Syntehsis and structural stability of helichrome as an artificial hemeproteins

Abstract
A detailed procedure is described for the syntehsis of helichrome, which is the first successful example of polypeptide-based artificial hemeprotein. The segment synthesis-condensation approach used for the assembly of small proteins has proven to be extremely useful for protein mimetics as well. The final deprotection was performed using the TNSOTf-thioanisole method instead of the less-convenient hydrogen fluoride method. The unfolding transition of the α-helical conformation of helichrome induced by guanidine hydrochloride was studied to understand the stability and dynamics of the folded structure. The resulting parameters (C0.5 = 5.2M and ΔGH2O = −4.4 kcal mol−1) characterizing helichrome denaturation were comparable to that of native globular proteins.