On the dielectric spectra of proteins in conducting media

✍ Scribed by Graciela Ruderman; Juan R. Xammar Oro

• Book ID: 104767024
• Publisher: Springer Netherlands
• Year: 1991
• Tongue: English
• Weight: 402 KB
• Volume: 18
• Category: Article
• ISSN: 0092-0606
• DOI: 10.1007/bf00417805

✦ Synopsis

The effect of conductivity on the dielectric measurements of proteins is studied. For that purpose the dielectric spectra (0.03-13 MHz) of serum albumin and myoglobin in solutions of varying conductivities were recorded. The results presented confirm that Maxwell's prediction of a threshold frequency in conducting materials also holds for protein solutions. The threshold frequency of a serum albumin solution is experimentally determined and the ionic screening of the electric field when performing dielectric spectra of these samples discussed. Three distinct frequency regions must be considered: a low frequency region where the sample behaves like a conductor; an intermediate region centered around the threshold frequency where the free charges partially screen the fixed charges; and a high frequency region where the sample behaves like a good dielectric. Dielectric measurements in the low frequency region defined above, are not possible.