Iwakoshi E, Hisada M, Minakata H
Suntory Institute for Bioorganic Research, 618-8503, Osaka, Japan.
Peptides. 2000 May;21(5):623-30. 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.
