Total Synthesis of Mycobacterium tuberculosis Dideoxymycobactin-838 and Stereoisomers: Diverse CD1a-Restricted T Cells Display a Common Hierarchy of Lipopeptide Recognition

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• 作者：Dr. Janice M. H. Cheng ; Dr. Ligong Liu ; Dr. Daniel G. Pellicci ; Scott J. J. Reddiex ; Rachel N. Cotton ; Dr. Tan-Yun Cheng ; Dr. David C. Young ; Dr. Ildiko Van Rhijn ; Prof. D. Branch Moody ; Prof. Jamie Rossjohn ; Prof. David P. Fairlie ; Prof. Dale I. Godfrey and Prof. Spencer J. Williams
• 刊名：Chemistry - A European Journal
• 出版年：2017
• 出版时间：January 31, 2017
• 年：2017
• 卷：23
• 期：7
• 页码：1694-1701
• 全文大小：1247K
• ISSN：1521-3765

文摘

Mycobacterium tuberculosis produces dideoxymycobactin-838 (DDM-838), a lipopeptide that potently activates T cells upon binding to the MHC-like antigen-presenting molecule CD1a. M. tuberculosis produces DDM-838 in only trace amounts and a previous solid-phase synthesis provided sub-milligram quantities. We describe a high-yielding solution-phase synthesis of DDM-838 that features a Mitsunobu substitution that avoids yield-limiting epimerization at lysine during esterification, and amidation conditions that prevent double-bond isomerization of the Z-C20:1 acyl chain, and provides material with equivalent antigenicity to natural DDM-838. Isomers of DDM-838 that varied in stereochemistry at the central lysine and the C20:1 acyl chain were compared for their ability to be recognised by CD1a-restricted T cell receptors (TCRs). These TCRs, derived from unrelated human donors, exhibited a similar spectrum of reactivity towards the panel of DDM-838 isomers, highlighting the exquisite sensitivity of lipopeptide-reactive T cells for the natural DDM stereochemistry.