Chirality sensing of various biomolecules with helical poly(phenylacetylene)s bearing acidic functional groups in water

Stereoregular, cis-transoidal poly(phenylacetylene)s bearing strongly acidic functional groups as pendants, such as a phosphonic acid and its monoethyl. ester and a sulfonic acid, were found to interact with various biomolecules such as peptides, proteins, amino sugars, and carbohydrates in water, and the complexes exhibited characteristic induced circular dichroisms in the ultraviolet-visible region of the polymer backbones, which resulted from the formation of predominantly one-handed helical conformations. On the other hand, the sodium salt of poly[(4-carboxyphenyl)acetylenel, bearing a weak acidic carboxy group, showed induced circular dichroisms only in the presence of carbohydrates and some positively charged proteins. The sensitivity of the polymers to the chirality of various biomolecules was also investigated with circular dichroism spectroscopy. (c) 2006 Wiley Periodicals, Inc.