Ram S, Ngampasutadol J, Cox AD, Blom AM, Lewis LA, St Michael F, Stupak J, Gulati S, Rice PA. Heptose I glycan substitutions on Neisseria gonorrhoeae lipooligosaccharide influence C4b-binding protein binding and serum resistance. Infect Immun. 2007 Aug; 75(8):4071-81.