Polyphenolic protein adhesive

The polyphenolic adhesive protein of the mussel Mytilus edulis is an unusual protein composed mainly of repetitive decapeptide and hexapeptide sequences. In the mussel, the protein is first produced in a precursor form and is converted to an adhesive by post-translation-al modification. To develop an efficient renewable resource for production of the polyphenolic protein, we have used genetic engineering technology. cDNA sequences encoding portions of the polyphenolic protein were identified and expressed in the yeast Saccharomyces cerevisiae. 

For the production of many recombinant proteins, cellular insolubility is a major problem because it is often difficult to achieve biological activity starting with such products (57). However, because the polyphenolic protein produced in vivo is a preadhesive, in vitro activation to the adhesive form is required. Therefore, in vivo insolubility may actually be desirable in the case of the polyphenolic protein because this could result in increased resistance to yeast proteases and better product uniformity and quantity. 

Conversion of the Microbially Produced Preadhesive to an Adhesive Protein. The polyphenolic protein purified from yeast adheres to a wide variety of surfaces including glass and plastic. The adherence probably results from the presence of many polar residues capable of hydrogen bonding and lysine residues that can form ionic interactions. However, this protein does not generate water-resistant bonds to surfaces nor does it have cohesive strength. For those purposes, it is necessary to convert at least a portion of the tyrosine residues to dopa and permit crosslink formation to occur after surface adhesion is achieved. That is, it is necessary to mimic the natural mussel process in which the dopa form of the polyphenolic protein is applied and then rapidly... 

Mushroom tyrosinase has previously been used to convert tyrosine residues in chemically synthesized polyphenolic decapeptides to dopa residues (38), This enzyme also can convert dopa residues to quinones, but the enzymatic product can be maintained in the dopa form if reducing conditions are utilized. Using mushroom tyrosinase, we have converted at least 50% of the tyrosine residues to dopa and have evidence for quinone-lysine crosslinks in an oxidizing environment (T. Wei and R. Link, unpublished data). When these conditions are carefully controlled, we have observed adhesive properties for the recombinant polyphenolic protein. We are currently studying the parameters that can increase adhesivity and moisture resistance through better surface interactions and more extensive crosslinking. 

The polyphenolic protein extracted from the phenol gland does not possess adhesive properties. However, it becomes a glue when it is blended with collagen and subjected to enzymatic oxidation.The participation of collagen in glue formation has been confirmed by Waite.When the mussel finds a solid surface on which to anchor itself, it must first displace the water from the surface and spread the glue composite to establish a foothold. This is possible only if the glue composite con-... 

Papov, V.V., Diamond, TV., Biemann, K., and Waite, J.H. (1995) Hydroxyarginin-containing polyphenolic proteins in the adhesive plaques of the marine mussel Mytilus edulis. J. Biol. Chem., 270, 20183-20192. 

The area of natural adhesives has progressed enormously in recent years, spanning from medical applications, particularly in dentistry, to everyday articles, such as shoes. Byssus, from mytilids, has great strength and elasticity deriving from a polyphenolic proteic stmcture (Waite 1998). Proteins secreted by oyster pearls also form highly strong threads (Yamamoto 1995). 

Expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) is known to be elevated at sites of inflammation. Studies have been conducted into the effects of EGCG and TF-3 on the expression of these adhesion molecules induced by interleukin-ip (IL-lp) in cultured human umbilical vein endothelial cells (HUVECs). Both compounds significantly inhibited IL-ip-induced protein expression of VCAM and ICAM in dose-dependent manners and were associated with reduced adhesion of leukocytes to HUVECs. The m-RNA level of VCAM-1 was also inhibited by these tea polyphenolics, as was the NF-KB-dependent transcriptional activity induced by IL-lp. It is concluded that these molecules exhibit anti-inflammatory and anti-invasion properties, probably via a route involving blockage of IkB kinase. 

Bioadhesives may basically consist of proteins, polysaccharides, polyphenols, and hpids. These substances occur mostly in combination. The adhesives of the well-studied blue mussel Mytilus edulis) and of barnacles are proteinaceous materials. Other well-known proteins with adhesive properties are elastin, collagen, fibronectin, laminin, fibrinogen, and keratin. 

Most stains consist of colored substances of natural origin belonging to the polyphenol, carotenoid, or chlorophyll class. Artificial food colorants, cosmetic ingredients, and decorative dyes complete the stain portfolio. Very often stains are complex mixtures of spilled food preparations or beverages. Combined with oils, fats, or other organic material, such as proteins, starch, or waxes, the properties of stains are quite different from those of isolated dyes. Only a small proportion of all stains is fixed on surfaces by physical adhesion. On fibers, in particular, strong interactions often result in covalent bond formation. This process is more important on cotton than on synthetic fabrics. 

---