Skip to main content
NCBI home page
Biochemical Journal logoLink to Biochemical Journal
. 1995 Apr 15;307(Pt 2):585–593. doi: 10.1042/bj3070585

Kinetic characterization of enzyme forms involved in metal ion activation and inhibition of myo-inositol monophosphatase.

F Strasser 1, P D Pelton 1, A J Ganzhorn 1
PMCID: PMC1136688  PMID: 7733900

Abstract

Activation and inhibition of recombinant bovine myo-inositol monophosphatase by metal ions was studied with two substrates, D,L-inositol 1-phosphate and 4-nitrophenyl phosphate. Mg2+ and Co2+ are essential activators of both reactions. At high concentrations, they inhibit hydrolysis of inositol 1-phosphate, but not 4-nitrophenyl phosphate. Mg2+ is highly selective for inositol 1-phosphate (kcat. = 26 s-1) compared with the aromatic substrate (kcat. = 1 s-1), and follows sigmoid activation kinetics in both cases. Co2+ catalyses the two reactions at similar rates (kcat. = 4 s-1), but shows sigmoid activation only with the natural substrate. Li+ and Ca2+ are uncompetitive inhibitors with respect to inositol 1-phosphate, but non-competitive with respect to 4-nitrophenyl phosphate. Both metal ions are competitive inhibitors with respect to Mg2+ with 4-nitrophenyl phosphate as the substrate. With inositol 1-phosphate, Ca2+ is competitive and Li+ non-competitive with respect to Mg2+. Multiple inhibition studies indicate that Li+ and Pi can bind simultaneously, whereas no such complex was detected with Ca2+ and Pi. Several sugar phosphates were also characterized as substrates of myo-inositol monophosphatase. D-Ribose 5-phosphate is slowly hydrolysed (kcat. = 3 s-1), but inhibition by Li+ is very efficient (Ki = 0.15 mM), non-competitive with respect to the substrate and competitive with respect to Mg2+. Depending on the nature of the substrate, Li+ inhibits by preferential binding to free enzyme (E), the enzyme-substrate (E.S) or the enzyme-phosphate (E.Pi) complex. Ca2+, on the other hand, inhibits by binding to E and E.S, in competition with Mg2+. The results are discussed in terms of a catalytic mechanism involving two metal ions.

