1. Nonapeptide corresponding to the sequence 27-35 of the mature human IL-2 efficiently competes with rIL-2 for binding to thymocyte receptors [corrected].
- Author
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Zav'yalov VP, Navolotskaya EV, Isaev IS, Kaurov OA, Kolobov AA, Vasilenko RN, Galaktionov VG, and Denesyuk AI
- Subjects
- Animals, Binding Sites immunology, Binding, Competitive immunology, Humans, Lymphocyte Activation immunology, Mice, Recombinant Proteins, Spleen immunology, T-Lymphocytes immunology, Interleukin-2 metabolism, Oligopeptides metabolism, Receptors, Interleukin-2 metabolism, Thymus Gland metabolism
- Abstract
Previously it was shown [1] that amino acid substitutions at the region of the first alpha-helix of IL-2 specifically inactivate its reactivity with the intermediate-affinity receptor p70, and mutations in the fifth alpha-helix specifically inactivate the binding to the low-affinity receptor p55. We have synthesized the peptides corresponding to the putative binding site of IL-2 with the intermediate-affinity receptor p70 and found that the nonapeptide corresponding to the sequence 27-35 of the mature IL-2 [2] effectively competes with human rIL-2 for binding to thymocyte receptors. Two types of nonapeptide receptors were revealed: those with Kd1 = 1.84 x 10(-8) M and Kd2 = 1.6 x 10(-7) M. The rIL-2 provides a 100% inhibitory effect on the binding of the 125I-labeled nonapeptide to thymocyte receptors, Ki = 3.5 x 10(-8) M. Low immunoproliferative activity of the peptide allows one to recommend it as a specific antiproliferation drug, IL-2 inhibitor [corrected].
- Published
- 1992
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