ABSTRACT
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 residues present in these proteins, and polymerization was monitored by acid-urea polyacrylamide gel electrophoresis. The protein from A. ater polymerized at 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 significant change of other amino acids. This suggests that crosslink formation may be limited to the oxidized dopa derivatives of the protein molecules.
Subject(s)
Agaricales/enzymology , Bivalvia/metabolism , Monophenol Monooxygenase/chemistry , Monophenol Monooxygenase/metabolism , Proteins/chemistry , Proteins/metabolism , Animals , Cross-Linking Reagents/metabolism , Dimerization , Substrate SpecificityABSTRACT
Many marine organisms attach to underwater surfaces using protein adhesives. These are basic proteins with high levels of the amino acid 3,4-dihydroxyphenylalanine and an extended flexible conformation. The hydroxylation of tyrosine residues plays a key role in the chemisorption of these polymers to surfaces and in the setting of the adhesive. These unique proteins are attracting biotechnological attention for application in industry and medicine. Recent development on the immobilization of antigens and antibodies, enzymes, cells and tissues, illustrate the great potential use of these adhesives for diagnostics and medicine. The use of these adhesive proteins as anticorrosive coats for metal also suggests important applications for industry.
Subject(s)
Adhesives/isolation & purification , Marine Biology , Proteins/isolation & purification , Adhesiveness , Amino Acid Sequence , Animals , Biotechnology , Bivalvia/chemistry , Bivalvia/genetics , Consensus Sequence , Proteins/geneticsABSTRACT
Polystyrene microtiter plates coated with 0.30 microgram/ well of the adhesive polyphenolic protein purified from the mussel Aulacomya ater showed enhanced capacity to immobilize antigens such as human chorionic gonadotrophin (hCG). Uncoated and coated wells were activated with different amounts of hCG (from 2 to 500 ng), blocked with bovine serum albumin, and tested with anti-hCG monoclonal antibodies and antimouse IgG conjugated with peroxidase. The reading at 492 nm of the uncoated wells activated with 500 ng of hCG was similar to that obtained with coated wells but using 5 to 10 ng of antigen. The coating procedure also resulted in better sensitivity to detect low concentration of monoclonal antibodies and better signal-to-noise ratio. The capacity of the mussel coating to immobilize hCG, as well as the immunoreactivity of the attached antigen, remained stable for several months.
