Design, synthesis and evaluation of β-lactam antigenic peptide hybrids; unusual opening of the β-lactam ring in acidic media
作者:Marion Tarbe、Itxaso Azcune、Eva Balentová、John J. Miles、Emily E. Edwards、Kim M. Miles、Priscilla Do、Brian M. Baker、Andrew K. Sewell、Jesus M. Aizpurua、Céline Douat-Casassus、Stéphane Quideau
DOI:10.1039/c003877f
日期:——
β-Lactam peptides were envisioned as conformational constraints in antigenic peptides (APs). Three different β-lactam tripeptides of varying flexibility were prepared in solution and incorporated in place of the central part of the altered melanoma associated antigenic peptide Leu27-Melan-A26â35 using solid phase synthesis techniques. Upon TFA cleavage from the solid support, an unexpected opening of the β-lactam ring occurred with conservation of the amide bond. After adaptation of the solid phase synthesis strategy, β-lactam peptides were successfully obtained and both opened and closed forms were evaluated for their capacity to bind to the antigen-presenting class-I MHC HLA-A2 protein system. None of the closed β-lactam peptides bound to HLA-A2, but their opened variants were shown to be moderate to good HLA-A2 ligands, one of them being even capable of stimulating a Melan-A-specific T cell line.
设想β-内酰胺肽在抗原肽(APs)中作为构象约束。通过溶液制备了三种不同灵活性的β-内酰胺三肽,并采用固相合成技术将其取代改变的黑色素瘤相关抗原肽Leu27-Melan-A26-35的中心部分。在TFA从固相支持物切割后,发生了意外的β-内酰胺环打开,同时保留了酰胺键。在固相合成策略的适应之后,成功获得了β-内酰胺肽,并且评估了它们的打开和关闭形式与抗原呈递I类MHC HLA-A2蛋白系统的结合能力。没有任何封闭的β-内酰胺肽与HLA-A2结合,但它们的打开变体显示出从中等到良好的HLA-A2配体能力,其中一个甚至能够刺激Melan-A特异性T细胞系。