Stabilizing salt bridges of the β1/β2 interface in guinea pig hemoglobin.

<p>The β1/β2-interface of guinea pig hemoglobin in the R2-state is stabilized by two salt bridges between the N-terminal amino group of Val1 the β1-subunit and the C-terminal carboxyl group of the β2-subunit and vice versa. Both salt bridges are not present in the R2-state of human hemoglobin (1BBB)<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0012389#pone.0012389-Silva1" target="_blank">[10]</a>. Guinea pig hemoglobin (β1 = red, β2 = light red) and human hemoglobin (β1 = blue, β2 = light blue) in the R2-state (PDB-code: 1BBB) were superimposed according to their C_α-atoms. Carbon atoms of the N- and C-terminal amino acids of guinea pig hemoglobin are colored light red, while carbon atoms are colored blue in human hemoglobin. Oxygen and nitrogen atoms are colored red and blue respectively. Salt bridges are denoted by dotted lines.