Structural Dimorphism of Achiral α,γ‐Hybrid Peptide Foldamers: Coexistence of 12‐ and 15/17‐Helices
作者:Rajkumar Misra、Abhijith Saseendran、Gijo George、Kuruva Veeresh、K. Muruga Poopathi Raja、Srinivasarao Raghothama、Hans‐Jörg Hofmann、Hosahudya N. Gopi
DOI:10.1002/chem.201605753
日期:2017.3.13
of continuously lengthened Aib/Aic‐hybrid peptides confirm that the 12‐helix is more stable than the 15/17‐helix in shorter peptides, whereas the 15/17‐helix is more stable in longer sequences. Thus, the coexistence of both helix types can be expected within a definite range of sequence lengths. The novel 15/17‐ and 12‐helices in α,γ‐hybrid peptides with 5→1 and 4→1 hydrogen‐bonding patterns, respectively
在这里,报道了由非手性α-氨基异丁酸(Aib)和4-氨基异己酸(Aic,双重同源的Aib)单体以1:1交替组成的α,γ-杂合肽中的新型12螺旋。通过对四肽和七肽的溶液和晶体结构分析表明了12个螺旋。出乎意料的是,更长的九肽单晶显示出两种不同的螺旋类型:新颖的12螺旋和前所未有的15/17螺旋。一系列连续加长的Aib / Aic杂合肽中两种螺旋类型的量子化学计算证实,短肽中12螺旋比15/17螺旋更稳定,而15/17螺旋在短肽中更稳定较长的序列。因此,可以在一定的序列长度范围内预期两种螺旋类型的共存。α中的新颖15/17和12螺旋10个螺旋。