Elastomeric proteins are characterized by their large extensibility before rupture, reversible deformation without loss of energy, and high resilience upon stretching. Motivated by their unique mechanical properties, there has been tremendous research in understanding and manipulating elastomeric polypeptides, with most work conducted on the elastin but more recent work on an expanded set of polypeptide elastomers and it has been possible to manipulate the physical properties and conformation of these material. The literature data and analyses [1] affirm that components of elastin, and purified elastin fiber itself contain dynamic, non-random, regularly repeating structures that exhibit dominantly entropic elasticity by means of a damping of internal chain dynamics on extension. The resulting structure, termed ?-spiral, as the ?-turn is the dominant repeating secondary structural feature. These studies revealed the presence of two different types of conformers; folded or semi-folded conformation consisting of ?-turns and extended conformations. Interestingly, Tatham and coworkers[1] have shown that the elastic modulus of HMW wheat gluten subunits crosslinked by ?-irradiation, similar to that of the crosslinked elastin polypentapeptide poly(VPGVG). Wheat glutenin is the main elastomeric protein in plants. The high molecular weight (HMW) subunits of wheat gluten are seed storage proteins, for storage of essential nutrients such as carbon, nitrogen and sulfur for growth of seedlings. The hexa-amino-acid repeats PGQGQQ and the nona-amino-acid repeats GYYPTSPQQ in the protein are considered to be mainly responsible for the elasticity of wheat gluten[2]. CD and FTIR spectroscopy on the short peptides based on the repeat motifs of the HMW subunits of gluten suggested the presence of ?-turns between the repeats. The glutenin contains repetitive ?-turns which could lead to formation of ?-spirals as hypothesized for elastin [2], but in addition to the entropic component, enthalpic contributions related to the extensive hydrogen bonding within and between the subunits is also proposed to contribute to the total elastomeric force .
Structural, Conformational, and Dynamical Properties of Repeat Motif in Wheat Gluten Protein.
E Fenude;M Saviano
2017
Abstract
Elastomeric proteins are characterized by their large extensibility before rupture, reversible deformation without loss of energy, and high resilience upon stretching. Motivated by their unique mechanical properties, there has been tremendous research in understanding and manipulating elastomeric polypeptides, with most work conducted on the elastin but more recent work on an expanded set of polypeptide elastomers and it has been possible to manipulate the physical properties and conformation of these material. The literature data and analyses [1] affirm that components of elastin, and purified elastin fiber itself contain dynamic, non-random, regularly repeating structures that exhibit dominantly entropic elasticity by means of a damping of internal chain dynamics on extension. The resulting structure, termed ?-spiral, as the ?-turn is the dominant repeating secondary structural feature. These studies revealed the presence of two different types of conformers; folded or semi-folded conformation consisting of ?-turns and extended conformations. Interestingly, Tatham and coworkers[1] have shown that the elastic modulus of HMW wheat gluten subunits crosslinked by ?-irradiation, similar to that of the crosslinked elastin polypentapeptide poly(VPGVG). Wheat glutenin is the main elastomeric protein in plants. The high molecular weight (HMW) subunits of wheat gluten are seed storage proteins, for storage of essential nutrients such as carbon, nitrogen and sulfur for growth of seedlings. The hexa-amino-acid repeats PGQGQQ and the nona-amino-acid repeats GYYPTSPQQ in the protein are considered to be mainly responsible for the elasticity of wheat gluten[2]. CD and FTIR spectroscopy on the short peptides based on the repeat motifs of the HMW subunits of gluten suggested the presence of ?-turns between the repeats. The glutenin contains repetitive ?-turns which could lead to formation of ?-spirals as hypothesized for elastin [2], but in addition to the entropic component, enthalpic contributions related to the extensive hydrogen bonding within and between the subunits is also proposed to contribute to the total elastomeric force .I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
