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Effect of Solvent and Temperature on Secondary and Tertiary Structure of Zein by Circular Dichroism

May 2007 Volume 84 Number 3
Pages 265 — 270
Gordon W. Selling,1,2 Sharon A. H. Hamaker,1 and David J. Sessa1
Plant Polymer Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, 1815 N. University St., Peoria, IL 61604-3902. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standards of the product, and the use of the name by the USDA implies no approval of the product to the exclusion of others that may also be suitable.Corresponding author. E-mail: sellingg@ncaur.usda.gov


Go to Article:
http://dx.doi.org/10.1094/CCHEM-84-3-0265
Accepted January 16, 2007.
ABSTRACT

Circular dichroism studies were performed on zein to determine how the secondary and tertiary structure changes with different solvents, temperatures, or pH. Alcoholic solvent type and common denaturants such as SDS and low amounts of urea had little effect on the secondary structure of zein. Utilization of dimethylformamide or acetic acid as solvent gave changes in tertiary structure. Solutions of zein in 8M urea produced solutions with large changes in tertiary structure. The dissolution of zein in 50 mM sodium hydroxide produces a zein with large changes in secondary and tertiary structure and little loss in primary structure. Increasing the temperature of zein to 70°C in 80% ethanol-water gave reversible changes in the primary structure (20% reduction in absolute magnitude of [θ]λ at 208 and 222 nm) and tertiary structure (40% reduction in absolute magnitude of [θ]λ at 268 nm).


This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. AACC International, Inc., 2007.