Alkaline phosphatase isoenzymes.

1982 ◽  
Vol 28 (10) ◽  
pp. 2007-2016 ◽  
Author(s):  
D W Moss
Keyword(s):  
Alkaline Phosphatase ◽  
Quantitative Analysis ◽  
Posttranslational Modifications ◽  
Quantitative Methods ◽  
Molecular Forms ◽  
Future Research ◽  
Alkaline Phosphatases ◽  
Isoenzyme Analysis ◽  
Alkaline Phosphatase Isoenzymes ◽  
Alkaline Phosphatase Isoenzyme

Abstract The human alkaline phosphatases constitute a system of multiple molecular forms of enzymes in which heterogeneity is partly due to genetic factors and partly to posttranslational modifications. Recognition of the nature and occurrence of these multiple forms has made a significant contribution both to the understanding of changes in alkaline phosphatase values for serum in disease and to the use of alkaline phosphatase measurements in diagnosis. Many of the diagnostic advantages of alkaline phosphatase isoenzyme analysis can be obtained with the aid of qualitative methods such as zone electrophoresis. However, quantitative methods are needed to take full advantage of the potential benefits of isoenzyme analysis. Selective inactivation methods can be applied successfully to the quantitative analysis of bone and liver alkaline phosphatases in serum. However, the aim of future research should be to remove the limitations at present imposed on quantitative analysis by the close similarities of bone and liver alkaline phosphatases.

Alkaline phosphatase. I. Kinetics and inhibition by levamisole of purified isoenzymes from humans.

1976 ◽  
Vol 22 (7) ◽  
pp. 972-976 ◽  
Author(s):  
H Van Belle
Keyword(s):  
Alkaline Phosphatase ◽  
Substrate Concentration ◽  
Human Liver ◽  
Alkaline Phosphatases ◽  
Mechanism Of Inhibition ◽  
Optimum Ph ◽  
Alkaline Phosphatase Isoenzymes

Abstract I studied the kinetics and sensitivity toward inhibition by levamisole and R 8231 of the most important human alkaline phosphatase isoenzymes. N-Ethylaminoethanol proved superior to the now widely used diethanolamine buffer, especially for the enzymes from the intestine and placenta, behaving as an uncompetitive activator. The optimum pH largely depends on the substrate concentration. The addition of Mg2+ has no effect on the activities. The meaning of Km-values for alkaline phosphatases is questioned. Isoenzymes from human liver, bone, kidney, and spleen are strongly inhibited by levamisole or R 8231 at concentrations that barely affect the enzymes from intestine or placenta. The inhibition is stereospecific, uncompetitive, and not changed by Mg2+. Inhibition is counteracted by increasing concentrations of N-ethylaminoethanol. The mechanism of inhibition is suggested to be formation of a complex with the phosphoenzyme.

Quantitative alkaline phosphatase isoenzyme determination by electrophoresis on cellulose acetate membranes.

1977 ◽  
Vol 23 (1) ◽  
pp. 28-34 ◽  
Author(s):  
W H Siede ◽  
U B Seiffert
Keyword(s):  
Alkaline Phosphatase ◽  
Cellulose Acetate ◽  
Clinical Laboratory ◽  
Kinetic Assay ◽  
Specific Staining ◽  
Cellulose Acetate Membranes ◽  
Alkaline Phosphatase Isoenzymes ◽  
Elution Method ◽  
Routine Clinical Laboratory ◽  
Alkaline Phosphatase Isoenzyme

Abstract We present a new method for quantitative determination of alkaline phosphatase isoenzymes. This method consists of electrophoretic separation on cellulose acetate membranes, special fixation technique to avoid elution and diffusion of enzyme protein during incubation, specific staining, and quantitative evaluation by densitometric measurement. We highly recommend the precedure for routine clinical laboratory use. In all normal individuals we observe two isoenzymes of hepatic origin and one isoenzyme each of osseous, intestinal, and biliary origin. Quantitative normal values are presented. Precision of the method is calculated, the CV being less than 10%. The exactness of densitometric quantification is proved by comparison with kinetic assay of alkaline phosphatase isoenzymes by use of an elution method. Clinical implications of alkaline phosphatase isoenzymograms are reported and discussed in detail.

scholarly journals Reaction Rate Retardation as a Method for Serum Alkaline Phosphatase Isoenzyme Measurement

