Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Isatin (15-25 mM) inhibited rat brush border sucrase by 40% in presence of Na+ and the inhibition was enhanced to over 60% in sodium free medium. Sucrase inhibition by isatin was dependent on pH. Kinetic analysis revealed a pure capacity type (Vmax-effect) inhibition of sucrase activity by isatin in presence of sodium. But it changed to affinity type (K-effect) in sodium free medium. The value of Ki was around 20-25 mM under these conditions. Enzyme inhibition by isatin was alleviated by increasing Na+ or sucrose concentrations. Other monovalent cations like K+, Li+ and Cs+ were also effective in restoring the enzyme activity to control levels. The effectiveness of the metal ions in alleviating the enzyme inhibition was in the order of Na+ > Cs+ > K+ > Li+.
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PMID:Inhibition of brush border sucrase by indoline 2,3-dione (isatin) in rat small intestine. 781 38

Isatin (10 mM) inhibited the activity of rabbit brush border sucrase by 60% at pH 5.0 but it had no effect on enzyme activity around neutral pH. Isatin inhibition of sucrase was unaffected by Na+ ions but K+ and Cs+ ions reduced enzyme inhibition, partially. Kinetic analysis revealed that sucrase inhibition by isatin at acidic pH was non-competitive with Ki of the order 6.5-7.8 mM. Isatin together with 4 mM harmaline or iodoacetate (3 mM) or dithionitrobenzene (2 mM) yielded 80-85% inhibition of the enzyme. These observations suggest that inhibitory sites for isatin, harmaline and -SH group reacting agents are distinct in rabbit brush border sucrase.
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PMID:Inhibition of rabbit intestinal brush border sucrase by indolin 2,3-dione (isatin) at pH 5.0. 795 45