A simple apparatus for generating stretched polyacrylamide gels, yielding uniform alignment of proteins and detergent micelles

J Biomol NMR. 2001 Dec;21(4):377-82. doi: 10.1023/a:1013336502594.

Abstract

Compressed and stretched polyacrylamide hydrogels previously have been shown to offer a robust method for aligning proteins. A simple, funnel-like apparatus is described for generating uniformly stretched hydrogels. For prolate-shaped proteins, gels stretched in the direction of the magnetic field yield two-fold larger alignment than gels compressed to the same aspect ratio in this direction. Empirically, protein alignment is found to be proportional to (c-2.3)2 [(d(o/dN)3-1], where do and dN are the diameters of the cylindrical gels before and after stretching, respectively, and c is the polyacrylamide weight fraction in percent. Low gel densities, in the 4-7% range, are found to have minimal effects on macromolecular rotational correlation times, tauc, and no effect of the compression ratio on tauc could be discerned over the range studied (do/dN < or = 1.4). Application is demonstrated for a sample containing the first Ig-binding domain of protein G, and for a detergent-solubilized peptide.

MeSH terms

  • Acrylic Resins / chemistry*
  • Detergents / chemistry*
  • Hydrogels / chemistry
  • Micelles
  • Nerve Tissue Proteins / chemistry
  • Nuclear Magnetic Resonance, Biomolecular / instrumentation*
  • Peptides / chemistry
  • Protein Binding
  • Protein Structure, Tertiary
  • Proteins / chemistry*
  • Proteins / metabolism

Substances

  • Acrylic Resins
  • Detergents
  • G-substrate
  • Hydrogels
  • Micelles
  • Nerve Tissue Proteins
  • Peptides
  • Proteins
  • polyacrylamide gels