Muñoz V, Blanco F J, Serrano L
EMBL, Heidelberg, Germany.
Nat Struct Biol. 1995 May;2(5):380-5. doi: 10.1038/nsb0595-380.
A recurrent local structural motif is described at the amino terminus of alpha-helices, that consists of a specific hydrophobic interaction between a residue located before the N-cap, with a residue within the helix (i,i+5 interaction). NMR and CD analysis of designed peptides demonstrate its presence in aqueous solution, its contribution to alpha-helix stability and its role in defining the alpha-helix N terminus limit. Comparison between the N-terminal structures of the peptide and those in proteins with the same fingerprint sequence, shows striking similarities. The change in the polypeptide chain direction produced by the motif suggests an important role in protein folding for residues located in polypeptide segments between secondary structure elements.
在α-螺旋的氨基末端描述了一种反复出现的局部结构基序，它由位于N-帽之前的一个残基与螺旋内的一个残基之间的特定疏水相互作用组成（i，i + 5相互作用）。对设计肽的核磁共振（NMR）和圆二色性（CD）分析表明其存在于水溶液中，对α-螺旋稳定性有贡献，并在定义α-螺旋N末端界限中起作用。该肽的N末端结构与具有相同指纹序列的蛋白质中的N末端结构之间的比较显示出惊人的相似性。该基序产生的多肽链方向变化表明，位于二级结构元件之间的多肽片段中的残基在蛋白质折叠中起重要作用。
