ヒドリンダセン型分子レセプターによって明らかになったアミド基の水素結合に伴うアロステリック効果の発現

抄録

The cooperativity in amide hydrogen-bonds plays an important role in stabilizing folded structures of protein and realizing allosterism in nature. We prepared hydrindacene-based exoditopic receptors with two amide groups as a cooperative binding site. These exoditopic receptor exhibit a positive homotropic allosteric binding process toward benzenediols and forms 1 : 2 complexes with resorcinols, and catechol with K₂/K₁=3-33. Both of the entropy and the enthalpy terms are operating in this allosteric system; the crystallographic studies provide the first clear evidence that the cooperativity in amide hydrogen bonding by polarization leads to the positive homotropic allosteric binding property. Furthermore, 1 : 1 complexation of the receptor with a dopamine salt as an allosteric effector significantly inhibits the binding with resorcinols. In the present system, we revealed that the allosteric modulation by the effector molecule leads to the cooperative release of the bound guests.