SIDE CHAIN INTERACTIONS GOVERNING STABILITY & HELIX FORMING OF AMINO ACIDS

几个短肽（<20个残基）可以采用α-螺旋结构 在水溶液中 我们正在分析控制 这些肽的螺旋结构，包括内在的 不同氨基酸的螺旋形成趋势和特定的 稳定侧链之间的相互作用。 这些相互作用 包括特定侧链之间静电相互作用， 侧链和α-螺旋大偶极子之间，以及 非极性侧链之间的疏水相互作用。 我们的基本宿主 肽主要由丙氨酸和赖氨酸或 加入谷氨酰胺以提供水溶性。 丙氨酸宿主肽 是螺旋形的，这是因为 丙氨酸 我们在这个宿主肽中进行特定的取代， 为了研究其他残基的螺旋倾向，或 测量侧链之间的特定相互作用。 的 数据分析与经典的螺旋线圈过渡理论， 使我们能够量化单一替代品或特定替代品的影响， 相互作用对α-螺旋肽的稳定性的影响。

Several short peptide (<20 residues) can adopt a-helical structure in aqueous solution. We are analyzing the factors which control the helical structure of these peptides, including the intrinsic helix-forming tendencies of different amino acids and specific stabilizing interactions between side chains. These interactions include electrostatic interactions between specific side chains and between side chains and the a-helix macro-dipole as well as hydrophobic interactions between nonpolar side chains. Our basic host peptide is comprised primarily of alanine with either lysine or glutamine added to afford water solubility. The alanine host peptide is helical because of the high intrinsic helix forming tendency of alanine. We make specific substitutions into this host peptide in order to investigate the helix propensities of other residues, or to make measurements of specific interactions between side chains. The data are analyzed with classical helix-coil transition theory which allows us to quantitate the effects of single replacements or specific interactions on the stability of the a-helical peptide.