On the appearance of carboxylates in electrostatic potential maps

Protein Sci. 2017 Mar;26(3):396-402. doi: 10.1002/pro.3093. Epub 2016 Dec 26.


Electron microscopy can provide accurate, high-resolution images of the distribution of electrostatic potential (ESP) in biological macromolecules. Careful examination of ESP maps that have been published for peptides and proteins at resolution ranging from 1.0 Å to 2.9 Å reveals that the negative charges of carboxylate groups have a profound effect on their appearance. It is clear that investigators must take the negative features in their experimental ESP maps into account when modeling the conformations of Asp and Glu side chains and those of the residues that surround them.

Keywords: RSCC; electron microscopy; electron scattering; electrostatic potential; protein carboxylate side chain; real-space correlation coefficient.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aspartic Acid / chemistry*
  • Glutamic Acid / chemistry*
  • Models, Molecular*
  • Static Electricity


  • Aspartic Acid
  • Glutamic Acid

Associated data

  • PDB/5K12
  • PDB/5A1A
  • PDB/4TTG
  • PDB/4ZNN