Characterization of Vaccine X
Organism X causes disease that is responsible for substantial death and morbidity throughout the world. Invasion of the bloodstream by Organism X leads to sepsis and rapid death, along with infection of other tissues, and organ systems throughout the body. Vaccine X is an innovative bivalent vaccine composed of two outer membrane lipoproteins (subfamilies A & B) from Organism X. The amino acid sequence of these proteins is known, however the 3D conformation of these proteins is yet to be elucidated. The lipidated N-terminal cysteine of the subfamily B protein was focused on and a method was developed for sequential delipidation of the N-terminus and subsequent lipid quantization. The N-terminal cysteine contains three fatty acids: palmitic acid, vaccenic acid, and palmitoleic acid. The O-linked fatty acids in the cysteine are mild base labile, and the fatty acid linked via a peptide bond can be released with high concentrations of base. Research will serve to elucidate the structure of the N-terminal cysteine acyl groups, establish potential stability indicating assays, and create an orthogonal approach for explaining anomalous results in other assays.