DISCOVERY OF A NOVEL PROTEIN MODIFICATION - ALPHA-GLYCEROPHOSPHATE ISA SUBSTITUENT OF MENINGOCOCCAL PILIN

Pili, which are filamentous protein structures on the surface of the m eningitis-causing organism Neisseria meningitidis, are known to be pos t-translationally modified with substituents that affect their mobilit y in SDS/PAGE and which might play a crucial role in adherence and blo odstream invasion. Tryptic digests of pili were analysed by fast atom bombardment and electrospray MS to identify putative modifications. Se rine-93 was found to carry a novel modification of alpha-glycerophosph ate. This is the first time that alpha-glycerophosphate has been obser ved as a substituent of a prokaryotic or eukaryotic protein.