Biology Reference
In-Depth Information
38
Figure 2-1.
The heme.
extensively by numerous famous biochemists and molecular biologists over
the years. In this chapter, we are going to review the known biological facts
about these two proteins and discuss three models of saturation of
hemoglobin with oxygen at equilibrium.
STRUCTURES OF MYOGLOBIN AND HEMOGLOBIN
Perutz has reviewed the structures of myoglobin and hemoglobin in 1962,
and, with his collaborators, the cooperative effects of hemoglobin in 1998.
His life time contribution to the understanding of these proteins, especially
hemoglobin, is monumental. The amino acid sequences of sperm whale
myoglobin (Mb) and and subunits of human hemoglobin (Hb) are
aligned in Table 2-1 (Perutz, 1962), relative to the locations of the helices A
through H (Nobbs
et al
., 1966). The three dimensional structure of
myoglobin had been determined before its amino acid sequence was
completely characterized. Furthermore, some of the amino acid residues
were not visible in the three dimensional structure due to the flexibility of
loops connecting helices.
