Stabilization of alpha-helix in C-terminal fragments of neuropeptide Y.
To elucidate the alpha-helix-stabilizing effect of amino acids at the helical ends, we prepared analogs of C-terminal fragments of neuropeptide Y (NPY) containing an alpha-helical part. The helix-stabilizing tendency of N-terminal amino acid in NPY (12-36) was found to be as follows: Thr > Ser > Gly > Gln > Cys > Asn > Asp > Val > Phe > Glu > Lys > Tyr > Ala = Trp > His > Arg, suggesting the importance of end capping. The capping effect was not evident when N-termini in NPY (11-36) and NPY (13-36) were replaced. Under the same conditions as those for the receptor binding, [Thr12]NPY (12-36) had about 4-fold higher alpha-helix content than [Arg12]NPY (12-36). However, there was no apparent relationship between the helix content and binding affinity to the Y2 receptor.
Yumoto
N
N
Government Industrial Research Institute, Osaka, Japan.
Murase
S
S
Hattori
T
T
Yamamoto
H
H
Tatsu
Y
Y
Yoshikawa
S
S
D000595:Amino Acid Sequence; D000596:Amino Acids; D000818:Animals; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D002942:Circular Dichroism; D004355:Drug Stability; D006624:Hippocampus / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000737:chemistry* / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D017433:Protein Structure, Secondary; D017476:Receptors, Neuropeptide Y / Q000378:metabolism; D013552:Swine
D000596:Amino Acids; D009478:Neuropeptide Y; D010446:Peptide Fragments; D017476:Receptors, Neuropeptide Y