Detection of Dihydroxyphenylalanine in Native Foot Proteins from Mytilus coruscus Byssus

The amino acid 3,4-l-dihydroxyphenylalanine (DOPA) can be detected in a variety of foot proteins in mussel. The quantification of DOPA in proteins is essential to understand its role in mussel adhesion. DOPA can be detected with considerable sensitivity with nitroblue tetrazolium /Glycinate(NBT/Glycinate) staining. The Mytilus coruscus byssal proteins were experimented for the detections of the DOPA content,protein distribution,and adhesive ability of foot proteins from thread and plaque with electrophoresis and coating assay as well. We found that the average DOPA content in proteins of plaques was about 2. 33 times higher than that of thread. The adhesive proteins of byssal plaque contained more DOPA and low molecular weight contents than those from the thread with the intensity difference about four folds as determined by PQuest semi-quantitative analysis. The coating ability on glass of the plaque proteins was greater than that of the thread proteins,which correlated with the difference in the protein composition. Our data may help to understand the functional diversity of adhesive proteins in mussel adhesion.