In sickle cell anaemia, sickle shapes occur due to polymerization of: (A) Oxyhemoglobin, (B) Deoxyhemoglobin, (C) Methoxyglobin, (D) Cyanohemoglobin
Answer is B. The substitution of hydrophilic glutamic acid by hydrophobic valine causes a localized stickiness on the surface of the molecule. The deoxygenated HbS may be depicted with a protrusion on one side and a cavity on the other side, so that many molecules can adhere and polymerize.Ref: D M Vasudevan 7th edition Page no: 291,292