scispace - formally typeset
Search or ask a question
Topic

Alkaline phosphatase

About: Alkaline phosphatase is a research topic. Over the lifetime, 20218 publications have been published within this topic receiving 540547 citations. The topic is also known as: Alkaline_phosphatase & IPR001952.


Papers
More filters
Journal ArticleDOI
TL;DR: The bound scFv(FRP5)–PhoA protein can be detected directly on tumor cells using a substrate for alkaline phosphatase, showing that the chimeric protein retains both binding and enzymatic activity.
Abstract: We have constructed genes expressing single-chain antigen binding proteins (scFv) which recognize the human erbB-2 receptor. These genes encode the heavy and light chain variable domains of an erbB-2 receptor specific monoclonal antibody, MAb FRP5, connected by a peptide linker. In order to express a bifunctional molecule, a bacterial alkaline phosphatase gene was fused 3' to the scFv gene. The scFv(FRP5) and scFv(FRP5)-alkaline phosphatase fusion protein (scFv(FRP5)-PhoA) expressed in E. coli specifically recognize the human erbB-2 protein and compete with MAb FRP5 for binding to the receptor. The bound scFv(FRP5)-PhoA protein can be detected directly on tumor cells using a substrate for alkaline phosphatase, showing that the chimeric protein retains both binding and enzymatic activity.

172 citations

Journal ArticleDOI
TL;DR: It is shown that this relationship accounts satisfactorily for the well-known effect of varying substrate concentration on optimum pH and velocity, and it is postulated that the conformational change is associated with a change in pK of two basic groups in the enzyme.
Abstract: 1. The effects of varying pH, ionic strength and temperature on the parameters K(m) and V(max.) for a purified alkaline phosphatase from calf intestinal mucosa with a new fluorogenic substrate, 4-methylumbelliferyl phosphate monoester disodium salt, and an ammediol-hydrochloric acid buffer system were determined. 2. It was found that, under varying conditions, a relationship exists between K(m) and V(max.) such that V(max.)=beta/(1+alpha/K(m)), where alpha and beta are constants, temperature- and ionic strength-dependent, but pH-independent. It is shown that this relationship accounts satisfactorily for the well-known effect of varying substrate concentration on optimum pH and velocity. 3. The various results are interpreted in terms of a pH-dependent conformational equilibrium between two forms of the enzyme, E(1) and E(2). Only E(1) combines with substrate, and only E(2) reacts to give inorganic phosphate. 4. To account for the pH-variation of K(m) and V(max.) in terms of this theory, it is postulated that the conformational change is associated with a change in pK of two basic groups in the enzyme.

172 citations

Journal ArticleDOI
TL;DR: It is demonstrated that also alkaline phosphatase derived from calf intestine (CIAP) is able to detoxify LPS, and potentially encompasses a novel therapeutic agent in the treatment of LPS-mediated diseases.
Abstract: It has been demonstrated that human placental alkaline phosphatase (HPLAP) attenuates the lipopolysaccharide (LPS)-mediated inflammatory response, likely through dephosphorylation of the lipid A moiety of LPS. In this study, it is demonstrated that also alkaline phosphatase derived from calf intestine (CIAP) is able to detoxify LPS. In mice administered CIAP, 80% of the animals survived a lethal Escherichia coli infection. In piglets, previous to LPS detoxification, the pharmacokinetic behavior of CIAP was studied. CIAP clearance was shown to be dose-independent and showed a biphasic pattern with an initial t1/2 of 3 to 5 min and a second phase t1/2 of 2 to 3 h. Although CIAP is cleared much faster than HPLAP, it attenuates LPS-mediated effects on hematology and tumor necrosis factor-alpha responses at doses up to 10 microg/kg in piglets. LPS-induced hematological changes were antagonized, and the tumor necrosis factor-alpha response was reduced up to 98%. Daily i.v. bolus administration of 4000 units CIAP, the highest dose used in the LPS intervention studies, in piglets for 28 days was tolerated without any sign of toxicity. Therefore, CIAP potentially encompasses a novel therapeutic agent in the treatment of LPS-mediated diseases. Based on the data mentioned above, human clinical trials have been initiated.

171 citations

Journal ArticleDOI
01 Sep 1972-Gut
TL;DR: The apparent effect of certain drugs on serum GGT activity indicates the need for caution in interpreting the results of this test, and patients who had been treated with phenytoin and barbiturates were found to have elevated serum G GT activities without any other evidence of liver disease.
Abstract: Serum γ-glutamyl transpeptidase (GGT) activity correlates closely with the activities of alkaline phosphatase (ALP) and 5′-nucleotidase (5NT) in various forms of liver disease. Maximum elevations of all three enzyme activities are observed in diseases which particularly affect the biliary tract. Compared with the other two enzymes GGT is generally increased to a greater extent and is thus the most sensitive indicator of biliary-tract disease, while estimations of serum GGT are more reproducible than those of 5NT. However, a group of patients who had been treated with phenytoin and barbiturates were found to have elevated serum GGT activities without any other evidence of liver disease. The apparent effect of certain drugs on serum GGT activity indicates the need for caution in interpreting the results of this test.

171 citations


Network Information
Related Topics (5)
Cell culture
133.3K papers, 5.3M citations
84% related
Apoptosis
115.4K papers, 4.8M citations
80% related
Oxidative stress
86.5K papers, 3.8M citations
80% related
Gene expression
113.3K papers, 5.5M citations
80% related
Antibody
113.9K papers, 4.1M citations
80% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
2023795
20221,761
2021271
2020302
2019294