Microwave Absorption in a Helical Polypeptide Molecule

Abstract

Microwave absorption measurements (3, 8.5, 36 and 72 GHz) arc reported on three different molecular weight samples of polyCy-bcnzyl-L-glutamatc), PBLG, in two solvents. In each case a distinct absorption, often quite narrow (the Fuoss-Kirkwood parameter (3 ~ 1.0), which is almost temperature independent is centred between 2 and 15 GHz. Its frequency, intensity and contour arc not inconsistent with a helical-spring mode suggested to account for the abnormal increase in (x|| -a1) between the visible and 6 MHz. Other possible origins are considered.