Mussel collagen

Resilin and elastin have relatively high extensibility and resilience, but as compared to the collagen and the silks, the proteins sacrifice stiffness (elastic modulus) and strength (see Table 2). Collagen and dragUne sflk are much stiffer materials, but lack the extensibility that is characteristic of the rubber-like proteins. On the other hand, the mussel byssus fibers and the viscid silk have the extensibility of resilin and elastin, but lack the resilience [208]. 

Dihydroxyproline (3) was isolated from animal adhesive protein (Melp 1) found in the mussel Mytilus edulis, and its 2R,3S,4R) analogue 4 was also isolated from natural sources. (2ii ,3 )-3-Hydroxyproline (5) was isolated from dried Mediterranean sponge and telomycin, while its (25, 3 )-isomer 6 was obtained only from telomycin. " (25, 35 )-3-Hydroxyproline (7) was found in naturally occurring peptides, namely mucrorin-telomycin and bovine Achilles tendon collagen. ... 

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. 

Bdolah, A., KeUer, P.J., 1976. Isolation of collagen granules from the foot of the sea mussel, Mytilus califomianus. Comp. Biochem. Physiol. B 55 (2), 171—174. 

Suiimi is a concentrate of insoluble muscle proteins (ca. 20%). It forms a solid cohesive gel with water (ca. 80%), which solidifies when warm For production, lean fish meat is ground at 5-10 °C and extracted with water until basically only myosin, actin, actomyosin and small amounts of collagen remain. The addition of paramyosin (cf. 13.1.4.2.2) intensifies the structure of the gel. In the further processing of Surimi to Kamboko, starch (ca. 5%), egg white, flavor enhancers, colorants and aroma substances are added, whereby an attempt is made to imitate crab or mussel meat. The resulting mixture is solidified by denaturation of the proteins first at 40-50 °C and then at 80-90 °C. Fibrous structures are produced by extrusion. 

Structural proteins such as collagen, elastin, and spider silk contain repeating sequences of amino acids. In 1983, Waite discovered that the protein secreted by the phenol gland of the blue sea mussel Mytilus edulis consists of closely related decapeptide and hexapeptide sequences with a combined molecular weight of approximately 130 kilodaltons (kDa).i He further elucidated that this protein is transformed into glue through enzymatic oxidation to form the adhesive plaques that anchor the mussel... 

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-... 

To develop a mechanistic scheme for glue formation at the molecular level, it is important to know which amino acids in the mussel adhesive protein and collagen are oxidized and to follow the fate of these amino acids in subsequent secondary reactions such as crosslinking, complexa-tion, degradation, etc. Once the sequence of chemical events is established, it can be applied to the three-dimensional structures of mussel glue protein and collagen to develop a rational model for glue formation. 

Haningtrai MJ, Gupta HS, Fratzl P, Waite JH (2009) Collagen insulated from tensile damage by dmnains that unfold reversibly in situ X-ray investigation of mechanical yield and damage repair in the mussel byssus. J Struct Biol 167 47-54... 

Waite JH, Qin XX, Coyne KJ (1998) The peculiar collagens of mussel byssus. Matrix Biol 17 93-106... 

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