Amylose Stereoselectively Includes Poly(D-alanine) to Form Inclusion Complex in Vine-Twining Polymerization: A Novel Saccharide-Peptide Supramolecular Conjugate

摘要

In this study, it is found that amylose stereoselectively includes poly(D-alanine) in the polyalanine stereoisomers in vine-twining polymerization to form the corresponding inclusion complex, a novel saccharide-peptide supramolecular conjugate. The vine-twining polymerization is performed by thermostable phosphorylase-catalyzed enzymatic polymerization, which produces amylose, in the presence of poly(D-alanine), poly(L-alanine), or poly(DL-alanine) dispersed in aqueous buffer solvent. The X-ray diffraction and H-1 NMR measurements of the products indicate that the inclusion complex is formed from poly(D-alanine), whereas the systems using the other stereoisomers do not induce the inclusion complexation. The analytical results and the guest exchange experiment suggest the that average molecular ratio of amylose to poly(D-alanine) is 1:1, and the host cavity is partially occupied by the guest.