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)

A monoclonal antibody (H17E2) recognising both placental alkaline phosphatase (PLAP) and testicular PLAP-like alkaline phosphatase was incorporated in a solid phase immunoassay. This was used to measure levels of PLAP in 257 sera from 148 patients with germ cell neoplasms of the testis. High levels of PLAP were found in all patients with active seminomas (mean 0.85 O.D.) compared to those in clinical remission (mean 0.20 O.D.) (P less than 0.0001). More importantly, changing levels of PLAP correlated with the course of disease in 79 samples from 33 patients with seminoma (P less than 0.0001). Elevated PLAP levels were also noted in patients in remission who were smokers (mean 0.32 O.D.) compared to non-smokers (mean 0.15 O.D.) (P less than 0.001). These data demonstrate that determination of PLAP levels using this sensitive immunoassay is an important new adjunct in the monitoring of the response to treatment in patients with seminoma.
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PMID:Monoclonal antibody assay of serum placental alkaline phosphatase in the monitoring of testicular tumours. 399 8

Placental alkaline phosphatase (PLAP) in humans shows a high degree of genetic polymorphism as disclosed by electrophoretic analysis. Human testes contain trace amounts of a PLAP-like enzyme, that although immunologically cross-reactive with PLAP, shows unique catalytic properties. As an alternative approach to study enzyme polymorphism we have developed monoclonal antibodies to purified allelic variants of PLAP. Five different monoclonal antibodies are described in this report. The antibodies react with different epitopes on the PLAP molecule. Both conformational dependent and independent determinants are detected. Two epitopes are modified when comparing the S and F allelic variants of PLAP. One epitope is common to PLAP and the intestinal isoenzyme of alkaline phosphatase. The five epitopes appear to be mapped on two rather distant antigenic domains. Combinations of any two antibodies binding to different domains give immunoprecipitates with PLAP on Ouchterlony tests and give good response in sandwich enzyme-linked immunosorbent assays. A study of PLAP-like enzyme in 32 individual testis samples indicates differences in four of the epitopes when compared with PLAP. Four types of testicular enzymes can be distinguished based on their reactivities. These results indicate structural differences between the testicular PLAP-like enzyme and PLAP. These differences are compatible with an underlying genetic mechanism.
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PMID:Antigenic determinants of human placental and testicular placental-like alkaline phosphatases as mapped by monoclonal antibodies. 619 58

In Sinclair swine, there is an increase in alkaline phosphatase activity in spontaneously arising melanoma tumors when compared to normal skin. While alkaline phosphatase activity could be detected in melanomas from animals 1 day old, the maximum levels of alkaline phosphatase activity occurred in tumors from animals greater than 30 days old. The alkaline phosphatase was purified from cutaneous melanomas using chloroform precipitation, Phenyl-Sepharose chromatography, and concanavalin A Sepharose chromatography approximately 146-fold, with an overall recovery of 15%. The purified enzyme exhibited optimal activity over the pH range of 8.9-10.6. The apparent Km of the enzyme for p-nitrophenyl phosphate was 0.15 mM. The enzyme exhibited a relative mobility of 0.04 in nondenaturing polyacrylamide gels. The molecular weight of the enzyme was estimated by gel filtration chromatography to be 122,000 and it was composed of two identical subunits each having a molecular weight of 67,000. The enzyme was thermolabile at 56 degrees C (T50, 18 min) and its activity was inhibited by L-homoarginine, levamisole, and vanadate, but not by L-phenylalanine or L-phenylalanylglycylglycine. These characteristics distinguished the enzyme from the intestinal isoenzyme that is found in normal swine skin but were similar to those exhibited by the porcine placental isoenzyme of alkaline phosphatase. These results suggest that the development of malignant melanoma in Sinclair swine is accompanied by the expression of a placental-like alkaline phosphatase activity.
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PMID:Properties of an alkaline phosphatase from Sinclair swine melanoma. 651 73

Human testes contain trace amounts of heat-stable placental-like alkaline phosphatase. Using a recently described allotype-specific monoclonal antibody (F11) toward placental alkaline phosphatase (PLAP), we show that the frequencies of reactivity of the testis enzymes differ greatly from those of the placental phenotypes. By means of the enzyme inhibitors L-Phe, L-Phe-gly-gly, L-Leu, and L-Leu-gly-gly, the testis enzyme can be clearly distinguished in all cases from the placental enzyme. These results argue that the testis enzyme is not a product of the placental gene and suggest the possible existence of a new locus of alkaline phosphatase.
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PMID:A possible new locus of alkaline phosphatase expressed in human testis. 716 3

BeWo choriocarcinoma cells synthesize two alkaline phosphatase isoenzymes: germ-cell alkaline phosphatase and tissue-unspecific alkaline phosphatase. We have made use of the differential heat-stabilities of these two isoenzymes to study the induction of germ-cell alkaline phosphatase by sodium butyrate and cyclic AMP (cAMP). Sodium butyrate causes a large induction of germ-cell alkaline phosphatase activity (approx. 35-fold after 96 h) after an initial lag period of 12-24 h. We showed that butyrate increases germ-cell alkaline phosphatase mRNA. Dibutyryl cAMP also induces germ cell alkaline phosphatase (approx. 2.5-fold after 96 h). When optimal concentrations of butyrate and dibutyryl cAMP were added simultaneously to cells, they caused a synergistic induction of activity. This suggested that these compounds use separate mechanisms to induce germ-cell alkaline phosphatase activity and that it is the cAMP moiety of dibutyryl cAMP that induces enzyme activity. This was confirmed by the use of two additional cAMP analogues, 8-(4-chlorophenylthio) cAMP and 8-bromo cAMP, and of two compounds, 3-methyl-1-isobutylxanthine and cholera toxin, which raise the endogenous concentration of cAMP. All four compounds caused a 2-fold increase in enzyme activity. Treatment of cells with 8-(4-chlorophenylthio) cAMP, 8-bromo cAMP and cholera toxin increased germ-cell alkaline phosphatase mRNA between 2- and 7-fold. These data suggest that this alkaline phosphatase isoenzyme is regulated at the level of its mRNA by cAMP, in a manner distinct from that of butyrate.
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PMID:Induction of germ-cell alkaline phosphatase by butyrate and cyclic AMP in BeWo choriocarcinoma cells. 750 59

