The helical content of zein, a water insoluble protein, in non-aqueous solvents.

The conformation of zein, a seed protein from corn, was determined by optical rotary dispersion measurements in a wide variety of nonaqueous solvents. Over a wide range of dielectric constants, in pure and mixed solvent systems, the helical content was independent of dielectric constant. Determination of the helical content of insulin and ribonuclease in several of these solvents indicated a variation in secondary structure comparable of that of zein. Though virtually insoluble in water, zein not only is a globular protein in nonaqueous solutions, but has conformational properites characteristic of more conventionally behaving globular proteins.