Page 290 - Color Atlas of Biochemistry

Blood 281

A. Hemoglobin: structure

NH NH Proximal Distal
β 3 3 β histidine O 2 histidine
COO
A E F
H

B G C D
G B
H
D C E

F A
α α

NH 3 COO
F helix Heme E helix
Hemoglobin A (α β ) M: 65 kDa
2
2
B. Hemoglobin: allosteric effects

pO 2
pCO , pH
2
[BPG]

4 O 2 Hb · BPG Hb · (O ) H BPG
R
2 4
T
T R
pO 2
pCO 2 , pH
[BPG]

α α
α α

β β β β
O 2 bond
BPG weakens
stabilizes association
T form O 2 affinity 70
times higher
than in T form
Deoxyhemoglobin Oxyhemoglobin
T form R form

Koolman, Color Atlas of Biochemistry, 2nd edition © 2005 Thieme
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