Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, Michigan 48202, USA.
J Am Chem Soc. 2010 Feb 10;132(5):1567-71. doi: 10.1021/ja906611x.
Several peptides/small proteins and glycosylphosphatidylinositol (GPI) derivatives were synthesized and compared as substrates of sortase A (SrtA), a bacterial transpeptidase, for enzymatic coupling. It was observed that peptides containing the LPKTGGS and LPKTGGRS sequences as sorting signals at the peptide C-terminus were effectively coupled to GPI derivatives having one or two glycine residues attached to the phosphoethanolamine group at the nonreducing end. This reaction was employed to prepare several analogues of the human CD52 and CD24 antigens, which are naturally GPI-anchored glycopeptides/glycoproteins. It was further observed that the trisaccharide GPI analogues 5 and 6 were better SrtA substrates than monosaccharide GPI analogue 4, suggesting that steric hindrance of the GPI analogues does not affect their peptidation reaction mediated by SrtA. Therefore, this synthetic strategy may be useful for the preparation of more complex GPI-anchored peptides, glycopeptides, proteins, and glycoproteins.
几种肽/小蛋白和糖基磷脂酰肌醇（GPI）衍生物被合成并比较，作为细菌转肽酶 SrtA 的酶偶联底物。结果表明，在肽 C 末端含有 LPKTGGS 和 LPKTGGRS 序列作为分选信号的肽能够有效地与一个或两个甘氨酸残基连接到非还原末端磷酸乙醇胺基团的 GPI 衍生物偶联。该反应用于制备几种人 CD52 和 CD24 抗原的类似物，这些抗原是天然 GPI 锚定的糖肽/糖蛋白。进一步观察到，三糖 GPI 类似物 5 和 6 比单糖 GPI 类似物 4 更适合 SrtA 作为底物，这表明 GPI 类似物的空间位阻不会影响它们由 SrtA 介导的肽化反应。因此，这种合成策略可能对制备更复杂的 GPI 锚定肽、糖肽、蛋白质和糖蛋白有用。
