Molecular Recognition of Bridged Bis(beta-cyclodextrin) Linked by the 4,4'-Diaminodiphenyl Sulfone Tether with Non-aromatic Oligopeptides

作者：Zhao Yan; Yang Yong Cun; Shi Hao; Zhao Yong; Chi Shao Ming; Zhu Hong You; Huang Rong

来源：Journal of Solution Chemistry, 2010, 39(7): 987-998.

DOI：10.1007/s10953-010-9564-3

• Bridged bis(beta-cyclodextrin)s
• Non-aromatic oligopeptides
• Fluorescence spectroscopy
• Molecular recognition
• Inclusion phenomena

The molecular recognition behavior of 4,4'-diaminodiphenyl sulfone bis(beta-cyclodextrin) 1 with representative non-aromatic oligopeptides (Leu-Gly, Gly-Leu, Glu-Glu, Met-Met, Gly-Gly, Gly-Gly-Gly and Gly-Pro) was investigated by circular dichroism, fluorescence, (1)H and 2D NMR spectroscopy at 25 A degrees C in phosphate buffer solutions (pH=7.20). From the circular dichroism and 2D NMR results, it is inferred that the phenyl moiety in the linker of bis(beta-cyclodextrin) is partly self-included in the cyclodextrin cavity, and it is entirely expelled out of the cyclodextrin cavity upon complexation with oligopeptides. Owing to the cooperative sandwich binding mode, bis(beta-cyclodextrin) not only affords the highest binding constant of 29200 La <...mol(-1) for the tripeptide Gly-Gly-Gly, but it also can recognize the size and hydrophobicity of oligopeptides. The bis(beta-cyclodextrin) gives an exciting residue selectivity of up to 78.9 for the Gly-Gly-Gly/Glu-Glu pair, and a higher length selectivity of up to 28.1 for the Gly-Gly-Gly/Gly-Gly pair. These phenomena are discussed from the viewpoint of the size-fit concept and multipoint recognition between host and guest.

• 出版日期2010-7
• 单位云南师范大学; 云南大学