In vitro polymerization of mussel polyphenolic proteins catalyzed by mushroom tyrosinase

The in vitro enzymatic polymerization of the polyphenolic protein purified from the mussels Aulacomya ater, Mytilus edulis chilensis and Choromytilus chorus was studied. Mushroom tyrosinase was used to oxidize the dopa residu es present in these proteins, and polymerization was monitored by acid-urea polyacrylamide gel electrophoresis. The protein from A. ater polymerized a t a faster rate than the other two. Amino acid analysis of the crosslinked protein showed a notable decrease in the content of dopa, but no significan t change of other amino acids. This suggests that crosslink formation may b e limited to the oxidized dopa derivatives of the protein molecules. (C) 20 00 Elsevier Science Inc. All rights reserved.