Preparation and partial characterization of collagen from paper nautilus (Argonauta argo, Linnaeus) outer skin

To make more effective use of limited-resources, collagen was prepared from the outer skin of the paper nautilus. As a result, the outer skin was hardly solubilized in 0.5 M acetic acid (yield: about 5.2% on a dry weight basis). The insoluble matter was easily digested by 10% pepsin (w/v), and a large amount of collagen was obtained with about a 50.0% yield (pepsin-solubilized collagen). The pepsin-solubilized collagen had a chain composition of α1 α2 α3 heterotrimer similar to Callistoctopus arakawai arm collagen. Although the paper nautilus collagen has a denaturation temperature of 27 °C, that is about 10 °C lower than that of the porcine one, this result indicates that it is possible to use the paper nautilus outer skin as an important collagen source.