Fol. Biol. 2002, 48, 96-101
Characterization of Functional Domains of Human Interferon Gamma by Specific Monoclonal Antibodies
For the study of functional domains of hIFNγ, two MABs were characterized. Both MABs, named 1E11 and 5D6, were sequence-specific for hIFNγ. According to the estimated additivity index, they recognized epitopes located at distinct non-overlapping areas of the hIFNγ molecule. When pre-incubated with hIFNγ, MAB 1E11 was able to neutralize the antiviral as well as the antiproliferative activity of the cytokine. This indicated that MAB 1E11 was specific either for the domain responsible for binding to the cell receptor or for a domain required for both functions. By contrast, the second MAB 5D6 did not interfere with any of the two hIFNγ biological activities. The epitope of MAB 5D6 was located between the amino acid residues Leu 135 and Glu 143 by using different forms of C-terminally truncated hIFNγ. These data allow the conclusion that the last nine C-terminal amino acids are not essential for the receptor binding and biological functioning of this cytokine. The possible role of hIFNγ C-terminus in the intracellular cascade of events is discussed.
Keywords
human interferon gamma, monoclonal antibodies, interferon gamma, biological activity, recombinant protein, interferon gamma C-terminal end.
Funding
This study is supported by grants Nos. A 1-5/2286 from the Swedish Council for Planning and Coordination of Research and K-802/1998 form the Bulgarian National Research Fund.
References
Copyright
This is an open-access article distributed under the terms of the Creative Commons Attribution License.