep 15
PMID:Effect of benzimidazole on nicotinamide adenine dinucleotide phosphate phosphomonoesterase activity in wheat leaves. 0 13

In active odontoblasts from the rat incisor, used as a model system for biologic calcification, two distinguishable enzyme activities capable of degrading adenosine monophosphate (ATP) exist. Once can be inhibited ny 1-tetramisole, (+/-)-2,3,5,6,-tetrahydro-6-phenylimidazo (2.1B) THIAZOLE HYDROCHLORIDE (Levamisol) and (+/-)-6(m-bromophenyl)-5.6-dehydroimidazo (2.1-b) thiazole oxalate (R823) and is probably identical with nonspecific alkaline phosphatase (EC 3.1.3.1). The activity of the other enzyme, named Ca2+-ATPase, is dependent on the presence of Ca2+ or Mg2+ and is activated by these ions. The pH optimum of Ca2+-ATPase is 9.8. The Ca2+-ATPase is unaffected by Levamisole, R 8231, ouabain, ruthenium red, Na+ and K+ ions. Maximal activity was found against ATP, whereas adenosine diphosphate, guanosine triphosphate, inosine triphosphate and adensoine monophosphate were hydrolysed at lower rate. It may be speculated that the Ca2+-ATPase is concerned with the transmembranous transport of Ca2+ ions to the mineralization front.
J Histochem Cytochem 1976 Sep
PMID:A comparison of ATP-degrading enzyme activities in rat incisor odontoblasts. 0 54

Inorder to gain a foothold in clarifying the functional significance of fatstoring cells, an enzyme histochemical study on these cells was carried out. Fat-storing cells showed no alkaline phosphatase, acid phosphatase or esterase activity but demonstrated a marked gamma-glutamyl transpeptidase activity suggesting the possibility of its participation in the synthesis of fiber protein. This possibility was further heightened by its remarkable activity noted at the site of progressive fibrosis. Fat-storing cells under a normal condition partake in the formation of fibers supporting the sinusoidal wall, and under an abnormal condition gradually change their shape with loss of fat droplets and then transform into fibroblast-like cells closely related to the progress of fibrosis.
Acta Pathol Jpn 1976 Sep
PMID:Enzyme histochemical study on fat-storing cells (so-called Ito's cell) of liver. 1 35

The absorbance of an alkaline solution of 4-nitrophenyl phosphate is a function of temperature. Quantitative evaluation of this phenomenon indicates that it (a) depends on the concentration of the compound and is independent of source, buffer concentration, and pH above 9.0; (b) is reversible; (c) is not a result of alkaline hydrolysis or 4-nitrophenol contamination; and (d) correlates with a temperature-induced shift of its absorbance spectrum. The phenomenon may represent a potential analytical problem in methods for alkaline phosphatase in which this compound is the substrate. If thermal equilibrium is not reached and maintained during an alkaline phosphatase assay, the thermochromic response will be included in the measured rate. The magnitude of this error depends on the thermal response and control characteristics of each particular instrument and the reaction conditions under which such an analysis is performed.
Clin Chem 1977 Sep
PMID:Temperature dependence of the absorbance of alkaline solutions of 4-nitrophenyl phosphate--a potential source of error in the measurement of alkaline phosphatase activity. 1 64

Activities of the enzymes glutamine synthetase (EC 6.3.1.2.), glucosamine 6-phosphate acetyltransferase (EC 2.3.1.4.), uridine 5'-diphosphate (UDP)-N-acetylglucosamine pyrophosphorylase (EC 2.7.23.), UDP-N-acetylglucosamine 4-epimerase (EC 5.1.3.7.), fructose 1,6-diphosphate phosphatase (EC 3.13.11.), L-glutamine-fructose 6-phosphate transamidase (EC 5.3.1.19.), alkaline phosphatase (EC 3.1.3.1.), and malic dehydrogenase (EC 1.1.1.37) were assayed in partially purified extracts prepared at different stages of myxospore formation and germination in liquid cultures of Myxococcus xanthus. The specific activities of the first six of these enzymes increased 4.5- to 7.5-fold after 2 h of induction with 0.5 M glycerol or 0.2 M dimethyl sulfoxide. The increase in specific activities of these six enzymes was not observed in a mutant unable to be induced with glycerol. During the first 2 to 4 h of induction and during the first hour of germination, the level of these enzymes decreased to the level characteristic of vegetative cells. It is suggested that the six enzymes are responsible for the increased conversion of fructose 1,6-diphosphate to UDP-N-acetylgalactosamine, the major precursor of the myxospore coat.
J Bacteriol 1977 Sep
PMID:Myxospore coat synthesis in Myxococcus xanthus: enzymes associated with uridine 5'-diphosphate-N-acetylgalactosamine formation during myxospore development. 1 17

The CentrifiChem centrifugal microanalyser (model 300) has been used routinely in this laboratory for two years. Its reliability for performing total bilirubin, aspartate aminotransferase alkaline phosphatase and gamma-glutamyl transferase analyses during this time is reported, using methods modified in a preliminary study. Accuracy of the analyses has been assessed by comparing the results with those from other analytical systems and by using commercial control sera. Determinations have been made for within-batch, between-day (20 days), and long term (100 weeks) precision. Other aspects evaluated were the range over which methods were linear and the cost of operation.
Ann Clin Biochem 1977 Sep
PMID:A long-term evaluation of the CentrifiChem centrifugal microanalyser during routine use in the clinical biochemistry laboratory. 2 7

The activities of gamma-glutamyl transpeptidase (gamma-GTP), alkaline phosphatase (A-p), and leucine aminopeptidase (LAP) were examined in 18 cases of hepatomas. The activity of gamma-GTP was most remarkable in the hepatoma consisting of small to medium-sized tumor cells showing the least atypism. The enzyme activity found in the type composed of large tumor cells resembled that of normal liver and was considered to be the most mature form of the neoplasm. This enzyme was not found in the immature type composed of small typical tumor cells. A-P activity was seen in only a few cases of hepatoma; conspicuous in one case showing immature features and sporadically in one case with florid histological pattern. The activity of this enzyme could not be confirmed in the type demonstrating marked gamma-GTP activity. LAP activity was noted in the majority of cases, especially marked in the medium-sized tumor cells, but there was hardly any connection between this enzyme and histological type. In general, the cases demonstrating positive gamma-GTP activity tended to show LAP activity. Although the activity of gamma-GTP and that of A-p usually showed an inverse relation, all three enzymes demonstrated almost equal activity in the type showing a florid histological pattern.
Acta Pathol Jpn 1977 Sep
PMID:Enzyme histochemical study on hepatoma--the relation between enzyme activity and histological type. 2 15


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