Mussel glue fromMytilus californianus Conrad: a comparative study

Summary Marine mussels secrete a byssus in order to attach to solid surfaces in the sea. The polyphenolic protein is the glue in the adhesive plaques of the byssus. InMytilus californianus, the polyphenolic protein has an apparent molecular weight of 85,000±5,000 and is rich in the amino acids lysine, 3,4-dihydroxyphenylalanine, serine, threonine, and hydroxyproline. In composition it resembles the polyphenolic protein ofM. edulis (M _r=125,000), although theM. edulis protein contains significantly less isoleucine and more alanine. Tryptic digestion ofM. californianus polyphenolic protein revealed two types of repeating decapeptides (1) (Ser/Thr)-Thr-(Tyr/Dopa)-Hyp-Hyp-Thr-Dopa-Lys-Hyp-Lys and (2) Ile-(Thr/Ser)-(Tyr/Dopa)-Hyp-Hyp-Thr-Dopa-Lys-Hyp-Lys. Residues 2 to 8 are identical with residues 4–10 inM. edulis decapeptides.Abbreviation Dopa 3,4hydroxyphenylalanine