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Characterization of the diphtheria toxin receptor‐binding domain
Author(s) -
Rolf John M.,
Eidels Leon
Publication year - 1993
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1993.tb01149.x
Subject(s) - diphtheria toxin , corynebacterium diphtheriae , biology , toxin , binding site , amino acid , biochemistry , receptor , peptide sequence , cleavage (geology) , binding domain , peptide , diphtheria , virology , gene , paleontology , vaccination , fracture (geology)
Summary The carboxyl‐terminal region of diphtheria toxin (DT) has been analysed in order to determine regions of receptor recognition. Biochemical cleavage of the toxin with hydroxylamine (HA) was used to generate the peptides HA9DT (residues 454–535), HA6DT (residues 482–535), and HA3DT (residues 454–461). Characterization of HA6DT demonstrated that the final 54 amino acids of DT are sufficient to constitute the receptor‐binding domain of the toxin. Within HA9DT, the region encompassing HA3DT and containing the highly cationic polyphosphate‐binding site did not contribute to the binding ability of HA6DT. Consistent with this observation, HA3DT itself did not compete for binding of radiolabelled DT to Vero cells. A 30‐amino acid synthetic peptide composed of residues 506–535 did not block receptor binding of DT, indicating that residues toward the amino‐terminus of HA6DT, or the entire HA6DT region, are required for receptor recognition.