Investigation on the Inclusion Behavior of ApoCopC with Vitamin B₆

Abstract

In neutral phosphate buffer solution of pH 7.0, the interaction between apoCopC and Vitamin B6 has been investigated in detail by means of fluorescence spectroscopy. According to the change of Vitamin B6 fluorescence spectra and fluorescence polarization, we can conclude that a novel supramolecular system is generated. ApoCopC can form a 1:5 host-guest inclusion supramolecular complex with Vitamin B6, and the formation constant has been calculated to be (2.24 ± 0.08) × 104 M− 1. It suggests the strong inclusion ability of apoCopC to the guest molecules. In addition, the mechanism of the apoCopC protein fluorescence quenching by Vitamin B6 was also discussed. And based on the Stern-Volmer equation, the apparent quenching constant was estimated to be (2.75 ± 0.05) × 104 M− 1.