BIO325H5 Lecture Notes - Lecture 2: Coiled Coil, Covalent Bond, Ligament
Document Summary
Abductin: a biological rubber employed in hinges of bivalves: protein chains lubricated by water and joined by tyrosine cross-links. Antarctic scallop escapes capture by jet propulsion. The creature launches itself by closing the two halves of its shell with its adductor muscle. The closing action forces water out of the shell"s interior and compresses the rubbery hinge tissue (green). As the hinge tissue rebounds, the shell slowly opens, water re-enters the shell, and the muscle returns to its initial position, ready for another thrust. Blue represents the movement of water, and red represents the force of the adductor muscle. Much like abductin, resilin consists of protein chains joined by covalent bonds cross-linking between tyrosine amino acids (residues) to produce di and tri-tyrosine. This amino acid lacks a side chain and is nonpolar, characteristics that prevent the formation of the sort of electrostatic bonds that would otherwise constrain the shape of the molecule.
