Identification of the transferrin- and lactoferrin-binding proteins in Haemophilus influenzae.
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.
Schryvers
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AB
Department of Microbiology and Infectious Diseases, University of Calgary, Alberta, Canada.
D006193:Haemophilus influenzae / Q000032:analysis* / Q000378:metabolism; D007781:Lactoferrin / Q000378:metabolism*; D007782:Lactoglobulins / Q000378:metabolism*; D008970:Molecular Weight; D011956:Receptors, Cell Surface / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D011990:Receptors, Transferrin / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D014168:Transferrin / Q000378:metabolism*
D007782:Lactoglobulins; D011956:Receptors, Cell Surface; D011990:Receptors, Transferrin; D014168:Transferrin; C038340:lactoferrin receptors; D007781:Lactoferrin