Display options
Share it on

Plant Physiol. 1982 Aug;70(2):344-9. doi: 10.1104/pp.70.2.344.

Purine catabolism in plants : purification and some properties of inosine nucleosidase from yellow lupin (lupinus luteus L.) seeds.

Plant physiology

A Guranowski

Affiliations

  1. Institute of Biochemistry, Academy of Agriculture, Wo?y?ska 35, 60-637 Pozna?, Poland.

PMID: 16662492 PMCID: PMC1067146 DOI: 10.1104/pp.70.2.344

Abstract

Inosine nucleosidase (EC 3.2.2.2), the enzyme which hydrolyzes inosine to hypoxanthine and ribose, has been partially purified from Lupinus luteus L. cv. Topaz seeds by extraction of the seed meal with low ionic strength buffer, ammonium sulfate fractionation, and chromatography on aminohexyl-Sepharose, Sephadex G-100, and hydroxyapatite.Molecular weight of the native enzyme is 62,000 as judged by gel filtration. The inosine nucleosidase exhibits optimum activity around pH 8. Energy of activation for inosine hydrolysis estimated from Arrhenius plot is 14.2 kilocalories per mole. The K(m) value computed for inosine is 65 micromolar.AMONG THE INOSINE ANALOGS TESTED, THE FOLLOWING NUCLEOSIDES ARE SUBSTRATES FOR THE LUPIN INOSINE NUCLEOSIDASE: xanthosine, purine riboside (nebularine), 6-mercaptopurine riboside, 8-azainosine, adenosine, and guanosine. The ratio of the velocities measured at 500 micromolar concentration of inosine, adenosine, and guanosine was 100:11:1, respectively. Specificity (V(max)/K(m)) towards adenosine is 48 times lower than that towards inosine.In contrast to the adenosine nucleosidase activity which is absent from lupin seeds and appears in the cotyledons during germination (Guranowski, Pawełkiewicz 1978 Planta 139: 245-247), the inosine nucleosidase is present in both lupin seeds and seedlings.

References

  1. Plant Physiol. 1978 Dec;62(6):871-4 - PubMed
  2. J Biol Chem. 1956 Sep;222(1):259-70 - PubMed
  3. Arch Biochem Biophys. 1973 Aug;157(2):380-7 - PubMed
  4. Biochem J. 1980 Jan 15;186(1):343-50 - PubMed
  5. Acta Biochim Pol. 1955;2(3):279-96 - PubMed
  6. Can J Microbiol. 1975 May;21(5):633-38 - PubMed
  7. Tropenmed Parasitol. 1975 Mar;26(1):19-26 - PubMed
  8. J Biol Chem. 1963 Oct;238:3358-61 - PubMed
  9. J Biol Chem. 1957 Mar;225(1):77-86 - PubMed
  10. Biochim Biophys Acta. 1977 May 12;482(1):145-58 - PubMed
  11. J Biol Chem. 1952 Oct;198(2):683-94 - PubMed
  12. Biochim Biophys Acta. 1968 Aug 20;162(2):230-42 - PubMed
  13. Biochem J. 1964 May;91(2):222-33 - PubMed
  14. Arch Biochem Biophys. 1979 Aug;196(1):220-6 - PubMed
  15. Comp Biochem Physiol B. 1976;54(2):239-42 - PubMed
  16. Plant Physiol. 1971 Feb;47(2):246-51 - PubMed
  17. Biochem J. 1966 Jan;98(1):198-203 - PubMed
  18. Biochem J. 1969 Nov;115(2):129-33 - PubMed
  19. Biochemistry. 1981 Jan 6;20(1):110-5 - PubMed
  20. J Biol Chem. 1970 Jun;245(12):3059-65 - PubMed
  21. J Biol Chem. 1956 Nov;223(1):535-49 - PubMed
  22. Plant Physiol. 1980 Dec;66(6):1091-4 - PubMed
  23. Eur J Biochem. 1977 Nov 1;80(2):517-23 - PubMed
  24. Can J Microbiol. 1968 Apr;14(4):377-83 - PubMed
  25. Comp Biochem Physiol B. 1982;71(3):483-8 - PubMed
  26. Biochem J. 1961 Apr;79:147-51 - PubMed
  27. Biochim Biophys Acta. 1979 Jul 11;569(1):13-22 - PubMed
  28. J Biol Chem. 1979 Sep 10;254(17):8185-93 - PubMed
  29. FEBS Lett. 1979 Aug 1;104(1):95-8 - PubMed
  30. Nucleic Acids Res. 1975 Jan;2(1):101-11 - PubMed
  31. Eur J Biochem. 1981 Feb;114(2):293-9 - PubMed
  32. Tropenmed Parasitol. 1978 Dec;29(4):435-8 - PubMed
  33. Biochem Biophys Res Commun. 1973 Sep 5;54(1):147-54 - PubMed
  34. Plant Physiol. 1959 Mar;34(2):153-8 - PubMed
  35. Nature. 1966 Mar 5;209(5027):1027-8 - PubMed
  36. Arch Biochem Biophys. 1967 Mar;119(1):356-62 - PubMed

Publication Types