Full text

PDF
585

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Attwood P. V., Ducep J. B., Chanal M. C. Purification and properties of myo-inositol-1-phosphatase from bovine brain. Biochem J. 1988 Jul 15;253(2):387–394. doi: 10.1042/bj2530387. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Berridge M. J., Downes C. P., Hanley M. R. Neural and developmental actions of lithium: a unifying hypothesis. Cell. 1989 Nov 3;59(3):411–419. doi: 10.1016/0092-8674(89)90026-3. [DOI] [PubMed] [Google Scholar]
  3. Bone R., Frank L., Springer J. P., Atack J. R. Structural studies of metal binding by inositol monophosphatase: evidence for two-metal ion catalysis. Biochemistry. 1994 Aug 16;33(32):9468–9476. doi: 10.1021/bi00198a012. [DOI] [PubMed] [Google Scholar]
  4. Bone R., Frank L., Springer J. P., Pollack S. J., Osborne S. A., Atack J. R., Knowles M. R., McAllister G., Ragan C. I., Broughton H. B. Structural analysis of inositol monophosphatase complexes with substrates. Biochemistry. 1994 Aug 16;33(32):9460–9467. doi: 10.1021/bi00198a011. [DOI] [PubMed] [Google Scholar]
  5. Bone R., Springer J. P., Atack J. R. Structure of inositol monophosphatase, the putative target of lithium therapy. Proc Natl Acad Sci U S A. 1992 Nov 1;89(21):10031–10035. doi: 10.1073/pnas.89.21.10031. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Chirgwin J. M., Przybyla A. E., MacDonald R. J., Rutter W. J. Isolation of biologically active ribonucleic acid from sources enriched in ribonuclease. Biochemistry. 1979 Nov 27;18(24):5294–5299. doi: 10.1021/bi00591a005. [DOI] [PubMed] [Google Scholar]
  7. Cleland W. W. Statistical analysis of enzyme kinetic data. Methods Enzymol. 1979;63:103–138. doi: 10.1016/0076-6879(79)63008-2. [DOI] [PubMed] [Google Scholar]
  8. Diehl R. E., Whiting P., Potter J., Gee N., Ragan C. I., Linemeyer D., Schoepfer R., Bennett C., Dixon R. A. Cloning and expression of bovine brain inositol monophosphatase. J Biol Chem. 1990 Apr 15;265(11):5946–5949. [PubMed] [Google Scholar]
  9. Gani D., Downes C. P., Batty I., Bramham J. Lithium and myo-inositol homeostasis. Biochim Biophys Acta. 1993 Jun 30;1177(3):253–269. doi: 10.1016/0167-4889(93)90121-5. [DOI] [PubMed] [Google Scholar]
  10. Ganzhorn A. J., Chanal M. C. Kinetic studies with myo-inositol monophosphatase from bovine brain. Biochemistry. 1990 Jun 26;29(25):6065–6071. doi: 10.1021/bi00477a026. [DOI] [PubMed] [Google Scholar]
  11. Ganzhorn A. J., Vincendon P., Pelton J. T. Structural characterization of myo-inositol monophosphatase from bovine brain by secondary structure prediction, fluorescence, circular dichroism and Raman spectroscopy. Biochim Biophys Acta. 1993 Feb 13;1161(2-3):303–310. doi: 10.1016/0167-4838(93)90229-k. [DOI] [PubMed] [Google Scholar]
  12. Gee N. S., Ragan C. I., Watling K. J., Aspley S., Jackson R. G., Reid G. G., Gani D., Shute J. K. The purification and properties of myo-inositol monophosphatase from bovine brain. Biochem J. 1988 Feb 1;249(3):883–889. doi: 10.1042/bj2490883. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Greasley P. J., Gore M. G. Bovine inositol monophosphatase. Studies on the binding interactions with magnesium, lithium and phosphate ions. FEBS Lett. 1993 Sep 27;331(1-2):114–118. doi: 10.1016/0014-5793(93)80308-h. [DOI] [PubMed] [Google Scholar]
  14. Greasley P. J., Hunt L. G., Gore M. G. Bovine inositol monophosphatase. Ligand binding to pyrene-maleimide-labelled enzyme. Eur J Biochem. 1994 Jun 1;222(2):453–460. doi: 10.1111/j.1432-1033.1994.tb18885.x. [DOI] [PubMed] [Google Scholar]
  15. Hallcher L. M., Sherman W. R. The effects of lithium ion and other agents on the activity of myo-inositol-1-phosphatase from bovine brain. J Biol Chem. 1980 Nov 25;255(22):10896–10901. [PubMed] [Google Scholar]
  16. Kwok F., Wang X., Churchich J. E. Myo-inositol monophosphatase: binding of terbium and a cross-linking reagent to the catalytic site cavity. Arch Biochem Biophys. 1994 Sep;313(2):274–279. doi: 10.1006/abbi.1994.1388. [DOI] [PubMed] [Google Scholar]
  17. Leech A. P., Baker G. R., Shute J. K., Cohen M. A., Gani D. Chemical and kinetic mechanism of the inositol monophosphatase reaction and its inhibition by Li+. Eur J Biochem. 1993 Mar 15;212(3):693–704. doi: 10.1111/j.1432-1033.1993.tb17707.x. [DOI] [PubMed] [Google Scholar]
  18. McAllister G., Whiting P., Hammond E. A., Knowles M. R., Atack J. R., Bailey F. J., Maigetter R., Ragan C. I. cDNA cloning of human and rat brain myo-inositol monophosphatase. Expression and characterization of the human recombinant enzyme. Biochem J. 1992 Jun 15;284(Pt 3):749–754. doi: 10.1042/bj2840749. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Nahorski S. R., Ragan C. I., Challiss R. A. Lithium and the phosphoinositide cycle: an example of uncompetitive inhibition and its pharmacological consequences. Trends Pharmacol Sci. 1991 Aug;12(8):297–303. doi: 10.1016/0165-6147(91)90581-c. [DOI] [PubMed] [Google Scholar]
  20. Northrop D. B., Cleland W. W. The kinetics of pig heart triphosphopyridine nucleotide-isocitrate dehydrogenase. II. Dead-end and multiple inhibition studies. J Biol Chem. 1974 May 10;249(9):2928–2931. [PubMed] [Google Scholar]
  21. Parthasarathy L., Vadnal R. E., Parthasarathy R., Devi C. S. Biochemical and molecular properties of lithium-sensitive myo-inositol monophosphatase. Life Sci. 1994;54(16):1127–1142. doi: 10.1016/0024-3205(94)00835-3. [DOI] [PubMed] [Google Scholar]
  22. Pelton P. D., Ganzhorn A. J. The effect of histidine modification on the activity of myo-inositol monophosphatase from bovine brain. J Biol Chem. 1992 Mar 25;267(9):5916–5920. [PubMed] [Google Scholar]
  23. Pollack S. J., Atack J. R., Knowles M. R., McAllister G., Ragan C. I., Baker R., Fletcher S. R., Iversen L. L., Broughton H. B. Mechanism of inositol monophosphatase, the putative target of lithium therapy. Proc Natl Acad Sci U S A. 1994 Jun 21;91(13):5766–5770. doi: 10.1073/pnas.91.13.5766. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Pollack S. J., Knowles M. R., Atack J. R., Broughton H. B., Ragan C. I., Osborne S., McAllister G. Probing the role of metal ions in the mechanism of inositol monophosphatase by site-directed mutagenesis. Eur J Biochem. 1993 Oct 1;217(1):281–287. doi: 10.1111/j.1432-1033.1993.tb18244.x. [DOI] [PubMed] [Google Scholar]
  25. Webb M. R. A continuous spectrophotometric assay for inorganic phosphate and for measuring phosphate release kinetics in biological systems. Proc Natl Acad Sci U S A. 1992 Jun 1;89(11):4884–4887. doi: 10.1073/pnas.89.11.4884. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. YONETANI T., THEORELL H. STUDIES ON LIVER ALCOHOL HYDROGENASE COMPLEXES. 3. MULTIPLE INHIBITION KINETICS IN THE PRESENCE OF TWO COMPETITIVE INHIBITORS. Arch Biochem Biophys. 1964 Jul 20;106:243–251. doi: 10.1016/0003-9861(64)90184-5. [DOI] [PubMed] [Google Scholar]

Articles from Biochemical Journal are provided here courtesy of The Biochemical Society

RESOURCES