title: Achatin-I, an endogenous neuroexcitatory tetrapeptide from Achatina fulica Férussac containing a D-amino acid residue.
abstract: 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.
authors.affiliation: Suntory Institute for Bioorganic Research, Osaka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kamatani
authors.forename: H
authors.initials: H
authors.lastname: Minakata
authors.forename: P T
authors.initials: PT
authors.lastname: Kenny
authors.forename: T
authors.initials: T
authors.lastname: Iwashita
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
authors.forename: K
authors.initials: K
authors.lastname: Funase
authors.forename: X P
authors.initials: XP
authors.lastname: Sun
authors.forename: A
authors.initials: A
authors.lastname: Yongsiri
authors.forename: K H
authors.initials: KH
authors.lastname: Kim
authors.forename: P
authors.initials: P
authors.lastname: Novales-Li
mesh_terms: 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
chemical_list: D000596:Amino Acids; D009479:Neuropeptides; C059927:achatin I