Construction of acetyl-CoA and DBAT hybrid metabolic pathway for acetylation of 10-deacetylbaccatin Ⅲ to baccatin Ⅲ

• 作者: Hao Wang Bo-Yong Zhang Ting Gong Tian-Jiao Chen Jing-Jing Chen Jin-Ling Yang Ping Zhu
• 来源期刊: 药学学报（英文版）
• 年，卷（期）: 2021,（10）
• 所属期刊栏目: Original articles
• 页码范围: 3322-3334
• 页数: 13页
• 语种: 英文

摘要

10-Deacetylbaccatin Ⅲ (10-DAB) C10 acetylation is an indispensable procedure for Taxol semi-synthesis,which often requires harsh conditions.10-Deacetylbaccatin Ⅲ-10-β-O-acetyltransferase(DBAT) catalyzes the acetylation but acetyl-CoA supply remains a key limiting factor.Here we refac-tored 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 micro-bial cell factory by introducing DBAT gene into this chassis for efficiently converting 10-DAB into bac-catin Ⅲ.We found that baccatin Ⅲ could 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 baccatin Ⅲ.The fermenta-tion conditions were optimized and the baccatin Ⅲ titers 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 environment-friendly 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 struc-tural modification of pharmaceutically important lead compounds.