Application of gamma-glutamic acid polymer produced by Bacillus subtilis var natto for anti-influenza virus agents

Sialic acid-containing carbohydrates are critical determinants for influenza virus infection. To understand the host range, tissue tropism, and virulence of viruses, it is critical to elucidate the molecular mechanisms of the interaction of viral proteins with receptor molecules. We chemically synthesized gamma-glutamic acid-based glycopolymers with different length of carbohydrates and applied them for anti-influenza virus agents. Our in vitro assay demonstrated that glycopolymers potently inhibited viral infection. Elongation of core carbohydrate chains markedly increased inhibitory effect of influenza virus. Nasal administration of glycopolymers with longest carbohydrate chains protected mice against the lethal challenge of influenza virus and restrained weight loss of mice.