: The microbiological transformaion of a natural taxoid 10-deacetylbaccatin III into its C-7 epimer, 10-deacetylbaccatin V with Microsphaeropsis onychiuri, a fungus isolated from the inner bark of Taxus yunnanensis is...: The microbiological transformaion of a natural taxoid 10-deacetylbaccatin III into its C-7 epimer, 10-deacetylbaccatin V with Microsphaeropsis onychiuri, a fungus isolated from the inner bark of Taxus yunnanensis is described.展开更多
10-DeacetylbaccatinⅢ(10-DAB)C10 acetylation is an indispensable procedure for Taxol semi-synthesis,which often requires harsh conditions.10-DeacetylbaccatinⅢ-10-β-O-acetyltransferase(DBAT)catalyzes the acetylation ...10-DeacetylbaccatinⅢ(10-DAB)C10 acetylation is an indispensable procedure for Taxol semi-synthesis,which often requires harsh conditions.10-DeacetylbaccatinⅢ-10-β-O-acetyltransferase(DBAT)catalyzes the acetylation but acetyl-CoA supply remains a key limiting factor.Here we refactored the innate biosynthetic pathway of acetyl-CoA in Escherichia coli and obtained a chassis with acetyl-CoA productivity over three times higher than that of the host cell.Then,we constructed a microbial cell factory by introducing DBAT gene into this chassis for efficiently converting 10-DAB into baccatinⅢ.We found that baccatinⅢcould be efficiently deacetylated into 10-DAB by DBAT with CoASH and K+under alkaline condition.Thus,we fed acetic acid to the engineered strain both for serving as a substrate of acetyl-CoA biosynthesis and for alleviating the deacetylation of baccatinⅢ.The fermentation conditions were optimized and the baccatinⅢtiters reached 2,3 and 4.6 g/L,respectively,in a 3-L bioreactor culture when 2,3 and 6 g/L of 10-DAB were supplied.Our study provides an environmentfriendly approach for the large scale 10-DAB acetylation without addition of acetyl-CoA in the industrial Taxol semi-synthesis.The finding of DBAT deacetylase activity may broaden its application in the structural modification of pharmaceutically important lead compounds.展开更多
文摘: The microbiological transformaion of a natural taxoid 10-deacetylbaccatin III into its C-7 epimer, 10-deacetylbaccatin V with Microsphaeropsis onychiuri, a fungus isolated from the inner bark of Taxus yunnanensis is described.
基金supported by the National Key Research and Development Program of China(grant Nos.2018YFA0901900 and 2020YFA0908003)the Drug Innovation Major Project(grant No.2018ZX09711001-006-001,China)+2 种基金the National Natural Science Foundation of China(grant No.81573325)the CAMS Innovation Fund for Medical Sciences(CIFMS,(grant No.2017-I2M-2-004,2019-I2M-1-005,China)PUMC Disciplinary Development of Synthetic Biology(201920100801,China)。
文摘10-DeacetylbaccatinⅢ(10-DAB)C10 acetylation is an indispensable procedure for Taxol semi-synthesis,which often requires harsh conditions.10-DeacetylbaccatinⅢ-10-β-O-acetyltransferase(DBAT)catalyzes the acetylation but acetyl-CoA supply remains a key limiting factor.Here we refactored the innate biosynthetic pathway of acetyl-CoA in Escherichia coli and obtained a chassis with acetyl-CoA productivity over three times higher than that of the host cell.Then,we constructed a microbial cell factory by introducing DBAT gene into this chassis for efficiently converting 10-DAB into baccatinⅢ.We found that baccatinⅢcould be efficiently deacetylated into 10-DAB by DBAT with CoASH and K+under alkaline condition.Thus,we fed acetic acid to the engineered strain both for serving as a substrate of acetyl-CoA biosynthesis and for alleviating the deacetylation of baccatinⅢ.The fermentation conditions were optimized and the baccatinⅢtiters reached 2,3 and 4.6 g/L,respectively,in a 3-L bioreactor culture when 2,3 and 6 g/L of 10-DAB were supplied.Our study provides an environmentfriendly approach for the large scale 10-DAB acetylation without addition of acetyl-CoA in the industrial Taxol semi-synthesis.The finding of DBAT deacetylase activity may broaden its application in the structural modification of pharmaceutically important lead compounds.
