AbstractA 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.