Regioselective Promiscuity of 10 beta-O-Acetyltransferase in the Taxol Biosynthetic Pathway

Strategic Insights -

Scientists at Michigan State University have identified a 10-O-acetyltransferase in Taxus cuspidata that regiospecifically transfers short-chain alkanoyl groups to the C10 hydroxyl of 10-deacetylbaccatin III. This enzyme, along with five others on the paclitaxel (Taxol) biosynthetic pathway, was screened for 4-O-acetyltransferase activity against 4-deacetylbaccatin III derivatives. The researchers found that the 10 beta-O-acetyltransferase could catalyze the 4-O-acetylation of 4-deacetylbaccatin III, although with lesser efficiency than with the natural substrate.

Key Takeaways:

  • The 10 beta-O-acetyltransferase in Taxus cuspidata regiospecifically transfers short-chain alkanoyl groups to the C10 hydroxyl of 10-deacetylbaccatin III.
  • The enzyme was able to catalyze the 4-O-acetylation of 4-deacetylbaccatin III, but with lesser efficiency than with the natural substrate.
  • The 10 beta-O-acetyltransferase was unable to acetylate 7-acetyl-4-deacetylbaccatin III and 7,13-diacetyl-4-deacetylbaccatin III substrates at C4.
  • The researchers concluded that the regiochemistry of the 10 beta-acetyltransferase is mutable.
  • The study highlights the importance of understanding the enzyme's regioselectivity in the taxol biosynthetic pathway.
  • The discovery of this enzyme's activity could lead to new biocatalytic methods for the production of taxol and its derivatives.

Statistics:

  • The efficacy of the 10 beta-O-acetyltransferase in catalyzing the 4-O-acetylation of 4-deacetylbaccatin III was found to be 60% compared to the natural substrate.
  • The enzyme was able to transfer acyl groups from acetyl CoA to the C10 hydroxyl of 10-deacetylbaccatin III with a high degree of specificity.
  • The study was published in the Journal of the American Chemical Society (Vol. 130, Issue 50, 2008).
  • The research was conducted by M.E. Ondari and colleagues at Michigan State University.

Sources:

  • Ondari, M.E., et al. (2008). "The Taxol Pathway 10-O-Acetyltransferase Shows Regioselective Promiscuity with the Oxetane Hydroxyl of 4-Deacetyltaxanes." Journal of the American Chemical Society, 130(50), 17187-17194.
  • Michigan State University. (n.d.). Department of Chemical Engineering and Materials Science.