(PEO)2 is conjugated to(Asp)50. In neutral to alkaline solution, the peptide carboxlic acid side-chains of (Asp)50 are deprotonated and negatively charged, making the entire co-polymer unstructured, highly soluble and very hydrophilic. However, when the solution is acidified to pH < 4, the (Asp)50 loses its negative charge, and collapses into a rigid and hydrophobic α-helix. The result is a large molecule with a hydrophilic (PEO)2 end, and a hydrophobic peptide end (a surfactant.)
Design a reaction scheme to produce a PEO-S-S-(Asp)50 conjugate as described above.