Nonapeptide corresponding to the sequence 27-35 of the mature human IL-2 efficiently competes with rIL-2 for binding to thymocyte receptors [corrected].
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].
Zav'yalov
V P
VP
Institute of Immunology, Moscow, U.S.S.R.
Navolotskaya
E V
EV
Isaev
I S
IS
Kaurov
O A
OA
Kolobov
A A
AA
Vasilenko
R N
RN
Galaktionov
V G
VG
Denesyuk
A I
AI
D000818:Animals; D001665:Binding Sites / Q000276:immunology; D001667:Binding, Competitive / Q000276:immunology; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D009842:Oligopeptides / Q000378:metabolism*; D015375:Receptors, Interleukin-2 / Q000378:metabolism*; D011994:Recombinant Proteins; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D013950:Thymus Gland / Q000378:metabolism*
D007376:Interleukin-2; D009842:Oligopeptides; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins