Myoglobin distal histidine

Figure Bl.2.11. Biologically active centre in myoglobin or one of the subunits of haemoglobin. The bound CO molecule as well as the proximal and distal histidines are shown m addition to the protohaeme unit. From Rousseau D L and Friedman J M 1988 Biological Applications of Raman Spectroscopy vol 3, ed T G Spiro (New York Wiley). Reprinted by pennission of John Wiley and Sons Inc.

Fig. 3.2 The structure of myoglobin (deoxy form, PDB entry 1AGN, at 1.15 A resolution [3f]). The heme active center is highlighted (van der Waals spheres), as are the proximal and distal histidines (His93 and His64, respectively, shown as sticks).

There is no counterpart to the distal histidine of myoglobin in hemoglobin. 

Figure 16-10 Geometry of bonding of 02 to myoglobin and position of hydrogen bond to NE of the distal histidine E7 side chain. After Perutz.182...

Scheme 2.6.1. The role of the distal histidine (His64) in the isomerization of peroxynitrite bound to the iron (111) center of myoglobin.

Matsui T, Ozaki S, Liong E, Phillips GN, Watanabe Y (1999) Effects of the location of distal histidine in the reaction of myoglobin with hydrogen peroxide. J Biol Chem 274 2838-2844... 

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