Achatin-I, an endogenous neuroexcitatory tetrapeptide from Achatina fulica Férussac containing a D-amino acid residue.
A tetrapeptide named achatin-I was purified from the suboesophageal and cerebral ganglia of the African giant snail Achatina fulica Férussac, and evoked a potent neuroexcitatory effect. The amino acid sequence of achatin-I is Gly-D-Phe-Ala-Asp. Achatin-I induced a voltage-dependent inward current, due to Na+, on the identifiable giant neuron, periodically oscillating neuron (PON), of the same snail. All possible isomers of achatin-I were synthesized using the solid-phase method. The sensitivity of the neuron to achatin-I and its isomers was strictly stereospecific; among the various isomers, only achatin-I showed marked effects (ED50 = 2.29 x 10(-6)M), while Gly-D-Phe-D-Ala-Asp, the synthetic D-Ala-isomer, was less than 10(-3) active.
Kamatani
Y
Y
Suntory Institute for Bioorganic Research, Osaka, Japan.
Minakata
H
H
Kenny
P T
PT
Iwashita
T
T
Watanabe
K
K
Funase
K
K
Sun
X P
XP
Yongsiri
A
A
Kim
K H
KH
Novales-Li
P
P
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D004553:Electric Conductivity; D004947:Esophagus / Q000032:analysis; D005724:Ganglia / Q000032:analysis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009479:Neuropeptides / Q000302:isolation & purification / Q000494:pharmacology*; D012908:Snails / Q000032:analysis*; D013237:Stereoisomerism
D000596:Amino Acids; D009479:Neuropeptides; C059927:achatin I