Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
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Target Concepts:
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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)
Phospholipase A2 activity is raised in non-lesional psoriatic epidermis compared with normal epidermis. It has been shown that the activity of this enzyme is controlled by an inhibitory protein the inhibitory effect of which is increased by dephosphorylation. Treatment of epidermal extracts with
alkaline phosphatase
reduced the
phospholipase A2
activity, both in normal and in lesion-free psoriatic epidermis. Inclusion of pyrophosphate, a protein phosphatase inhibitor, in the homogenizing medium caused the activity of
phospholipase A2
in epidermal extracts from normal and lesion-free epidermis to be raised to the same high level. These results are consistent with the hypothesis that the raised
phospholipase A2
activity in psoriatic epidermis is due to hyperphosphorylation of an endogenous inhibitor as a result of defective control of a phosphorylation/dephosphorylation mechanism. The relevance of these findings to other work is discussed.
...
PMID:Modulation of phospholipase A2 activity in extracts of lesion-free psoriatic epidermis by alkaline phosphatase and a protein phosphatase inhibitor. 283 3
The
phospholipase A2
inhibitory activity of a 38 kDa K+-sensitive actin gelation factor in a murine leukemia cell line (M1) was examined. A specific antibody against 38 kDa protein was found to cross-react with 37 kDa protein (lipocortin) in rat peritoneal exudates. Although the native 38 kDa protein from M1 cells did not block
phospholipase A2
activity, pretreatment with
alkaline phosphatase
produced a form that did inhibit this enzyme. However, a purified 38 kDa protein from differentiated M1 cells blocked
phospholipase A2
activity without pretreatment with
alkaline phosphatase
. Phospholipase A2 inhibitory activity of the 38 kDa protein was not altered by addition of actin. These findings suggest that the
phospholipase A2
inhibitory of our 38 kDa protein was induced during differentiation. We also proposed that our 38 kDa protein has the same epitope as lipocortin.
...
PMID:Changes of phospholipase A2 inhibitory activity in the K+-sensitive actin gelation factor during the differentiation of myeloid leukemia cells. 295 92
Testosterone-treated calf thymocytes produce increased amounts of proteins, termed lipokinins, that stimulate
phospholipase A2
from snake venom and mammalian tissue. The induction of these proteins by testosterone is blocked by cycloheximide and, thus, requires new protein synthesis. These proteins activate
phospholipase A2
stoichiometrically. They are inactivated by boiling, trypsin or
alkaline phosphatase
but not by deoxyribonuclease or ribonuclease. Lipokinins significantly repair the failure of masculinization in the Tfm mouse with an X-linked deficiency of androgen-receptor. Thus, the post-receptor effects of testosterone on embryonic genitalia may be mediated through stimulation of
phospholipase A2
by lipokinins. Moreover, lipokinins may be involved as stimulators of the arachidonic acid cascade, as lipocortins are inhibitors.
...
PMID:John Lattimer lecture. Lipokinins: novel phospholipase A2 activators mediate testosterone effects on embryonic genitalia. 318 94
Third passage confluent cultures of cartilage cells, initially derived from the growth zone (GC) and resting zone (RC) of rat costochondral cartilage, were incubated with either 10(-11)-10(-8) M 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] or 10(-9)-10(-6) M 24,25-(OH)2D3. Plasma membranes and extracellular matrix vesicles were isolated, and specific activities of
phospholipase A2
and
alkaline phosphatase
were determined. The results demonstrate that the response to hormone is both cell and membrane specific. 1,25-(OH)2D3 produces an increase in GC matrix vesicle
alkaline phosphatase
and
phospholipase A2
specific activities at 10(-9) and 10(-8) M, but has no effect on these enzyme activities in RC membranes. RC cultured in 24,25-(OH)2D3 exhibit increased matrix vesicle
alkaline phosphatase
but decreased
phospholipase A2
activities at 10(-7) and 10(-6) M hormone. No effect on the RC plasma membrane enzymes or on GC plasma membrane or matrix vesicle enzymes was observed. The data suggest that changes in membrane fluidity due to
phospholipase A2
activity may play a role in regulating
alkaline phosphatase
activity in response to vitamin D metabolites and that this regulation in GC and RC may proceed by different mechanisms.
...
PMID:The effects of vitamin D metabolites on phospholipase A2 activity of growth zone and resting zone cartilage cells in vitro. 325 18
The proposed system of continuous monitoring of enzyme activities is based primarily on the electrochemical behaviour of thiol compounds, and the experimental equipment is extremely simple. The determination of cholinesterase (EC 3.1.1.8) activity is described. The normal values obtained for men (73.9, s +/- 10.3 microkat/l) and for women (71.1, s +/- 10.2 microkat/l), lie within the usual range of analogous photometric methods. Systems for determination of the activities of
alkaline phosphatase
(
EC 3.1.3.1
) and adenosylhomocysteinase (EC 3.3.1.1) are described. The activity of aspartate aminotransferase (EC 2.6.1.1) is determined by a combination of enzyme reactions, in which CoA is released from acetyl-CoA. Analogous procedures are discussed for determinations of alanine aminotransferase (EC 2.6.1.2), lactate dehydrogenase (EC 1.1.1.27), lipase (EC 3.1.1.2), and
phospholipase A2
(EC 3.1.1.4) activities, and for determination of substrates, e.g., acetate and carnitine. Possible determinations of an additional 199 enzyme activities and of some of substrates are suggested. By determining electrochemically active groups other than thiols this method becomes almost universally applicable.
...
PMID:New system of continuous monitoring of enzyme activities and determination of some substrates. 344 Aug 58
The anti-inflammatory activity of Cassia occidentalis leaf powder and an ethanol extract of Cardiospermum halicacabum aerial parts were assayed in male albino rats using carrageenan-induced rat paw edema. C. occidentalis was maximally active at a dose of 2000 mg/kg, while the C. halicacabum extract was maximally effective at a dose of 500 mg/kg. In the cotton pellet granuloma assay, these drugs were able to suppress the transudative, exudative and proliferative components of chronic inflammation. Further, these drugs were able to lower the lipid peroxide content and gamma-glutamyl transpeptidase and
phospholipase A2
activity in the exudate of cotton pellet granuloma. The increased
alkaline phosphatase
activity and decreased A/G ratio of plasma in cotton pellet granulomatous rats were normalized after treatment with these drugs. C. occidentalis powder and C. halicacabum extract were able to stabilize the human erythrocyte membrane against hypotonicity-induced lysis. It is likely that these drugs may exert their anti-inflammatory activity by inhibition of
phospholipase A2
, resulting in the reduced availability of arachidonic acid, a precursor of prostaglandin biosynthesis, and/or by stabilization of the lysosomal membrane system.
...
PMID:Biochemical modes of action of Cassia occidentalis and Cardiospermum halicacabum in inflammation. 361 9
The influence of two surface-active food additives on the integrity and permeability of rat ileal mucosa has been studied. We determined the activity of N-acetyl-beta-glucosaminidase, a lysosomal enzyme, in the rat intestinal lumen after deposition of polyoxyethylene (20) sorbitan monostearate (polysorbate 60; Tween 60) or polyoxyethylene (20) sorbitan monooleate (polysorbate 80; Tween 80) in a section of ligated, cannulated gut. We also determined the activities of N-acetyl-beta-glucosaminidase,
alkaline phosphatase
, 5'-nucleotidase and
phospholipase A2
in mixtures of isolated mucosal cells and polysorbate 60 or polysorbate 80. The activity of N-acetyl-beta-glucosaminidase was increased in the luminal contents of the cannulated gut 15 min after deposition of either polysorbate 60 or polysorbate 80 (10 mg/ml fluid instilled into gut). It was also increased in mixtures of mucosal cells and polysorbate 60 or polysorbate 80 (0.1-10 mg/ml). In contrast, the activities of
alkaline phosphatase
and 5'-nucleotidase were unaffected and that of
phospholipase A2
was decreased by the presence of either polysorbate. These findings indicated that polysorbate 60 and polysorbate 80 released lysosomal enzymes from the intestinal mucosal cells and that these agents might damage the intestinal mucosa and increase its permeability. We therefore determined the intestinal permeability to sodium fluorescein in the absence and presence of polysorbate 60 or 80 and found that the permeability was slightly increased in the presence of either of the compounds at concentrations of 10 mg/ml fluid instilled into gut. It is possible therefore that surface-active food additives might impair the function of the mucosal barrier and increase the permeability of the gut to potentially toxic and pathogenic molecules.
...
