Skip to main content
PMC home page
Plant Physiology logoLink to Plant Physiology
. 1981 Jan;67(1):156–162. doi: 10.1104/pp.67.1.156

Purification and Properties of a Protein Which Binds Cytokinin-active 6-Substituted Purines 1

Jack L Erion 1,2,2, J Eugene Fox 1,2,3
PMCID: PMC425641  PMID: 16661618

Abstract

A protein which binds 6-substituted purines of the cytokinin type with relatively high affinity has been extensively purified from wheat germ. Conventional chromatographic techniques, as well as an affinity matrix to which a cytokinin was covalently coupled, were used in the purification. The wheat germ cytokinin-binding protein (CBF-1) has four unlike subunits and an apparent molecular weight of 183,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

CBF-1 is saturated at one cytokinin molecule per tetramer with a Kd for 6-benzylaminopurine of 5 × 10−7 molar. The protein exists both on the native wheat germ ribosome (1 molecule CBF-1 per 80S ribosome) and free in the cytosol with approximately three copies of the latter for each of the former. Data from affinity chromatography studies and cross-linking experiments strongly suggest that a specific binding site for CBF-1 occurs on the wheat germ ribosome.

Full text

PDF
156

Images in this article

159Image
on p.159

Selected References

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

  1. Benne R., Luedi M., Hershey J. W. Purification and characterization of initiation factors IF-E4 and IF-E6 from rabbit reticulocytes. J Biol Chem. 1977 Aug 25;252(16):5798–5803. [PubMed] [Google Scholar]
  2. Berridge M. V., Ralph R. K., Letham D. S. The binding of kinetin to plant ribosomes. Biochem J. 1970 Aug;119(1):75–84. doi: 10.1042/bj1190075. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Fox J. E., Erion J. L. A cytokinin binding protein from higher plant ribosomes. Biochem Biophys Res Commun. 1975 May 19;64(2):694–700. doi: 10.1016/0006-291x(75)90376-9. [DOI] [PubMed] [Google Scholar]
  4. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  5. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  6. Lamed R., Levin Y., Wilchek M. Covalent coupling of nucleotides to agarose for affinity chromatography. Biochim Biophys Acta. 1973 Apr 28;304(2):231–235. doi: 10.1016/0304-4165(73)90239-0. [DOI] [PubMed] [Google Scholar]
  7. LeJohn H. B., Cameron L. E. Cytokinins regulate calcium binding to a glycoprotein from fungal cells. Biochem Biophys Res Commun. 1973 Oct 1;54(3):1053–1060. doi: 10.1016/0006-291x(73)90800-0. [DOI] [PubMed] [Google Scholar]
  8. Moore F. H. A Cytokinin-binding Protein from Wheat Germ: Isolation by Affinity Chromatography and Properties. Plant Physiol. 1979 Oct;64(4):594–599. doi: 10.1104/pp.64.4.594. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Polya G. M., Bowman J. A. Ligand Specificity of a High Affinity Cytokinin-binding Protein. Plant Physiol. 1979 Sep;64(3):387–392. doi: 10.1104/pp.64.3.387. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Yoshida K., Takegami T. Isolation of cytokinin binding protein from tobacco leaves by bioaffinity chromatography and its partial characterization. J Biochem. 1977 Mar;81(3):791–799. doi: 10.1093/oxfordjournals.jbchem.a131517. [DOI] [PubMed] [Google Scholar]

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

RESOURCES