A H-1-NMR STUDY OF THE SOLUTION CONFORMATION OF ICARIA CHEMOTACTIC PEPTIDE AND ITS [LYS7] ANALOG - EFFECTS ON THE PHYSIOLOGICAL-ACTIVITY OF A SUBSTITUTION OF PROLINE TO LYSINE AT POSITION-7

Solution conformations of Icaria chemotactic peptide isolated from the Ropalidian wasp venom and its [Lys7] analog have been analyzed by the use of two-dimensional proton nuclear resonance spectroscopy. It has been shown that Icaria chemotactic peptide takes α helical conformation in the C-terminal 8-13 segment with the N-terminal 1-7 segment disordered. By contrast, the [Lys7] analog takes α helical conformation over a wider range from residues 3 to 13. The present results indicate that the substitution of proline to lysine at position 7 results in a drastic change in solution conformation, providing the Icaria chemotactic peptide with new physiological functions. © 1990.