Cardioactive peptides isolated from the brain of a Japanese octopus, Octopus minor

• Published in: Peptides (New York, N.Y. : 1980) Vol. 21; no. 5; pp. 623 - 630
• Main Authors: Iwakoshi, Eiko, Hisada, Miki, Minakata, Hiroyuki
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2000
• Subjects: Amino Acid Sequence; Animals; Brain Chemistry; Chromatography, High Pressure Liquid; Chromatography, Ion Exchange; d-amino acid-containing peptides; Heart - drug effects; In Vitro Techniques; Marine; Muscle Contraction - drug effects; Octopodiformes; Octopus cardioactive peptides; Octopus minor; Peptides - chemistry; Peptides - isolation & purification; Peptides - pharmacology; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Time-of-flight MS analysis; INW, Japan; Octopus cardioactive peptides; d-amino acid-containing peptides; Time-of-flight MS analysis
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/S0196-9781(00)00201-1

Octopus cardioactive peptides (Ocp-1: Gly- d-Phe-Gly-Asp, and Ocp-3: Gly-Ser-Trp-Asp) were isolated from brain extracts of the octopus, Octopus minor, using the isolated systemic heart as a bioassay. These peptides showed both positive chronotropic and inotropic effects on the heart. The stereoisomers at position 2 were also isolated, but their activities were only 1/10 3-1/10 4 those of the corresponding isomers. The presence of the peptides in the systemic heart was confirmed by time-of-flight mass spectrometry (MS) and tandem MS analysis. The results suggested that Ocp-1 and Ocp-3 might be involved in excitatory control of the octopus cardiovascular system as neuropeptides and/or neurohormones.