Structural characterization of lipopeptide agonists for the bradykinin B2 receptor.
The conformational features of Pam-Lys(0)-Arg(1)-Pro(2)-Pro(3)-Gly(4)-Phe(5)-Ser(6)-Pro(7)-Phe(8)-Arg(9)-OH (PKD) and Pam-Gly(-1)-Lys(0)-Arg(1)-Pro(2)-Pro(3)-Gly(4)-Phe(5)-Ser(6)-Pro(7)-Phe(8)-Arg(9)-OH (PGKD), the Pam-Lys and Pam-Gly-Lys analogues of bradykinin, have been determined by high-resolution NMR in a zwitterionic lipoid environment. Radical-induced relaxation of the (1)H NMR signals was used to probe the topological orientation of the peptides with respect to the zwitterionic lipid interface. The radical-induced relaxation and molecular dynamics (MD) data indicated that the palmitic acid and N-terminal amino acid residues embed into the micelles, while the rest of the polypeptide chain is closely associated with the water-micelle interface. Throughout the entire nuclear Overhauser effect restrained MD simulation, a nonideal type I beta-turn was observed in the C-terminus of PKD between residues 6 and 9, and a gamma-turn was observed in the C-terminus of PGKD between residues 6 and 7. Therefore, the additional glycine has a dramatic effect on the structural preferences of the biologically important C-terminus, an effect brought about by the interaction with the lipid environment. These structural features are correlated to the biological activity at the bradykinin B2 receptor.
Department of Chemistry, Brown University, Providence, RI 02912, USA.
C
C
Giragossian
E
E
Nardi
C
C
Savery
M
M
Pellegrini
S
S
Meini
C A
CA
Maggi
A M
AM
Papini
D F
DF
Mierke
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis*; D000818:Animals; D001667:Binding, Competitive; D001920:Bradykinin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D019556:COS Cells / Q000378:metabolism; D006801:Humans; D055666:Lipopeptides; D008074:Lipoproteins / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D018002:Receptors, Bradykinin / Q000819:agonists*; D013329:Structure-Activity Relationship
D000596:Amino Acids; D055666:Lipopeptides; D008074:Lipoproteins; C425264:Pam-Gly(-1)-Lys(0)-Arg(1)-Pro(2)-Pro(3)-Gly(4)-Phe(5)-Ser(6)-Pro(7)-Phe(8)-Arg(9)-OH; C425265:Pam-Lys(0)-Arg(1)-Pro(2)-Pro(3)-Gly(4)-Phe(5)-Ser(6)-Pro(7)-Phe(8)-Arg(9)-OH; D018002:Receptors, Bradykinin; D001920:Bradykinin