Poly(ethylene glycol) (PEG) Modifications and Conformational Analysis of Thymosin α 1

Results and Discussion According to the SAR results [1], the conjugating sites of Tα1 with PEG were chosen at the N-terminus, C-terminus, α-helix, β-turn, and the random coil regions. Referring to the method reported by Vanwetsswinkel et al [2,3], [Cys]Tα1 analogs (x: the chosen site) were synthesized firstly for conveniently introducing the covalent attachment mPEG-MAL into the chosen sites, and then the PEG conjugations were prepared as follows (Scheme 1) .