A novel D-amino-acid-containing peptide isolated from Aplysia heart.
A novel cardio-excitatory peptide was purified from the hearts of Aplysia kurodai. The peptide was a tripeptide containing a D-amino acid residue in the second position, Asn-D-Trp-Phe-NH2 (NdWFamide). NdWFamide increased the amplitude of contractions of the perfused Aplysia heart with little effect on beating frequency, showing a threshold of approximately 10(-11) M. The peptide also potentiated spontaneous contractions of the anterior aorta. The synthetic peptide having L-Trp instead of D-Trp was about 1,000 times less potent than the native one. NdWFamide seems to play an important role in regulation of cardiac activity in Aplysia.
Morishita
F
F
Department of Biological Science, Faculty of Science, Hiroshima University, Japan. morishit@alpha04.sci.hiroshima-u.ac.jp
Nakanishi
Y
Y
Kaku
S
S
Furukawa
Y
Y
Ohta
S
S
Hirata
T
T
Ohtani
M
M
Fujisawa
Y
Y
Muneoka
Y
Y
Matsushima
O
O
D000818:Animals; D001048:Aplysia / Q000502:physiology*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006321:Heart / Q000502:physiology*; D006325:Heart Atria; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology*; D009206:Myocardium / Q000737:chemistry*; D009479:Neuropeptides / Q000737:chemistry / Q000302:isolation & purification*; D009842:Oligopeptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
D009479:Neuropeptides; D009842:Oligopeptides; C109335:asparaginyl-tryptophyl-phenylalaninamide