Polypeptides elastomeric

Keywords Elastin Elastin-like polypeptides Elastomeric polypeptides Resilin Resilin-like polypeptides... 

This polypeptide is structurally identical to ABA-type triblock copolymer with a central hydrophdic elastomeric end-block capped with two hydrophobic plastic end-blocks and exhibits amphiphilic characteristics. The end-blocks of the polymer were chosen in such a way that their LCST would reside at or near room temperature. Thus the polymer exhibits phase separation, which is analogue to conventional TPEs, and offers TPE gels under physiological relevant conditions [104]. Glutamic acid residue is placed periodically in the elastomeric mid-block to increase its affinity towards the aqueous... 

Elastomeric polypeptides are a class of very interesting biopolymers and are characterized by mbber-like elasticity, large extensibility before rupture, reversible deformation without loss of energy, and high resilience upon stretching. Their useful properties have motivated their use in a wide variety of materials and biological applications. Here, we focus on two elastomeric proteins and the recombinant polypeptides derived thereof. 

The first elastomeric protein is elastin, this structural protein is one of the main components of the extracellular matrix, which provides stmctural integrity to the tissues and organs of the body. This highly crosslinked and therefore insoluble protein is the essential element of elastic fibers, which induce elasticity to tissue of lung, skin, and arteries. In these fibers, elastin forms the internal core, which is interspersed with microfibrils [1,2]. Not only this biopolymer but also its precursor material, tropoelastin, have inspired materials scientists for many years. The most interesting characteristic of the precursor is its ability to self-assemble under physiological conditions, thereby demonstrating a lower critical solution temperature (LCST) behavior. This specific property has led to the development of a new class of synthetic polypeptides that mimic elastin in its composition and are therefore also known as elastin-like polypeptides (ELPs). 

Fig. 20 Modular resilin-like polypeptide containing domains conferring elastomeric properties, heparin molecule interaction, cell adhesion, and matrix metalloproteinase (MMP) proteolysis. Lysine residues are encoded periodically to permit crosslinking...

Despite the foregoing evidence, the type-II p-tum has not been unequivocally established as the determinative element for the development of elastomeric behavior within the elastomeric domains of elastin and other native polypeptide materials. Spectroscopic analyses of native elastin and elastin-mimetic polypeptides have provided strong evidence for the presence of alternative conformations, particularly above the inverse transition temperature, which may contribute to the elastomeric behavior of the material in its coacervate state. In addition, the elastomeric domains of native tropoelastin display quite substantial sequence diversity, although it appears that Pro-Gly sequences are conserved... 

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