A Potential Role for the Major Iron-Regulated Protein Expressed by Pathogenic Neisseria Species

Several iron-regulated proteins of Neisseria gonorrhoeae and Neisseria meningitidis have been reported. One of these, a 37,000-dalton protein is the major iron-regulated protein (MIRP) and appears to be common among all gonococcal and meningococcal isolates. This protein was purified from both N. gonorrhoeae and N. meningitidis and was found to contain approximately 1 mole of Fe /mole of protein. Sera from patients with gonococcal infections contained antibodies to the MIRP. Thus, the MIRP is expressed in vivo. The iron-binding nature of the MIRP suggests that it may have a role in iron acquisition by the pathogenic Neisseria species and, therefore, may have a function in their pathogenicity.