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. 1988 Dec;88(4):1425–1429. doi: 10.1104/pp.88.4.1425

Synthesis and Biological Activity of an Azido Derivative of Paclobutrazol, an Inhibitor of Gibberellin Biosynthesis 1

David L Hallahan 1,2,3,2, Anthony P Heasman 1,2,3, Martin C Grossel 1,2,3, Robert Quigley 1,2,3, Peter Hedden 1,2,3, John R Bowyer 1,2,3
PMCID: PMC1055775  PMID: 16666477

Abstract

A photolabile azido derivative of the kaurene oxidase inhibitor 1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-l-yl) pentan-3-ol (paclobutrazol) has been synthesized for use as a photoaffinity labeling agent. The compound was tested as an inhibitor of the oxidation of ent-kaurene catalyzed by cell-free preparations from endosperm of Cucurbita maxima. The I50 of the azido derivative was 9.5 nanomolar, which compares well with that of paclobutrazol (6.3 nanomolar in our measurements). The azido compound bound to Cytochrome P-450 in microsomes from Cucurbita maxima, and induced a Type II spectral change, with an apparent binding constant of 0.24±0.04 micromolar.

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Selected References

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

  1. Coolbaugh R. C., Hirano S. S., West C. A. Studies on the Specificity and Site of Action of alpha-Cyclopropyl-alpha-[p-methoxyphenyl]-5-pyrimidine Methyl Alcohol (Ancymidol), a Plant Growth Regulator. Plant Physiol. 1978 Oct;62(4):571–576. doi: 10.1104/pp.62.4.571. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Coolbaugh R. C., Swanson D. I., West C. A. Comparative Effects of Ancymidol and Its Analogs on Growth of Peas and Ent-Kaurene Oxidation in Cell-Free Extracts of Immature Marah macrocarpus Endosperm. Plant Physiol. 1982 Mar;69(3):707–711. doi: 10.1104/pp.69.3.707. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Dennis D. T., West C. A. Biosynthesis of gibberellins. 3. The conversion of (-)-kaurene to (-)-kauren-19-oic acid in endosperm of Echinocystis macrocarpa Greene. J Biol Chem. 1967 Jul 25;242(14):3293–3300. [PubMed] [Google Scholar]
  4. Hasson E. P., West C. A. Properties of the System for the Mixed Function Oxidation of Kaurene and Kaurene Derivatives in Microsomes of the Immature Seed of Marah macrocarpus: Electron Transfer Components. Plant Physiol. 1976 Oct;58(4):479–484. doi: 10.1104/pp.58.4.479. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Jefcoate C. R. Measurement of substrate and inhibitor binding to microsomal cytochrome P-450 by optical-difference spectroscopy. Methods Enzymol. 1978;52:258–279. doi: 10.1016/s0076-6879(78)52029-6. [DOI] [PubMed] [Google Scholar]
  6. Markwell M. A., Haas S. M., Bieber L. L., Tolbert N. E. A modification of the Lowry procedure to simplify protein determination in membrane and lipoprotein samples. Anal Biochem. 1978 Jun 15;87(1):206–210. doi: 10.1016/0003-2697(78)90586-9. [DOI] [PubMed] [Google Scholar]
  7. Murphy P. J., West C. A. The role of mixed function oxidases in kaurene metabolism in Echinocystis macrocarpa Greene endosperm. Arch Biochem Biophys. 1969 Sep;133(2):395–407. doi: 10.1016/0003-9861(69)90468-8. [DOI] [PubMed] [Google Scholar]
  8. Swanson R. A., Dus K. M. Specific covalent labeling of cytochrome P-450CAM with 1-(4-azidophenyl)imidazole, an inhibitor-derived photoaffinity probe for P-450 heme proteins. J Biol Chem. 1979 Aug 10;254(15):7238–7246. [PubMed] [Google Scholar]

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