Biochemical characterization of a byssal protein from Dreissena bugensis (Andrusov)

The biochemical characterization of Dreissena bugensis foot protein 1 (Dbfp1), a tandemly repetitive, Dopa-containing protein isolated from the foot of the quagga mussel, Dreissena bugensis (Andrusov) is described, Dbfp1 is an acidic glycoprotein containing N-acetylgalactosamine (N-GaINAc) O-linked to threonine residues as a monosaccharide. Primary sequence data reveal that the protein is partly composed of a unique, repeating octapeptide motif rich in glycine. Dbfp1 resembles Dpfp1, a byssal precursor from the congeneric zebra mussel, Dreissena polymorpha (Pallas), in that both proteins contain peptidyl-Dopa, have acidic isoelectric points, and are glycosylated with N-GaINAc. However, the octapeptide motif of Dbfp1 differs from repetitive sequence motifs found in D. polymorpha. The detection of peptidy-Dopa in Dbfp1 further strengthens the hypothesis that the freshwater dreissenids have adopted an adhesive strategy fundamentally similar to that employed by marine mussels.