Protonation states of buried histidine residues in human deoxyhemoglobin revealed by neutron crystallography.
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.
Chatake
Toshiyuki
T
Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494, Japan.
Shibayama
Naoya
N
Park
Sam-Yong
SY
Kurihara
Kazuo
K
Tamada
Taro
T
Tanaka
Ichiro
I
Niimura
Nobuo
N
Kuroki
Ryota
R
Morimoto
Yukio
Y
D006454:Hemoglobins / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D006801:Humans; D008958:Models, Molecular; D033363:Neutron Diffraction; D017434:Protein Structure, Tertiary; D011522:Protons
D006454:Hemoglobins; D011522:Protons; D006639:Histidine; C100003:deoxyhemoglobin