Toggle rotation around twofold rotation axis. Note how the Val 6B side chain projects into the solvent. Polymerization occurs when pairs of the deoxygenated HbS aggregate to form long fibers. Each pair is held together by a hydrophobic plug. This plug is formed by inserting the side chain of Val 6B of one partner of the pair into a hydrophobic socket in the opposite partner of the pair. Single beta chain; the side chains of Phe 85 and Leu 88 are exposed at the surface just below the heme group. This hydrophobic socket does not exist in oxygenated HbS. Toggle close-up of hydrophobic socket. Val 6B from the other member of the pair fits into this socket. Pairs of HbS molecules aggregate to form long fibers. Click on buttons below to cycle through various views of the unit pair: Two paired HbS molecules. Paired beta chains, one from each HbS molecule. Toggle alternate views of plug. Normal hemoglobin cannot aggregate in a pairwise fashion since close contact of the pairs would force the side chain of Glu 6B into the hydrophobic socket.
Single beta chain; the side chains of Phe 85 and Leu 88 are exposed at the surface just below the heme group. This hydrophobic socket does not exist in oxygenated HbS. Toggle close-up of hydrophobic socket. Val 6B from the other member of the pair fits into this socket. Pairs of HbS molecules aggregate to form long fibers. Click on buttons below to cycle through various views of the unit pair: Two paired HbS molecules. Paired beta chains, one from each HbS molecule. Toggle alternate views of plug. Normal hemoglobin cannot aggregate in a pairwise fashion since close contact of the pairs would force the side chain of Glu 6B into the hydrophobic socket.
Toggle close-up of hydrophobic socket. Val 6B from the other member of the pair fits into this socket. Pairs of HbS molecules aggregate to form long fibers. Click on buttons below to cycle through various views of the unit pair: Two paired HbS molecules. Paired beta chains, one from each HbS molecule. Toggle alternate views of plug. Normal hemoglobin cannot aggregate in a pairwise fashion since close contact of the pairs would force the side chain of Glu 6B into the hydrophobic socket.
Two paired HbS molecules. Paired beta chains, one from each HbS molecule. Toggle alternate views of plug. Normal hemoglobin cannot aggregate in a pairwise fashion since close contact of the pairs would force the side chain of Glu 6B into the hydrophobic socket.
Paired beta chains, one from each HbS molecule. Toggle alternate views of plug. Normal hemoglobin cannot aggregate in a pairwise fashion since close contact of the pairs would force the side chain of Glu 6B into the hydrophobic socket.
Toggle alternate views of plug. Normal hemoglobin cannot aggregate in a pairwise fashion since close contact of the pairs would force the side chain of Glu 6B into the hydrophobic socket.