%0 Journal Article %A Lee, B Craig %T Isolation and characterization of the haeminbinding proteins from Neisseria meningitidis %D 1994 %J Microbiology, %V 140 %N 6 %P 1473-1480 %@ 1465-2080 %R https://doi.org/10.1099/00221287-140-6-1473 %K Neisseria meningitidis %K meningococcal disease %K haemoglobin %K iron %K haemin-binding proteins %I Microbiology Society, %X The mechanism of haem-iron acquisition in Neisseria meningitidis is poorly understood. Using haemin-agarose in a batch affinity chromatography method, two haemin-binding proteins of 97 and 50 kDa were isolated from total membranes derived from Neisseria meningitidis B16B6 grown under iron-deficient but not under iron-replete conditions. No binding proteins were affinity-purified when total membranes underwent limited proteolysis with trypsin, suggesting a haem-protein interaction. When biotinylated human haemoglobin was used as the affinity ligand, proteins of identical molecular mass were isolated. Detection of haemin-binding proteins in a whole cell binding assay demonstrated a surface-exposed location. Competitive binding studies indicated that this haem-protein interaction was specific, because only haemin or human haemoglobin, but not cytochrome c111' protoporphyrin IX, iron-loaded human lactoferrin, iron-loaded human transferrin or Fe(NO3)3, could abrogate binding. The presence of similar haemin-binding proteins in a limited survey of clinical meningococcal strains indicated that the expression of the haemin-binding proteins is not serogroup-specific. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-140-6-1473