Total Synthesis of<i>Mycobacterium tuberculosis</i>Dideoxymycobactin-838 and Stereoisomers: Diverse CD1a-Restricted T Cells Display a Common Hierarchy of Lipopeptide Recognition
作者:Janice M. H. Cheng、Ligong Liu、Daniel G. Pellicci、Scott J. J. Reddiex、Rachel N. Cotton、Tan-Yun Cheng、David C. Young、Ildiko Van Rhijn、D. Branch Moody、Jamie Rossjohn、David P. Fairlie、Dale I. Godfrey、Spencer J. Williams
DOI:10.1002/chem.201605287
日期:2017.1.31
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
结核分枝杆菌产生双脱氧分枝杆菌素838(DDM-838),这是一种脂肽,与MHC样抗原呈递分子CD1a结合后可有效激活T细胞。结核分枝杆菌仅产生痕量的DDM-838,而以前的固相合成提供了亚毫克级的量。我们描述了一种高产的DDM-838固溶体合成,其特征在于进行了Mitsunobu取代,避免了酯化过程中赖氨酸的产量限制差向异构化,以及防止Z发生双键异构化的酰胺化条件‐C20:1酰基链,可提供与天然DDM-838具有相同抗原性的物质。比较了DDM-838异构体在中央赖氨酸和C20:1酰基链上的立体化学变化,以识别其被CD1a限制性T细胞受体(TCR)识别的能力。这些源自不相关人类供体的TCR对DDM-838异构体的反应显示出相似的光谱,突显了脂肽反应性T细胞对天然DDM立体化学的精妙敏感性。