text: Elastin-like polypeptides (ELPs) are synthetic biopolymers with potential applications in the fields of cancer therapy, tissue scaffolding, metal recovery, and protein purification.  For cancer therapy, the addition of functional groups to ELPs can enable them to conjugate with cytotoxic drugs.  Also, ELPs may be able to function as polymeric scaffolds, which promote tissue regeneration.  This capacity of ELPs has been studied particularly in the context of bone growth. ELPs can also be engineered to recognize specific proteins in solution. The ability of ELPs to undergo morphological changes at certain temperatures enables specific proteins that are bound to the ELPs to be separated out from the rest of the solution via experimental techniques such as centrifugation.
  The general structure of polymeric ELPs is (VPGXG), where the monomeric unit is Val-Pro-Gly-X-Gly, and the "X" denotes a variable amino acid that can have consequences on the general properties of the ELP, such as the transition temperature (T). Specifically, the hydrophilicity or hydrophobicity and the presence or absence of a charge on the guest residue play a great role in determining the T Also, the solubilization of the guest residue can effect the T The "n" denotes the number of monomeric units that comprise the polymer. In general, these polymers are linear below the T, but aggregate into spherical clumps above the T.