Crystal structure of hemoglobin from mouse (Mus musculus) compared with those from other small animals and humans

Abstract

Mice (Mus musculus) are nocturnal small animals belonging to the rodent family that live in burrows, an environment in which significantly high CO2 levels prevail. It is expected that mouse hemoglobin (Hb) plays an important role in their adaptation to living in such a high-CO2 environment, while many other species cannot. In the present study, mouse Hb was purified and crystallized at a physiological pH of 7 in the orthorhombic space group P212121; the crystals diffracted to 2.8 Å resolution. The primary amino-acid sequence and crystal structure of mouse Hb were compared with those of mammalian Hbs in order to investigate the structure–function relationship of mouse Hb. Differences were observed from guinea pig Hb in terms of amino-acid sequence and from cat Hb in overall structure (in terms of r.m.s.d.). The difference in r.m.s.d. from cat Hb may be due to the existence of the molecule in a conformation other than the R-state. Analysis of tertiary- and quaternary-structural features, the α1β2 interface region and the heme environment without any ligands in all four heme groups showed that mouse methemoglobin is in an intermediate state between the R-state and the T-state that is much closer to the R-state conformation.

Structural studies of hemoglobin from two flightless birds, ostrich and turkey: insights into their differing oxygen-binding properties

“…The ostrich and turkey Hbs were purified using the procedures described by Sundaresan et al (2009Sundaresan et al ( , 2021 and Ramesh et al (2013), respectively. Briefly, 5 ml fresh whole blood (WB) from ostrich and turkey was collected in separate tubes and subsequently mixed with 0.2 M EDTA to avoid clotting.…”

X-ray crystallography and sickle cell disease drug discovery—a tribute to Donald Abraham

“…Earlier computer program refinements of Hb structures were done in real space using Diamond’s method ( Fermi, 1975 ; Ladner et al, 1977 ; Baldwin and Chothia, 1979 ). Since these early published Hb structures, and with improvement in data collection, computation and crystallographic softwares, there has been an exponential increase in the number of solved Hb structures, including those from human (with or without allosteric effectors), and non-human, e.g., cat, bovine, fish, pig, bar-headed goose, plants, nematodes, etc ., ( Harutyunyan et al, 1995 ; Knapp et al, 1999 ; Mueser et al, 2000 ; Kidd et al, 2001 ; Safo and Abraham, 2001 ; Sundaresan et al, 2021 ). Several Hb variants have also been determined by X-ray crystallography ( Smith et al, 1991 ; Kavanaugh et al, 1992 ; Kavanaugh et al, 1998 ; Vasseur et al, 1992 ; Pechik et al, 1996 ; Harrington et al, 1997 ; Vásquez et al, 1998 ; Tame and Vallone, 2000 ; Abdulmalik et al, 2004 ; Ahmed et al, 2020 ).…”