【摘要】 β-发夹是天然蛋白质中丰富的二级结构单元之一,在蛋白折叠和功能方面扮演着重要角色.文章报导了二条多肽序列（LTVd-PGLTV,n7和LTVGDDTV,n5）的设计、合成和园二色谱研究结果.结果显示,n5在 198nm附近呈现负峰,表现为非规整结构特征;相反,n7表现为典型的发夹结构特征,在218nm附近呈负峰,196nm附近呈正峰,为β-转角与β-折叠的共同贡献.初步研究表明,β-转角、序列关系和氨基酸形成在折叠结构倾向性是β-发夹结构形成和稳定的决定性因素.更多还原

【Abstract】 β-hairpins are popular secondary structural elements in native protein and play important roles either in protein folds or functionalization. Here we describe the design and preliminary structural studies of two peptide sequences LTVd-PGLTV(n7) and LTVGDDTV(n5) synthesized by solid phase peptide synthetic strategy. The circular dichroism (CD)spectra of n5 show a negative minimum near 198 nm, random coil characteristics. On the contrary, the CD spectra of n7 show a minimum at about 218 nm and a maximum at about 196 nm, a typical β-hairpin characteristics, which have been concluded as the common contribution of a β-turn mixed with β-sheets. The results show that β-turn, sequence context and β-sheet forming tendency are determinant of β-hairpin formation and stability.更多还原