Visit our Expo - Redox and Inflammation signaling 2012

Session I : protein domains Poster I, 1
Synthetic corticotropin-like peptide GKVLKKRR, corresponding to the fragment 81-88
of human pro-interleukin-1alpha, is an antagonist of corticotropin receptor
Elena V. Navolotskaya, Vera I. Vanina, Alexander A. Kolobov*, Elena A. Kampe-
Nemm*, Valery M. Lipkin
Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the
Russian Academy of Sciences, Science Avenue, 6, 142290 Pushchino, Moscow Region,
Russia, navolots@fibkh.serpukhov.su
*State Research Center for Institute of Highly Pure Bioprepararions, 197110 St.
Petersburg, Russia, kolobov@vs3283.spb.edu
The corticotropin-like octapeptide GKVLKKRR (termed as leucorticotropin), which
corresponds to the amino acid sequence 81-88 in the precursor of human interleukin-1alpha,
was synthesized on automatic peptide synthesizer. Peptide was purified to homogeneity by
reverse-phase HPLC (chromatograph Gilson, France) on Delta Pack C18 column. The
peptide purity was > 99%. Leucorticotropin was labeled with tritium by the high-temperature
solid-state catalytic isotope exchange reaction to specific activity of 20 Ci/mmol. Receptor
binding studies revealed that [3H]leucorticotropin bound with high affinity and specificity to
corticotropin receptor on rat adrenal cortex membranes (Kd = 2.2 nM). Leucorticotropin at
concentrations of 0.1 – 1000 n! was found to have no influence on the adenylate cyclase
activity in adrenal cortex membranes, while intranasal injection of leucorticotropin to rats at
doses of 10 - 50 µg/kg was found to inhibit the secretion of 11-oxycorticosteroids from the
adrenals to the bloodstream. Thus, leucorticotropin is an antagonist of corticotrophin
receptor.
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