PMID:Influence of surface-active food additives on the integrity and permeability of rat intestinal mucosa. 609 20
1,2-Diacyl-sn-glycerol : CDPcholine cholinephosphotransferase (EC 2.7.8.2) and acyl-CoA : 1-acyl-sn-glycero-3-phosphocholine acyltransferase (EC 2.3.1.23) activities of rat liver microsomes can be inhibited by centrophenoxine (N,N-dimethylaminoethyl p-chlorophenoxyacetate). This inhibition is brought about by the intact centrophenoxine molecule rather than by the products of hydrolysis. A nonhydrolyzable ether analog of centrophenoxine was synthesized (neophenoxine; N,N-dimethylaminoethyl p-chlorophenoxyethyl ether) and proved most effective in inhibiting the two routes of phosphatidylcholine biosynthesis. While 50% inhibition of the cholinephosphotransferase was attained at 5 mM neophenoxine, 50% inhibition of the acyltransferase required 0.6 mM neophenoxine levels only. Inhibition of the cholinephosphotransferase (Ki approximately 1.5 mM) and the acyltransferase (Ki approximately 1 mM) by neophenoxine was shown to be noncompetitive. Other membrane-bound enzymes, such as glucose-6-phosphatase, monoacylglycerol lipase,
alkaline phosphatase
or
phospholipase A2
were not affected by the inhibitors. Because of this specificity, and because of the high affinity of the microsomal membrane for such agents, centrophenoxine and neophenoxine should prove useful for controlling phosphatidylcholine synthesis and for modulating the phosphatidylcholine deacylation-reacylation cycle.
...
PMID:Modulation of phosphatidylcholine synthesis in vitro. Inhibition of diacylglycerol cholinephosphotransferase and lysophosphatidylcholine acyltransferase by centrophenoxine and neophenoxine. 626 46
Splenic T lymphocytes of rats treated with complete Freund's adjuvant (CFA) spontaneously release a lymphokine that inhibits the glycosylation of IgE-binding factors during their biosynthesis and provides the factors with biologic activity: selective suppression of the IgE response. The lymphokine, which is called glycosylation-inhibiting factor, also prevents IgE-induced increases in Fc epsilon R+ cells. The glycosylation inhibiting factor is formed by stimulation of BCG-primed spleen cells with PPD and participates in the selective formation of IgE-suppressive factors. The lymphokine is derived from OX 8+ T cells in both the CFA and BCG systems. The glycosylation-inhibiting factor is a 16,000-dalton peptide, as estimated by gel filtration, and specifically binds to monoclonal antibody against lipomodulin, a phospholipase inhibitory protein. Furthermore, "lipomodulin" was detected by radioimmunoassay in the 16,000-dalton fraction that contained glycosylation inhibiting factor. The fraction did not inhibit
phospholipase A2
but after
alkaline phosphatase
treatment, the fraction did inhibit
phospholipase A2
. Furthermore, purified lipomodulin obtained from glucocorticoid-treated rabbit neutrophils had the same biologic activities as glycosylation inhibiting factors; i.e., it inhibited both protein glycosylation of IgE-binding factors and IgE-induced expression of Fc epsilon R. The results collectively indicate that glycosylation-inhibiting factor is a fragment of phosphorylated lipomodulin.
...
PMID:Modulation of the biologic activities of IgE-binding factors. I. Identification of glycosylation-inhibiting factor as a fragment of lipomodulin. 660 Feb 57
Lysophospholipase (EC 3.1.1.5) and
phospholipase A2
(EC 3.1.1.4) were determined in ileal mucosa from patients with Crohn's disease (CD) and non-inflammatory bowel diseases ( NIBD ). In addition, the activities of
alkaline phosphatase
, sucrase, maltase, and lactase were determined. The lysophospholipase activity, like that of
alkaline phosphatase
, sucrase and maltase, was decreased in affected areas of CD, whereas the
phospholipase A2
activity was rather increased. Lysophospholipase and
phospholipase A2
activities in apparently unaffected mucosa from CD patients were in between those in healthy mucosa from NIBD patients and those in affected mucosa from CD patients. These findings point to the possibility that the mucosal activity of lysophospholipase, like that of other brush border enzymes, is decreased in CD. This may render the mucosa less capable to handle lysolecithin, a potentially harmful agent formed in the intestine and known to induce inflammation in a number of experimental systems.
...
PMID:Decreased lysophospholipase and increased phospholipase A2 activity in ileal mucosa from patients with Crohn's disease. 672 69
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