Applied Microbiology and Biotechnology

, Volume 56, Issue 1, pp 131–136

Comparative study of the relationship between monomer structure and reactivity for two polyhydroxyalkanoate synthases

  •  S. Zhang
  •  M. Kamachi
  •  Y. Takagi
  •  R. Lenz
  •  S. Goodwin
Original Paper

DOI: 10.1007/s002530000562

Cite this article as:
Zhang, S., Kamachi, M., Takagi, Y. et al. Appl Microbiol Biotechnol (2001) 56: 131. doi:10.1007/s002530000562

Abstract.

Using organically synthesized hydroxyalkanoate coenzyme A thioesters, the activities of two short-chain polyhydroxalkanoate (PHA) synthases were investigated – Ralstonia eutropha PHA synthase (a type I PHA synthase) and Ectothiorhodospira shaposhnikovii PHA synthase (a type III synthase). The results indicate that the two synthases have similar activities towards most of the monomers tested. 3-Hydroxybutyryl CoA was found to be the most efficient substrate for both synthases. Changes in the side-chain length of the monomers affect monomer reactivity, with shortening of the side-chain length having the more severe effect. Hydrophobicity in the side chain appears to play an important role in the catalytic reaction. The configuration and the position of the hydroxyl group also affect the reactivity of a monomer. Monomers with the [S] configuration can not be recognized by either synthase. Moving the hydroxyl group from the β carbon to the α carbon has a much more severe effect on the reactivity of the monomer than moving the hydroxyl group to the γ carbon. The results demonstrate that the in vitro system can be used to prepare entirely novel polymers that may not be obtainable from living cells because of metabolic restrictions.

Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  •  S. Zhang
    • 1
  •  M. Kamachi
    • 2
  •  Y. Takagi
    • 2
  •  R. Lenz
    • 2
  •  S. Goodwin
    • 1
  1. 1.Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
  2. 2.Polymer Science and Engineering Department, University of Massachusetts, Amherst, MA 01003, USA
  3. 3.Present address: Nagoya Municipal Industrial Research Institute, Japan