Non‐newtonian viscosity of polypeptides in the helix–coil transition region

Abstract

AbstractThe non‐Newtonian intrinsic viscosities [η] of poly(γ‐methyl L‐glutamate) were measured in the helix–coil transition region under various conditions in this work. The helix content fH, which represents the degree of conformational transition, was obtained by using a polarimeter. Our experimental results show that the non‐Newtonian behavior of the polypeptide is markedly affected by its conformation; i.e., the non‐Newtonian effect becomes larger as fH increases. The effect of external pressure ΔP on [η] was studied carefully; [η] increases with fH when ΔP < 1.5 psi, but it decreases when ΔP > 1.5 psi and fH > 0.8. The reason for this result is considered in the text.