PT  - JOURNAL ARTICLE
AU  - Pachter, J A
TI  - Noncompetitive inhibition of inositol monophosphatase by K-76 monocarboxylic acid.
DP  - 1991 Jul 01
TA  - Molecular Pharmacology
PG  - 107--111
VI  - 40
IP  - 1
4099  - http://molpharm.aspetjournals.org/content/40/1/107.short
4100  - http://molpharm.aspetjournals.org/content/40/1/107.full
SO  - Mol Pharmacol1991 Jul 01; 40
AB  - K-76COONa, a fungal product that was previously isolated for its inhibition of complement activation, was found to inhibit myo-inositol monophosphatase activity. K-76COONa was slightly more potent than lithium, with a Ki of approximately 0.5 mM. Kinetic analyses with D-myo-inositol 1-phosphate as the substrate showed that myo-inositol monophosphatase inhibition by K-76COONa was noncompetitive relative to substrate but competitive with activation by magnesium. Higher concentrations of K-76COONa were necessary to inhibit myo-[3H]inositol 1,4-bisphosphate hydrolysis by inositol 1,4-bisphosphate/inositol 1,3,4-trisphosphate 1-phosphatase (IC50 = approximately 7.5 mM). K-76COONa may be useful for further investigation of the mechanism of myo-inositol monophosphatase and for determination of whether inhibition of this enzyme plays a role in the therapeutic effectiveness of lithium in treatment of affective disorders.