The amino acid substitution of Val for Glu in Hemoglobin S results in aggregation of the protein because of ___________ interactions between molecules.

Step-by-step solution

The amino acid substitution of Val for Glu in Hemoglobin S results in aggregation of abnormal hemoglobin because the hemoglobin becomes less soluble. The decreased oxygen concentration makes the hemoblobin to polymerize into crystals and this distorts the red blood cells into sickle shape. Replacing the amino acid glutamic acid with the less polar amino acid valine at the sixth position of the beta-chain favors a hydrophobic interaction in the hemoglobin.