My research project for this summer will be to analyze various elastin-like polypeptides (ELPs). ELPs are polypeptides that incorporate the 5 amino acid long sequence of Val-Pro-Gly-Xaa-Gly, where Xaa represents an unspecific amino acid. ELPs are a kind of artificial intrinsically disordered protein (IDP), which are proteins that do not fold in the typical way but rather maintain an unfolded (disordered) form that permits multivalent behavior. ELPs also change phase with lower critical solution temperature behavior, which means that they will be soluble below a critical temperature and phase separate at/above it.
So far, I have worked on cloning recombinant plasmids that contain part of the desired ELP sequence with E. coli. Each ELP sequence has an “A cut” and a “B cut” plasmid which will be ligated together in order to get the desired sequence. This is done because ELP sequences are quite repetitive and this makes it difficult for manufacturers to directly make it. E. coli is also used in order to generate the protein from the plasmid. Flasks of E. coli are given the plasmid and reproduce until they almost reach carrying capacity, at which point they are given a treatment to induce protein synthesis. This is done in order to maximize yield as a flask well below carrying capacity would not be able to produce as much protein and one at carrying capacity would not be as metabolically active.
