Purification of adhesive proteins from mussels

Tissue Adhesives: From Research to Clinical Translation

Sutures, staples, clips and skin closure strips are used as the gold standard to close wounds after an injury. In spite of being the present standard of care, the utilization of these conventional methods is precarious amid complicated and sensitive surgeries such as vascular anastomosis, ocular surgeries, nerve repair, or due to the high-risk components included. Tissue adhesives function as an interface to connect the surfaces of wound edges and prevent them from separation. They are fluid or semi-fluid mixtures that can be easily used to seal any wound of any morphology - uniform or irregular. As such, they provide alternatives to new and novel platforms for wound closure methods. In this review, we offer a background on the improvement of distinctive tissue adhesives focusing on the chemistry of some of these products that have been a commercial success from the clinical application perspective. This review is aimed to provide a guide toward innovation of tissue bioadhesive materials and their associated biomedical applications.

Design strategies and applications of tissue bioadhesives

In the past two decades tissue adhesives and sealants have revolutionized bleeding control and wound healing. This paper focuses on existing tissue adhesive design, their structure, functioning mechanism, and their pros and cons in wound management. It also includes the latest advances in the development of new tissue adhesives as well as the emerging applications in regenerative medicine. We expect that this paper will provide insightful discussion on tissue bioadhesive design and lead to innovations for the development of the next generation of tissue bioadhesives and their related biomedical applications.

Egg attachment of the asparagus beetle Crioceris asparagi to the crystalline waxy surface of Asparagus officinalis

Plant surfaces covered with crystalline epicuticular waxes are known to be anti-adhesive, hardly wettable and preventing insect attachment. But there are insects that are capable of gluing their eggs to these surfaces by means of proteinaceous secretions. In this study, we analysed the bonding region between the eggs of Crioceris asparagi and the plant surface of Asparagus officinalis using light and cryo-scanning electron microscopy. The wettability of the plant surface by egg secretion was compared with that by Aqua Millipore water, aqueous sugar solution and chicken egg white. Furthermore, the force required to remove C. asparagi eggs from the plant surface was measured, in order to evaluate the egg's bonding strength. Mean pull-off force was 14.7 mN, which is about 8650 times higher than the egg weight. Egg glue was observed spreading over the wax crystal arrays on the plant cladophyll and wetting them. Similar wetting behaviour on the A. officinalis surface was observed for chicken egg white. Our results support the hypothesis that the mechanism of insect egg adhesion on micro- and nanostructured hydrophobic plant surfaces is related to the proteinaceous nature of adhesive secretions of insect eggs. The secretion wets superhydrophobic surfaces and after solidifying builds up a composite, consisting of the solidified glue and wax crystals, at the interface between the egg and plant cuticle.

Understanding marine mussel adhesion

In addition to identifying the proteins that have a role in underwater adhesion by marine mussels, research efforts have focused on identifying the genes responsible for the adhesive proteins, environmental factors that may influence protein production, and strategies for producing natural adhesives similar to the native mussel adhesive proteins. The production-scale availability of recombinant mussel adhesive proteins will enable researchers to formulate adhesives that are water-impervious and ecologically safe and can bind materials ranging from glass, plastics, metals, and wood to materials, such as bone or teeth, biological organisms, and other chemicals or molecules. Unfortunately, as of yet scientists have been unable to duplicate the processes that marine mussels use to create adhesive structures. This study provides a background on adhesive proteins identified in the blue mussel, Mytilus edulis, and introduces our research interests and discusses the future for continued research related to mussel adhesion.

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 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.

The adhesive protein of Choromytilus chorus (Molina, 1782) and Aulacomya ater (Molina, 1782): a proline-rich and a glycine-rich polyphenolic protein

The adhesive polyphenolic proteins from Aulacomya ater and Choromytilus chorus with apparent molecular masses of 135000 and 105000, respectively, were digested with trypsin and the peptides produced resolved by reversed phase liquid chromatography. About 5 and 12 major peptides were obtained from the protein of A. ater and C. chorus, respectively. The major peptides were purified by reverse-phase chromatography and the amino acid sequence indicates that both polyphenolic proteins consisted of repeated sequence motifs in their primary structure. The major peptides of A. ater contain seven amino acids corresponding to the consensus sequence AGYGGXK, whereas the tyrosine was always found as 3, 4-dihydroxyphenylalanine (Dopa), the X residue in position 6 was either valine, leucine or isoleucine, and the carboxy terminal was either lysine or hydroxylysine. On the other hand, the major peptides of C. chorus ranged in size from 6 to 21 amino acids and the majority correspond to the consensus sequence AKPSKYPTGYKPPVK. Both proteins differ markedly in the sequence of their tryptic peptides, but they share the common characteristics of other adhesive proteins in having a tandem sequence repeat in their primary structure.

Environmental bioadhesion: themes and applications

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.

Nuclear Sm antigens in the sperm of different organisms

Immunoblot analysis of sperm protein from several species revealed the presence of polypeptides recognised by anti-Sm sera obtained from patients with systemic lupus erythematosus. Immunoreactive polypeptides in human, bull, mouse and rat sperm were identified as protein B', B and D as compared with the Sm polypeptides of HeLa cells. In the sperm of rooster, the teleost fish Cyprinus carpio and the mussel Choromytilus chorus, the immunoreactive polypeptide profile was more complex. To ascertain the sperm origin of the Sm antigens, immunolocalisation with anti-Sm serum was carried out. The results demonstrated that in all the species studied staining was confined to the sperm nucleus, confirming that some polypeptides of the small nuclear ribonucleoprotein complex are present in the gamete.