Capasso S, Mazzarella L, Zagari A
Centro di Studio di Biocristallografia, CNR, Facoltà di Scienze Ambientali, Seconda Università degli Studi di Napoli, Italy.
Chirality. 1995;7(8):605-9. doi: 10.1002/chir.530070808.
The conformational equilibrium of aminosuccinyl peptides between extended conformations and an intramolecularly hydrogen bonded type II' beta-turn conformation has been studied on the peptide Boc-L-Asu-Gly-L-Ala-OMe (Asu = aminosuccinyl residue) by means of temperature dependence of circular dichroism spectra. Owing to the peculiar chiroptical and conformational properties of the Asu residue, this technique proved to be very useful for deriving thermodynamic data for the above folding process. The value of delta H0 (-6.6 kJ mol-1), obtained for the peptide studied in a chloroformacetonitrile mixture, shows that the lower energy of the folded conformer is primarily due to the characteristic intramolecular hydrogen bond of the beta turns.
通过圆二色光谱的温度依赖性，对肽Boc-L-天冬氨酰-甘氨酸-L-丙氨酸-甲酯（天冬氨酰=氨基琥珀酰残基）在伸展构象和分子内氢键结合的II'型β-转角构象之间的构象平衡进行了研究。由于天冬氨酰残基独特的手性光学和构象性质，该技术被证明对于推导上述折叠过程的热力学数据非常有用。在氯仿 - 乙腈混合物中研究的该肽所获得的ΔH0值（-6.6 kJ mol-1）表明，折叠构象体较低的能量主要归因于β-转角的特征性分子内氢键。
