Identification of the transferrin- and lactoferrin-binding proteins in Haemophilus influenzae Schryvers, A. B.,, 29, 121-130 (1989), doi = https://doi.org/10.1099/00222615-29-2-121, publicationName = Microbiology Society, issn = 0022-2615, abstract= Surmmary An affinity procedure with purified, biotinylated human transferrin and streptavidin-agarose was used to identify the transferrin-binding proteins in strains of Haemophilus influenzae. Proteins of 58 and 98 Kda were isolated from total membranes prepared from iron-deficient but not iron-sufficient H. influenzae KC548 cells. The 58-Kda protein was capable of binding human transferrin after sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis (PAGE) and electroblotting. Isolation of transferrin-binding proteins from type-b and non-typable H. influenzae strains demonstrated some variability in the size of the higher mol. wt protein (94–106 Kda) and in ease of elution of the smaller protein from the affinity resin. Use of purified, biotinylated human lactoferrin in the affinity isolation procedure with membranes from a strain expressing lactoferrin-binding activity resulted in isolation of proteins of 105 and 106 Kda distinct from the transferrin-binding proteins., language=, type=