Protonation states of buried histidine residues in human deoxyhemoglobin revealed by neutron crystallography

J Am Chem Soc. 2007 Dec 5;129(48):14840-1. doi: 10.1021/ja0749441. Epub 2007 Nov 9.

Abstract

The protonation states of buried histidine residues in human deoxyhemoglobin were unambiguously identified by using a neutron crystallographic technique. Unexpectedly, the neutron structure reveals that both the alpha- and beta-distal histidines (Hisalpha58 and Hisbeta63) adopt a positively charged, fully (doubly) protonated form, suggesting their contribution to the Bohr effect. In addition, the neutron data provide an accurate picture of the alpha1beta1 hydrogen-bonding network and allow us to observe unambiguously the nature of the intradimeric interactions at an atomic level.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Hemoglobins / chemistry*
  • Histidine / chemistry*
  • Humans
  • Models, Molecular
  • Neutron Diffraction
  • Protein Structure, Tertiary
  • Protons*

Substances

  • Hemoglobins
  • Protons
  • Histidine
  • deoxyhemoglobin