A CONFORMATIONAL STUDY OF AGAROSE BY VACUUM UV CD

Agarose films were prepared using a variety of casting conditions, hea t treatments, and solvation treatments. Films represented the high tem perature sol, the room temperature gel, and a high temperature state w ith cross-links intact. The vacuum uv CD of the film samples varies co nsiderably, but the similarities between the film CD and the previousl y reported solution CD show that dehydration per se does not affect th e CD. Combining the CD results for the dried sol with the x-ray result s of Foord and Atkins leads to a description of the high temperature s ol in terms of locally extended chain conformations. The CD of the gel and its peculiarly high uv absorption are satisfactorily, albeit not uniquely, interpreted in terms of the double-helix model of the gel, i n agreement with previous conformational studies based on chiroptical properties. (C) 1994 John Wiley and Sons, Inc.