Study on mechanism of electronic states of Interferon alpha2

Abstract

Interferon (IFN) α2 is a 165-residue protein, and there is a recombinant IFN α2b that differs from the wild strain (IFN α2a) only at the 23rd residue of the amino acid sequence (Lys23Arg). IFN α2a can bind to the interferon receptor (IFNAR2). The 23rd amino acid is not in direct contact with IFNAR2, but IFN α2b is known to be more active than IFN α2a. In this study, in order to investigate the cause of difference, we performed canonical molecular orbital calculations and examined the difference in electronic states associated with the mutation. The results of electrostatic potential and Milliken charges suggest that the difference of Lys23Arg may produce a gain in the Coulomb force.