Skip to main content
PMC home page
Plant Physiology logoLink to Plant Physiology
. 1991 Dec;97(4):1354–1358. doi: 10.1104/pp.97.4.1354

Fallover of Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase Activity 1

Decarbamylation of Catalytic Sites Depends on pH

Genhai Zhu 1,2, Richard G Jensen 1,2
PMCID: PMC1081171  PMID: 16668556

Abstract

Loss of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity during CO2 fixation, called fallover, occurred with or without loss of activator CO2 from catalytic sites depending on pH. At pH 7.5, but not at pH 8.5, the fraction of Rubisco sites that were carbamylated decreased during fallover. Inhibitors which formed during fallover were identified following NaBH4 reduction and separation of the products by high performance anion-exchange chromatography and pulsed amperometric detection. They were xylulose 1,5-bisphosphate (XuBP) and 3-ketoarabinitol 1,5-bisphosphate. During fallover at pH 8.5, 3-ketoarabinitol-P2 was the only inhibitor binding to Rubisco and this binding was at carbamylated sites, although both inhibitors were made. At pH 7.5, both inhibitors were bound to catalytic sites of Rubisco with XuBP bound tightly to decarbamylated sites, whereas 3-ketoarabinitol-P2 bound to carbamylated sites. The pH during fallover also influenced the ratio of 3-ketoarabinitol-P2 to XuBP formed. When fallover occurred at pH 7.5, both the formation of XuBP and its binding affinity to decarbamylated Rubisco sites were increased compared with those at pH 8.5. 3-Ketoribitol-P2 was not found at either pH.

Full text

PDF
1354

Selected References

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

  1. BYRNE W. L., LARDY H. A. Pentose phosphates formed by muscle aldolase. Biochim Biophys Acta. 1954 Aug;14(4):495–501. doi: 10.1016/0006-3002(54)90229-2. [DOI] [PubMed] [Google Scholar]
  2. Bahr J. T., Jensen R. G. Activation of ribulose bisphosphate carboxylase in intact chloroplasts by CO2 and light. Arch Biochem Biophys. 1978 Jan 15;185(1):39–48. doi: 10.1016/0003-9861(78)90141-8. [DOI] [PubMed] [Google Scholar]
  3. Edmondson D. L., Badger M. R., Andrews T. J. A Kinetic Characterization of Slow Inactivation of Ribulosebisphosphate Carboxylase during Catalysis. Plant Physiol. 1990 Aug;93(4):1376–1382. doi: 10.1104/pp.93.4.1376. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Edmondson D. L., Badger M. R., Andrews T. J. Slow Inactivation of Ribulosebisphosphate Carboxylase during Catalysis Is Caused by Accumulation of a Slow, Tight-Binding Inhibitor at the Catalytic Site. Plant Physiol. 1990 Aug;93(4):1390–1397. doi: 10.1104/pp.93.4.1390. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Edmondson D. L., Badger M. R., Andrews T. J. Slow Inactivation of Ribulosebisphosphate Carboxylase during Catalysis Is Not Due to Decarbamylation of the Catalytic Site. Plant Physiol. 1990 Aug;93(4):1383–1389. doi: 10.1104/pp.93.4.1383. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. McCurry S. D., Gee R., Tolbert N. E. Ribulose-1,5-bisphosphate carboxylase/oxygenase from spinach, tomato, or tobacco leaves. Methods Enzymol. 1982;90(Pt E):515–521. doi: 10.1016/s0076-6879(82)90178-1. [DOI] [PubMed] [Google Scholar]
  7. Paech C., Pierce J., McCurry S. D., Tolbert N. E. Inhibition of ribulose-1,5-biphosphate carboxylase/oxygenase by ribulose-1,5-bisphosphate epimerization and degradation products. Biochem Biophys Res Commun. 1978 Aug 14;83(3):1084–1092. doi: 10.1016/0006-291x(78)91506-1. [DOI] [PubMed] [Google Scholar]
  8. Pierce J., Tolbert N. E., Barker R. Interaction of ribulosebisphosphate carboxylase/oxygenase with transition-state analogues. Biochemistry. 1980 Mar 4;19(5):934–942. doi: 10.1021/bi00546a018. [DOI] [PubMed] [Google Scholar]
  9. Portis A. R., Salvucci M. E., Ogren W. L. Activation of Ribulosebisphosphate Carboxylase/Oxygenase at Physiological CO(2) and Ribulosebisphosphate Concentrations by Rubisco Activase. Plant Physiol. 1986 Dec;82(4):967–971. doi: 10.1104/pp.82.4.967. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Robinson S. P., Portis A. R. Ribulose-1,5-bisphosphate carboxylase/oxygenase activase protein prevents the in vitro decline in activity of ribulose-1,5-bisphosphate carboxylase/oxygenase. Plant Physiol. 1989 Jul;90(3):968–971. doi: 10.1104/pp.90.3.968. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Sue J. M., Knowles J. R. Ribulose-1,5-bisphosphate carboxylase: primary deuterium kinetic isotope effect using [3-2H]ribulose 1,5-bisphosphate. Biochemistry. 1982 Oct 26;21(22):5410–5414. doi: 10.1021/bi00265a005. [DOI] [PubMed] [Google Scholar]
  12. Zhu G., Jensen R. G. Status of the substrate binding sites of ribulose bisphosphate carboxylase as determined with 2-C-carboxyarabinitol 1,5-bisphosphate. Plant Physiol. 1990 May;93(1):244–249. doi: 10.1104/pp.93.1.244. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Zhu G., Jensen R. G. Xylulose 1,5-Bisphosphate Synthesized by Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase during Catalysis Binds to Decarbamylated Enzyme. Plant Physiol. 1991 Dec;97(4):1348–1353. doi: 10.1104/pp.97.4.1348. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Plant Physiology are provided here courtesy of Oxford University Press

RESOURCES