title: Molecular architecture influences the thermally induced aggregation behavior of elastin-like polypeptides.
abstract: Elastin-like polypeptides are thermally responsive polymers that exhibit phase separation above a transition temperature. The effect of molecular architecture on the temperature responsive behavior of elastin-like polypeptide solutions was investigated by characterization of solutions of three-armed star polypeptides, linear polypeptides, and their mixtures. These biosynthesized polypeptides have precise lengths and amino acid sequences. Transition temperatures were measured as a function of molecular weight and solution concentration and compared to their linear counterparts. Like their linear counterparts, the transition temperature is linearly related to log concentration. A mathematical relationship was used to fit the transition temperature data of different polypeptide lengths to a volume-based concentration using the polymer coil volume. The results of this model suggest that the linear ELP is in a random coil conformation at the transition temperature while the three-armed ELP is in a compact extended coil conformation, consistent with different pathways for aggregation. Solutions containing both trimer and linear constructs have two transition temperatures, further supporting differing aggregation behaviors.
authors.affiliation: Department of Chemical and Biomedical Engineering, Cleveland State University, Cleveland, Ohio 44115, United States.
authors.forename: Ali
authors.initials: A
authors.lastname: Ghoorchian
authors.forename: Nolan B
authors.initials: NB
authors.lastname: Holland
mesh_terms: D000465:Algorithms; D000595:Amino Acid Sequence; D004549:Elastin / Q000737:chemistry*; D008958:Models, Molecular; D009391:Nephelometry and Turbidimetry; D010455:Peptides / Q000737:chemistry*; D017510:Protein Folding; D055503:Protein Multimerization; D055550:Protein Stability; D020836:Protein Structure, Quaternary; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D044366:Transition Temperature
chemical_list: D010455:Peptides; D011994:Recombinant Proteins; D004549:Elastin