A New Iq-Peptide of the Kunitz Type from the Heteractis magnifica Sea Anemone Exhibits Neuroprotective Activity in a Model of Alzheimer's Disease

The HMIQ3c1 recombinant peptide (6434 Da), the Kunitz-type protease inhibitor, which belonged to the new group of the IQ-peptides from the Heteractis magnifica sea anemone was prepared. The inhibitory constant of trypsin by this peptide proved to be 5.0 x 10(-8) M. rHMIQ3c1 was shown to have no interaction with eight isoforms of Kv1 channels. This peptide exhibited neuroprotective activity in a concentration of 10 mu M, and the peptide increased the viability of cells of the Neuro2a murine neuroblastoma by 39.4 +/- 6.6% in the presence of beta-amyloid. However, the peptide did not influence the viability of the cells during their incubation with 6-hydroxydofamine.