BOTH THE FULL-LENGTH AND THE N-TERMINAL DOMAIN OF THE MENINGOCOCCAL TRANSFERRIN-BINDING PROTEIN-B DISCRIMINATE BETWEEN HUMAN IRON-LOADED AND APO-TRANSFERRIN

We have readdressed the ability of the transferrin-binding protein B ( TbpB) from Neisseria meningitidis to discriminate between the iron-loa ded and the iron-free human transferrin (hTf) by using the BIAcore tec hnology, a powerful experimental technique for the observation of dire ct interactions between a receptor and its ligands, without the use of labels. Recombinant full-length TbpB from five N. meningitidis strain s were produced and purified from Escherichia coli as fusion proteins. They showed a preference for the binding to iron-loaded hTf. As for t he full-length molecule, we have demonstrated that the minimal N-termi nal hTf binding domain of meningococcal TbpB from B16B6 and M982 strai ns was able to discriminate between both hTf forms. (C) 1998 Federatio n of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.