Observation of dielectric universalities in albumin, cytochrome C and Shewanella oneidensis MR-1 extracellular matrix

Sci Rep. 2017 Nov 16;7(1):15731. doi: 10.1038/s41598-017-15693-y.

Abstract

The electrodynamics of metals is well understood within the Drude conductivity model; properties of insulators and semiconductors are governed by a gap in the electronic states. But there is a great variety of disordered materials that do not fall in these categories and still respond to external field in an amazingly uniform manner. At radiofrequencies delocalized charges yield a frequency-independent conductivity σ 1(ν) whose magnitude exponentially decreases while cooling. With increasing frequency, dispersionless conductivity starts to reveal a power-law dependence σ 1(ν)∝ν s with s < 1 caused by hopping charge carriers. At low temperatures, such Universal Dielectric Response can cross over to another universal regime with nearly constant loss ε″∝σ1/ν = const. The powerful research potential based on such universalities is widely used in condensed matter physics. Here we study the broad-band (1-1012 Hz) dielectric response of Shewanella oneidensis MR-1 extracellular matrix, cytochrome C and serum albumin. Applying concepts of condensed matter physics, we identify transport mechanisms and a number of energy, time, frequency, spatial and temperature scales in these biological objects, which can provide us with deeper insight into the protein dynamics.

MeSH terms

  • Albumins / metabolism*
  • Animals
  • Cattle
  • Cytochromes c / metabolism*
  • Electric Conductivity
  • Electricity*
  • Extracellular Matrix / metabolism*
  • Shewanella / metabolism*
  • Spectrum Analysis
  • Temperature
  • Water / chemistry

Substances

  • Albumins
  • Water
  • Cytochromes c