title: The region of human transferrin involved in binding to bacterial transferrin receptors is localized in the C-lobe.
abstract: Iron-saturated human transferrin was digested with either chymotrypsin or trypsin to produce C-lobe and N-lobe protein fragments. Individual protein fragments were purified by a combination of gel filtration and Concanavalin A affinity chromatographic procedures. The C-lobe and N-lobe fragments of human transferrin were then used in binding assays to assess their ability in binding to the bacterial transferrin receptors. Competitive binding assays demonstrated that the C-lobe fragment of human transferrin binds as well as intact human transferrin to bacterial transferrin receptors from Neisseria meningitidis, Neisseria gonorrhoeae and Haemophilus influenzae. Using isogenic mutants of N. meningitidis deficient in either of the transferrin-binding proteins (Tbps), we demonstrated that both transferrin-binding proteins were able to bind to the C-lobe fragment of human transferrin.
authors.affiliation: Department of Microbiology and Infectious Diseases, University of Calgary, Alberta, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Alcantara
authors.forename: R H
authors.initials: RH
authors.lastname: Yu
authors.forename: A B
authors.initials: AB
authors.lastname: Schryvers
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D006193:Haemophilus influenzae / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000378:metabolism; D007781:Lactoferrin / Q000378:metabolism*; D016978:Mannheimia haemolytica / Q000378:metabolism; D009344:Neisseria gonorrhoeae / Q000378:metabolism; D009345:Neisseria meningitidis / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism*; D011485:Protein Binding; D011990:Receptors, Transferrin / Q000378:metabolism*; D013045:Species Specificity; D014168:Transferrin / Q000378:metabolism*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D010446:Peptide Fragments; D011990:Receptors, Transferrin; D014168:Transferrin; D007501:Iron; D007781:Lactoferrin