Structural and functional heterogeneity of the amino-terminal receptor-binding domain of human interferon-alpha 2

E Kontseková1, H Liptáková, V Mucha

  • 1Department of Microbiology and Virology, Comenius University, Bratislava, Slovakia.

Structural immunoanalysis of human interferon (IFN)-alpha 2c revealed antigenic and functional heterogeneity in its N-terminal receptor-binding domain (loop AB). Monoclonal antibodies (mAbs) mapped to the region 30-53 of IFN-alpha 2 defined three partially overlapping antigenic sites designated here as 'a', 'b' and 'c'. For the high-affinity binding of IFN-alpha 2c to the cellular receptor, site b located in segment 34-41 and site c (residues 43-53) appeared to be most important. Only the part of site a (amino acids 30-33) seemed to be involved in the interaction with receptor. The segment of residues 30-46 forms a relatively straight structure on the protein surface, according to the three-dimensional model of human IFN-alpha 2.

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