1980 ◽  
Vol 17 (4) ◽  
pp. 192-198 ◽  
Author(s):  
Pamela B Brown ◽  
K O Lewis
Keyword(s):  
Alkaline Phosphatase ◽  
Reaction Rate ◽  
Serum Alkaline Phosphatase ◽  
Enzyme Reaction ◽  
Intestinal Alkaline Phosphatase ◽  
Wide Range ◽  
Alkaline Phosphatase Isoenzymes ◽  
Sensitivity And Selectivity ◽  
Rate Retardation ◽  
Alkaline Phosphatase Isoenzyme

A method for serum alkaline phosphatase isoenzymes using an enzyme reaction rate analyser is described. The complete urea-induced degradation of enzyme activity is monitored, from which individual isoenzyme activities are obtained by calculating the constituent exponential components of the degradation curve. Activities have been measured with adequate sensitivity and selectivity for up to four isoenzyme components in normal and in pathological sera. The identity of each isoenzyme present is assigned from its characteristic degradation half-life, and by this method bone and liver alkaline phosphatase are clearly distinguished and quantitated, and a composite value for placental-intestinal alkaline phosphatase activity is obtained. The approach promises to be applicable to a wide range of isoenzymes, and in analogy with ‘reaction rate’ the term ‘reaction rate retardation’ is suggested for the procedure.

A fetal intestinal-type alkaline phosphatase in hepatocellular carcinoma tissue.

1977 ◽  
Vol 23 (9) ◽  
pp. 1615-1623 ◽  
Author(s):  
K Higashino ◽  
R Otani ◽  
S Kudo ◽  
Y Yamamura
Keyword(s):  
Alkaline Phosphatase ◽  
Electrophoretic Mobility ◽  
Normal Liver ◽  
Heat Stability ◽  
Intestinal Type ◽  
Intestinal Alkaline Phosphatase ◽  
Alkaline Phosphatases ◽  
Adult Type ◽  
Alkaline Phosphatase Isoenzyme ◽  
Hepatocellular Carcinoma Tissue

Abstract We examined 19 hepatoma tissues for alkaline phosphatase isoenzyme and found that six have both the Kasahara isoenzyme and an alkaline phosphatase with a unique electrophoretic mobility, in addition to the liver-type enzyme. From two of six carcinoma tissues, the abnormal enzyme was partly purified and subjected to a detailed analysis, which clarified that the abnormal enzyme resembled a fetal intestinal alkaline phosphatase in most of its enzymic and immunologic properties and also in properties that reflect enzyme structure. This fetal intestinal-type alkaline phosphatase was not found in 24 specimens of normal liver from adults. The relevance of fetal intestinal-type alkaline phosphatase to Kasahara isoenzyme and adult intestinal alkaline phosphatase is discussed. The fetal and adult intestinal alkaline phosphatases differ in electrophoretic mobility, heat stability, and reactivity with concanavalin A. The adult-type enzyme has two components; only the electrophoretically slower, neuraminidase-resistant one is described here.

Hypophosphatasia (adult form): quantitation of serum alkaline phosphatase isoenzyme activity in a large kindred.

1980 ◽  
Vol 26 (7) ◽  
pp. 840-845 ◽  
Author(s):  
J L Millán ◽  
M P Whyte ◽  
L V Avioli ◽  
W H Fishman
Keyword(s):  
Alkaline Phosphatase ◽  
Serum Alkaline Phosphatase ◽  
Hepatic Metabolism ◽  
Total Activity ◽  
Heat Inactivation ◽  
Mean Values ◽  
Adult Form ◽  
Cellulose Acetate Membranes ◽  
Alkaline Phosphatase Isoenzymes ◽  
Alkaline Phosphatase Isoenzyme

Abstract We used heat inactivation, L-phenylalanine inhibition, and electrophoresis on polyacrylamide gel and cellulose acetate membranes--with and without use of specific antisera against the liver-bone, intestinal, and placental isoenzymes--to distinguish and quantitate the different alkaline phosphatase isoenzymes in sera from 23 adult members of a kindred affected by the adult form of hypophosphatasia. Nine subjects had values for total activity more than two standard deviations below the mean values for age- and sex-matched normal persons. Bone isoenzyme was diminished in all nine, whereas liver isoenzyme was subnormal in only four. Phosphoethanolamine and phosphoserine in the urine of eight hypophosphatasemic individuals correlated inversely with both total and liver alkaline phosphatase activity in their serum, but not with the activity of the bone isoenzyme. Total activity in the serum of adult kindred members correlated best with the circulating liver isoenzyme activity. The findings suggest that altered hepatic metabolism is responsible for the increased urinary excretion of phosphoethanolamine, and perhaps phosphoserine, in hypophosphatasia.

