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Enzymatic C‐4 deacetylation of 10‐deacetylbaccatin III
Author(s) -
Hanson Ronald L.,
Parker William L.,
Patel Ramesh N.
Publication year - 2006
Publication title -
biotechnology and applied biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 70
eISSN - 1470-8744
pISSN - 0885-4513
DOI - 10.1042/ba20060073
Subject(s) - enzyme , chemistry , acetylation , paclitaxel , yield (engineering) , biochemistry , stereochemistry , chromatography , biology , cancer , genetics , materials science , metallurgy , gene
Second‐generation paclitaxel analogues that require replacement of the C‐4 acetate by other substituents are in development. An enzyme able to specifically remove the C‐4 acetate from paclitaxel could simplify preparation of the analogues. Several strains were isolated from soil samples that contain enzyme activities able to 4‐deacetylate 10‐DAB (10‐deacetylbaccatin III). Selection was made using plates containing 10‐DAB as the sole carbon source and screening colonies for deacetylation of 10‐DAB. Two strains initially isolated were identified as Rhodococcus sp. and deposited with the A.T.C.C. (Manassas, VA, U.S.A.) as strains 202191 and 202192. Whole cells were able to convert 10‐DAB into 4,10‐DDAB (4‐deacetyl‐10‐deacetylbaccatin III) in 90% yield. The enzyme activity in these strains was not effective with paclitaxel and 10‐deacetylpaclitaxel, although 4,10‐DDAB was produced from baccatin III. The activity in these strains was associated with an insoluble fraction of cell extracts. Several additional isolates were obtained that were identified as variants of Stenotrophomonas maltophilia , and a soluble C‐4 deacetylase was purified approx. 218‐fold from one of them. The activity of this enzyme was limited to 10‐DAB, and the enzyme was not effective with paclitaxel or baccatin III.