Reconstitution of the Isobutene-Forming Reaction Catalyzed by Cytochrome P450 and P450 Reductase From Rhodotorula Minuta: Decarboxylation With the Formation of Isobutene

Biochem Biophys Res Commun. 1994 Jun 15;201(2):516-22. doi: 10.1006/bbrc.1994.1732.


An isobutene-forming activity was reconstituted with cytochrome P450rm and cytochrome P450 reductase purified from Rhodotorula minuta. The nonionic detergent. Emulgen 911, present in the preparation of purified P450rm, inhibited the reconstitution. Bovine serum albumin enhanced the activity of the reconstituted system. Branching of the beta carbon of the substrate carboxylic acid was important for formation of isobutene. In a comparative study with isovalerate and 3-deuterio-3-methylbutanoate, a very large isotopic effect (kH/kD = 14) was observed. This result indicates that formation of isobutene might be initiated by abstraction of hydrogen from the beta carbon of isovalerate and might be followed by decarboxylation.

Publication types

  • Comparative Study

MeSH terms

  • Alkenes / metabolism*
  • Cytochrome P-450 Enzyme System / isolation & purification
  • Cytochrome P-450 Enzyme System / metabolism*
  • Deuterium
  • Kinetics
  • NADPH-Ferrihemoprotein Reductase / isolation & purification
  • NADPH-Ferrihemoprotein Reductase / metabolism*
  • Rhodotorula / enzymology*
  • Substrate Specificity


  • Alkenes
  • Cytochrome P-450 Enzyme System
  • Deuterium
  • NADPH-Ferrihemoprotein Reductase
  • isobutylene