[Mechanical properties of globular proteins]

The purpose of this paper is to present a new approach to the study of mechanical properties of globular proteins and to summarize some of our results. The approach is based on the analysis of mechanical, viscoelastic properties of a protein monocrystal which is used as a probe of mechanical properties of a protein molecule. As a first rough approximation a protein molecule can be considered as a material resembling molecular crystals and glass-like polymers with the Young's modulus E = 2 - 10 GN . m-2. More detailed information concerning the anisotropy of elasticity and that of inhibitor effect strongly suggests that the lysozyme molecule is a construction having a special hinge-bending degree of freedom. The force constant estimated from our data for this degree of freedom is (0,4-1) . 10(13) erg . rad-2 . mol-1.