Purification and characterization of molecular species of collagen in the skin of skate (Raja kenojei)

Two types, one major and the other minor, of collagen were obtained from pepsin-solubilized collagen of the skate (Raja kenojei) skin. The major collagen was identified as Type I collagen because of a similar characteristic to those of Type I collagens from the skate muscle and cartilage. On the other hand, the SDS–PAGE pattern and peptide maps of the minor collagen were different from those of Type V and XI collagens of the skate muscle and cartilage, respectively. However, the minor collagen was similar, in amino acid composition, to Type V collagen from the skate muscle. These results suggest the existence of a molecular subspecies of Type V collagen in skate skin which is different from the muscle Type V collagen in primary structure or subunit composition.