Human seminal alkaline phosphatase was investigated with respect to its electrophoretic mobility, heat lability, and susceptibility to inhibition by phenylalanine, tartrate, and homoarginine. Total alkaline phosphatase activity in 30 samples of human semen was measured colorimetrically, using p-nitrophenylphosphate as substrate. Using linear regression analysis, no significant correlation was found between the enzyme activity and the sperm count, sperm motility, semen volume, and the concentrations of seminal inositol and fructose. The alkaline phosphatase activity was higher in the earlier portion of split ejaculate samples. Sodium DL-tartrate (42 mmol/l), which inhibits acid phosphatase, did not inhibit seminal alkaline phosphatase significantly. L-Homoarginine (10 mmol/l), an inhibitor of the liver and bone isoenzymes, inhibited the seminal enzyme (53%), whereas L-phenylalanine (12 mmol/l), a strong inhibitor of placental alkaline phosphate, decreased activity by about 10%. Electrophoresis of semen samples on agarose revealed a broad band which was not sharpened after treatment with neuraminidase. Semen total alkaline phosphatase was essentially totally inactivated by heating at 56 degrees C for 15 min or 10 min at 65 degrees C; similar behaviour has been reported for the liver and bone isoenzymes. Electrophoresis after heating did not reveal a residual band of heat-stable placental-like alkaline phosphatase. Semen alkaline phosphatase appears to contain more than one isoenzyme, but placental-like alkaline phosphatase cannot be more than a minor component.
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PMID:Alkaline phosphatase in human semen: an investigation using enzyme inhibitors and gel electrophoresis. 813 13

Surgical biopsies and fine-needle aspirates of peri-tumoural seminiferous tubules were taken from freshly-excised orchidectomy specimens. In addition, patients with suspected germ cell tumour provided a peri-operative sample of seminal fluid. All three tissue preparations were investigated using flow cytometry, immunochemistry for placental-like alkaline phosphatase and enzymochemistry for alkaline phosphatase. Biopsy and fine-needle aspiration cytology provide the greatest diagnostic accuracy for carcinoma-in-situ using these techniques. Seminal fluid analysis did not provide a satisfactory diagnostic yield in the series of patients presented. A seminal plasma placental-like alkaline phosphatase immunoassay failed to discriminate CIS because of the high level of background germ cell alkaline phosphatase.
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PMID:Seminal fluid analysis and fine-needle aspiration cytology in the diagnosis of carcinoma in situ of the testis. 838 41

An immunohistopathological study using monoclonal antibodies for alkaline phosphatases demonstrated placental alkaline phosphatase (PLAP)-like substance in the tumor cells of 11 pure seminomas, 1 seminoma with embryonal carcinoma and 1 seminoma metastasis. Liver alkaline phosphatase (LAP) could also be demonstrated in all seminomas but a third intestinal alkaline phosphatase (IAP) was not demonstrable in any tumor. The PLAP-like substance and LAP had considerable enzyme activities. This provides two tumor markers of seminomas detectable in histopathological specimens.
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PMID:Immunopathology of alkaline phosphatase isozymes in seminoma. 843 23

Two members of a placental alkaline phosphatase (PLAP) family, PLAP and PLAP-like or germ cell alkaline phosphatase, are aberrantly expressed in tumors of ecotropic origin. To characterize alkaline phosphatase induced in seminoma, alkaline phosphatase cDNA clones were isolated from a cDNA library constructed from seminoma cells and characterized by nucleotide sequence determination. Thus, isolated cDNA clones were classified into two types, germ cell alkaline phosphatase (PLAP-like) and liver/bone/kidney-type alkaline phosphatase (L/B/K AP). These results suggest that other than the PLAP family members, the expression of L/B/K AP is enhanced in seminoma and can serve as a tumor marker in seminoma.
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PMID:Characterization of alkaline phosphatase genes expressed in seminoma by cDNA cloning. 982 15

A case of endometrioid ovarian carcinoma associated with elevated levels of serum placental-like alkaline phosphatase (PLAP) is presented. Two and a half years before a final diagnosis was made following explorative laparotomy, an incidental blood test revealed elevated alkaline phosphatase in the patient's serum. A thorough investigation for the source of this elevation was negative. Postoperative immunohistochemical staining of the tumor, showed diffuse stain with PLAP, along with gradual decline to normal values of serum total alkaline phosphatase. It is suggested, that whenever serum alkaline phosphatase is elevated due to unknown reason, an investigation including alkaline phosphatase isoenzymes, serum Ca-125, trans-vaginal pelvic sonogram and even diagnostic laparoscopy, should be considered in a search for early preclinical ovarian cancer.
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PMID:Elevated serum alkaline phosphatase may enable early diagnosis of ovarian cancer. 1047 Nov 45


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