L-Phenylalanine inhibition of human alkaline phosphatases with p-nitrophenyl phosphate as substrate.

1982 ◽  
Vol 28 (12) ◽  
pp. 2426-2428 ◽  
Author(s):  
T Komoda ◽  
S Hokari ◽  
M Sonoda ◽  
Y Sakagishi ◽  
T Tamura
Keyword(s):  
Alkaline Phosphatase ◽  
Human Placenta ◽  
Placental Alkaline Phosphatase ◽  
Specific Inhibition ◽  
Human Intestine ◽  
Alkaline Phosphatases ◽  
Substrate Complex ◽  
Nitrophenyl Phosphate ◽  
Organ Specific ◽  
Alkaline Phosphatase Isoenzyme

Abstract With p-nitrophenyl phosphate as the substrate, there reportedly is no organ-specific inhibition of alkaline phosphatase (EC 3.1.3.1) activity by L-phenylalanine. However, we found that at pH 10.0, with p-nitrophenyl phosphate as the substrate, L-phenylalanine obviously inhibits the alkaline phosphatase isoenzyme from human placenta, whereas there is little if any inhibition of the isoenzyme from human intestine. Because of the differing effects of substrates (p-nitrophenyl phosphate and phenyl phosphate) and their enzymic products (p-nitrophenol and phenol) for L-phenylalanine action on the placental alkaline phosphatase isoenzyme, we suggest that the isoenzyme--inhibitor--substrate complex and the effect of released phosphate on L-phenylalanine inhibition of the isoenzyme activity differ from each other.

scholarly journals Synthesis and secretion of alkaline phosphatase in vitro from first-trimester and term human placentas

1981 ◽  
Vol 194 (3) ◽  
pp. 857-866 ◽  
Author(s):  
H Galski ◽  
S E Fridovich ◽  
D Weinstein ◽  
N De Groot ◽  
S Segal ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Time Course ◽  
De Novo ◽  
Placental Tissue ◽  
First Trimester ◽  
Alkaline Phosphatases ◽  
Heat Stable ◽  
Alkaline Phosphatase Isoenzymes ◽  
Specific Activities

The synthesis and secretion of alkaline phosphatases in vitro by human placental tissue incubated in organ culture were studied. First-trimester placenta synthesizes and secretes two different alkaline phosphatase isoenzymes (heat-labile and heat-stable), whereas in term placenta nearly all the alkaline phosphatase synthesized and secreted is heat-stable. The specific activities of alkaline phosphatases in first-trimester and term placental tissue remain constant throughout the time course of incubation. In the media, specific activities increase with time. Hence, alkaline phosphatase synthesis seems to be the driving force for its own secretion. The rates of synthesis de novo and of alkaline phosphatases were measured. The specific radioactivities of the secreted alkaline phosphatases were higher than the corresponding specific radioactivities in the tissue throughout the entire incubation period. The intracellular distribution of the alkaline phosphatase isoenzymes was compared.

scholarly journals Origin of an Elevated Plasma Alkaline Phosphatase Activity in Non-Jaundiced Patients

1978 ◽  
Vol 15 (1-6) ◽  
pp. 86-90 ◽  
Author(s):  
H. J. W. Cleeve
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Nucleotidase Activity ◽  
Elevated Plasma ◽  
Phosphatase Activities ◽  
Alkaline Phosphatase Isoenzymes ◽  
Effect Of Treatment ◽  
Plasma Alkaline Phosphatase ◽  
Alkaline Phosphatase Isoenzyme

Summary Samples from 260 non-jaundiced patients with elevated plasma alkaline phosphatase activities were analysed for γ-glutamyltransferase and 5′-nucleotidase activity, and for alkaline phosphatase isoenzyme pattern. The plasma γ-glutamyltransferase activity was found to be a more sensitive index than that of plasma 5′-nucleotidase in confirming the presence of a liver component of the elevated plasma alkaline phosphatase. If the γ-glutamyltransferase level is normal it is probable that the increase in plasma alkaline phosphatase activity is of bone origin. However, an elevated γ-glutamyltransferase result does not exclude a bone component; in this situation plasma alkaline phosphatase isoenzymes should be estimated. The causes of elevated activities of plasma alkaline phosphatase, 5′-nucleotidase and γ-glutamyltransferase, found in this investigation were generally the same as those found by other workers. The effect of treatment by drugs on γ-glutamyltransferase, an inducible enzyme, needs more investigation.

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