Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.53 (sialidase)
 2,694 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Treatment with cholecalciferol or 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) increases activity and changes electrophoretic mobility of alkaline phosphatase (alkPase) from duodenal brush border of vitamin D-deprived chicks. Three of the four molecular forms of the enzyme show reduced velocity of migration 9 h after 1,25(OH)2D3 or 24 h after vitamin D3. This change is reversed about 48 h later, when mobility of those bands is higher than that of controls. Incubation of enzyme preparations with exogenous neuraminidase produces the same electrophoretic modifications observed during the early stage, indicating that they are due to desialylation. Cholecalciferol or 1,25(OH)2D3 increase sialidase activity of duodenal brush border. This increment precedes that of alkPase and could account for the initial desialylation and moderate rise of alkPase. Cycloheximide markedly reduces alkPase in rachitic chicks and blocks the increase of the enzyme activity produced by vitamin D3, but does not modify the rise of sialidase or the reduction of alkPase electrophoretic mobility. The bimodal response of alkPase to 1,25(OH)2D3 or cholecalciferol comprises two different mechanisms: during a first stage, epigenetic modifications of preexisting enzyme can be triggered by the increased Ca2+ levels; in a second phase, there is activation of enzyme synthesis.
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PMID:Changes of intestinal alkaline phosphatase produced by cholecalciferol or 1,25-dihydroxyvitamin D3 in vitamin D-deficient chicks. 299 Mar 44

Serum Gc protein (known as vitamin D(3)-binding protein) is the precursor for the principal macrophage-activating factor (MAF). The MAF precursor activity of serum Gc protein of prostate cancer patients was lost or reduced because Gc protein was deglycosylated by serum alpha-N-acetylgalactosaminidase (Nagalase) secreted from cancerous cells. Therefore, macrophages of prostate cancer patients having deglycosylated Gc protein cannot be activated, leading to immunosuppression. Stepwise treatment of purified Gc protein with immobilized beta-galactosidase and sialidase generated the most potent MAF (termed GcMAF) ever discovered, which produces no adverse effect in humans. Macrophages activated by GcMAF develop a considerable variation of receptors that recognize the abnormality in malignant cell surface and are highly tumoricidal. Sixteen nonanemic prostate cancer patients received weekly administration of 100 ng of GcMAF. As the MAF precursor activity increased, their serum Nagalase activity decreased. Because serum Nagalase activity is proportional to tumor burden, the entire time course analysis for GcMAF therapy was monitored by measuring the serum Nagalase activity. After 14 to 25 weekly administrations of GcMAF (100 ng/week), all 16 patients had very low serum Nagalase levels equivalent to those of healthy control values, indicating that these patients are tumor-free. No recurrence occurred for 7 years.
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PMID:Immunotherapy for Prostate Cancer with Gc Protein-Derived Macrophage-Activating Factor, GcMAF. 1863 61