Basu G, Kuki A
Cornell University, Department of Chemistry, Baker Laboratory, Ithaca, New York 14853.
Biopolymers. 1992 Jan;32(1):61-71. doi: 10.1002/bip.360320109.
The analysis of the factors that control the helical folding of Aib-rich peptides is extended to include sensitivity to sequence patterns, and in particular the presence of contiguous non-Aib alpha-mono-alkylated residues. The distinct hydrogen-bonding network of the 3(10)-helix, as contrasted with that of the competing alpha-helical structure, is explicitly incorporated into a theoretical model for the 3(10)-helix/alpha-helix equilibrium constant for a given peptide. Finite length effects and the "extra" intrahelical hydrogen bond of the 3(10) form are expressed naturally as a result of this loop analysis. This semiempirical model captures all the established features of existing empirical rules for helical conformational transitions in Aib-rich sequences, as well as the recently detected helical transition induced solely by sequence permutation.
对控制富含Aib肽段螺旋折叠的因素分析进行了扩展，以包括对序列模式的敏感性，特别是连续非Aibα-单烷基化残基的存在。与竞争的α-螺旋结构不同，3(10)-螺旋独特的氢键网络被明确纳入给定肽段的3(10)-螺旋/α-螺旋平衡常数的理论模型中。有限长度效应和3(10)形式的“额外”螺旋内氢键通过这种环分析自然地体现出来。这个半经验模型捕捉了富含Aib序列中螺旋构象转变现有经验规则的所有既定特征，以及最近仅由序列排列诱导的螺旋转变。
