RT Journal Article SR Electronic(1) A1 Lee, B CraigYR 1994 T1 Isolation and characterization of the haeminbinding proteins from Neisseria meningitidis JF Microbiology, VO 140 IS 6 SP 1473 OP 1480 DO https://doi.org/10.1099/00221287-140-6-1473 PB Microbiology Society, SN 1465-2080, AB 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., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-140-6-1473