Home LiteratureArticle Details
PMID: 16660503 Published · ppublish English Journal Article

6-Phosphogluconate Dehydrogenase Isoenzymes from the Developing Endosperm of Ricinus communis L.

Plant physiology ·Vol. 62 ·No. 2 ·1978-08-00 ·Pages 287-90

Simcox PD, Dennis DT

Abstract

The cytosolic and proplastid isoenzymes of 6-phosphogluconate dehydrogenase were purified from the developing endosperm of the castor bean (Ricinis communis L.). No differences in physical or kinetic properties were found for the purified isoenzymes. Each was composed of two identical 55,000 subunits. They had identical pH optima of 7.8 to 8.0 and similar MgCl(2) stimulation for the oxidative decarboxylation of 6-phosphogluconate. The Km values for 6-phosphogluconate were 12 and 9.6 micromolar and for NADP(+) were 4.1 and 5.4 micromolar for the cytosolic and proplastid isoenzymes, respectively. Therefore, the synthesis of two distinct 6-phosphogluconate dehydrogenase isoenzymes does not appear to have any kinetic significance for the developing seed. However, changes in the proplastid contribution toward carbohydrate metabolism occur in the developing seed and may necessitate independent gene expression to allow for a unique and flexible subcellular distribution of isoenzymes during development.

Authors & Affiliations
2 authors, click to expand affiliations / ORCID
Simcox P D
Department of Biology, Queen's University, Kingston, Ontario, K7L 3N6 Canada.
Dennis D T
References (22)
22 references, click to expand
  1. Chloroplast and cytoplasmic enzymes: three distinct isoenzymes associated with the reductive pentose phosphate cycle.
    Plant Physiol. 1970 May;45(5):583-5 PMID: 16657347
  2. Gradient sievorptive chromatography. A focusing system for the separation of cellular components.
    Biochemistry. 1973 Sep 11;12(19):3627-32 PMID: 4596145
  3. Development and intracellular distribution of enzymes of the oxidative pentose phosphate cycle in radish cotyledons.
    Plant Physiol. 1975 Dec;56(6):836-40 PMID: 16659405
  4. Pyruvate dehydrogenase complex activity in proplastids and mitochondria of developing castor bean endosperm.
    Biochem Biophys Res Commun. 1975 Jan 6;62(1):42-7 PMID: 1111514
  5. 6-Phosphogluconate dehydrogenase. Purification and kinetics.
    J Biol Chem. 1976 Nov 25;251(22):7127-31 PMID: 11218
  6. Purification and properties of 6-phosphogluconate dehydrogenase from rabbit mammary gland.
    Biochem J. 1975 Nov;151(2):263-70 PMID: 3163
  7. Soluble and particulate glycolysis in developing castor bean endosperm.
    Biochem Biophys Res Commun. 1975 Jan 2;64(3):970-5 PMID: 125088
  8. Isoenzymes of the Glycolytic and Pentose Phosphate Pathways in Proplastids from the Developing Endosperm of Ricinis communis L.
    Plant Physiol. 1978 Jun;61(6):871-7 PMID: 16660415
  9. STARCH-GEL ELECTROPHORESIS--APPLICATION TO THE CLASSIFICATION OF PITUITARY PROTEINS AND POLYPEPTIDES.
    Metabolism. 1964 Oct;13:SUPPL:985-1002 PMID: 14228777
  10. Chloroplast phosphofructokinase: I. Proof of phosphofructokinase activity in chloroplasts.
    Plant Physiol. 1977 Aug;60(2):290-4 PMID: 16660078
  11. Two isoenzymes each of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase in spinach leaves.
    Arch Biochem Biophys. 1973 Jan;154(1):438-48 PMID: 4144057
  12. DISC ELECTROPHORESIS. II. METHOD AND APPLICATION TO HUMAN SERUM PROTEINS.
    Ann N Y Acad Sci. 1964 Dec 28;121:404-27 PMID: 14240539
  13. Chloroplast aldolase is controlled by a nuclear gene.
    Plant Physiol. 1970 Dec;46(6):819-20 PMID: 5500208
  14. Estimation of molecular radius, free mobility, and valence using polyacylamide gel electrophoresis.
    Anal Biochem. 1971 Mar;40(1):95-134 PMID: 5550151
  15. Enzymes of the Glycolytic and Pentose Phosphate Pathways in Proplastids from the Developing Endosperm of Ricinus communis L.
    Plant Physiol. 1977 Jun;59(6):1128-32 PMID: 16660007
  16. Cell-free synthesis of leaf protein: Identification of an apparent precursor of the small subunit of ribulose-1,5-bisphosphate carboxylase.
    Proc Natl Acad Sci U S A. 1978 Feb;75(2):655-9 PMID: 16592495
  17. Two isoenzymes of glucosephosphate isomerase from spinach leaves and their intracellular compartmentation.
    Eur J Biochem. 1974 Jun 1;45(1):77-82 PMID: 4421522
  18. Isoenzyme of pyruvate kinase in proplastids from developing castor bean endosperm.
    Plant Physiol. 1978 Jun;61(6):1037-9 PMID: 16660412
  19. Inhibition of phosphoglucose isomerase.
    Nature. 1956 Dec 22;178(4547):1401 PMID: 13387725
  20. Observations on molecular weight determinations on polyacrylamide gel.
    J Biol Chem. 1969 Sep 25;244(18):5074-80 PMID: 5824577
  21. Role of Aldolase in Photosynthesis. II Demonstration of Aldolase Types in Photosynthetic Organisms.
    Plant Physiol. 1968 May;43(5):793-8 PMID: 16656841
  22. Chloroplast and Cytoplasmic Enzymes: IV. Pea Leaf Fructose 1,6-Diphosphate Aldolases.
    Plant Physiol. 1972 Mar;49(3):393-7 PMID: 16657968
Article Info
Journal
Plant physiology
Abbr.
Plant Physiol
ISSN
0032-0889
DOI
10.1104/pp.62.2.287
Published
1978-08-00
Pages
287-90
Language
English
Region
United States
NLM ID
0401224
PMCID
PMC1092107
External Links
PubMed source DOI: 10.1104/pp.62.2.287 PMC Full Text View journal details
Analysis Services
Analysis Services

Contact

No. 2 Wenbo Road, Zhangqiu District, Jinan, Shandong

Qilu Normal University · Genelibs Bioinformatics Lab

750 Shunhua Rd, Jinan

2F, Bldg F, University Science Park

Tel: 0531-88819269

WeChat Official Account

Follow our WeChat subscription account for real-time updates and the latest in medical and biological research.


Business Email

E-mail: product@genelibs.com

Copyright © 2026.Genelibs Jinan Honghui Biotechnology Co., Ltd. 鲁ICP备20007159号-2