AknK Is an L-2-Deoxyfucosyltransferase in the Biosynthesis of the Anthracycline Aclacinomycin A

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• 作者：Wei Lu ; Catherine Leimkuhler ; Markus Oberthü ; r ; Daniel Kahne ; and Christopher T. Walsh
• 刊名：Biochemistry
• 出版年：2004
• 出版时间：April 20, 2004
• 年：2004
• 卷：43
• 期：15
• 页码：4548 - 4558
• 全文大小：169K
• 年卷期：v.43,no.15(April 20, 2004)
• ISSN：1520-4995

文摘

The antitumor drug aclacinomycin A is a representative member of the anthracycline subgroupthat contains a C₇-O-trisaccharide chain composed of L-2-deoxysugars. The sugar portion of the molecule,which greatly affects its biological activity, is assembled by dedicated glycosyltransferases; however,these enzymes have not been well-studied. Here we report the heterologous expression and purificationof one of these enzymes, AknK, as well as the preparation of dTDP-L-2-deoxysugar donors, dTDP-L-2-deoxyfucose and dTDP-L-daunosamine, and the monoglycosyl aglycone, rhodosaminyl aklavinone. Ourexperiments show that AknK catalyzes the addition of the second sugar to the chain, using dTDP-L-2-deoxyfucose and rhodosaminyl aklavinone, to create the L-2-deoxyfucosyl-L-rhodosaminyl aklavinone.AknK also accepts an alternate dTDP-L-sugar, dTDP-L-daunosamine, and other monoglycosylatedanthracyclines, including daunomycin, adriamycin, and idarubicin, to build alternate disaccharides onvariant anthracycline backbones. Remarkably, AknK also catalyzes a tandem addition of a second L-2-deoxyfucosyl moiety, albeit with reduced activity, to the natural disaccharide chain to produceL-deoxyfucosyl-L-deoxyfucosyl-L-rhodosaminyl aklavinone, a variant of the natural aclacinomycin A. Theseresults demonstrate that AknK may be a useful enzyme for the chemoenzymatic synthesis of anthracyclinevariants.