(4 of 5) Hemoglobin is known to exist in both T- and R-state conformations. The
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(4 of 5) Hemoglobin is known to exist in both T- and R-state conformations. The T-state is stabilized by a significant number of noncovalent interactions many of which are concentrated within the C-terminus of both subunits an are not observed in the R-state. Given this information which of the following statements is true? OFor a T- to R-state transition to occur a significant enthalpic cost must be paid. O Replacement of these noncovalent interactions with disulfide bonds would likely lead to a hemoglobin molecule with a much smaller P50 for oxygen. O The negative charge of BPG (bis-phosphoglycerate) leads to electrostatic repulsion at the c-terminus of each subunit leading to a smaller P50 for hemoglobin. O The pH is not expected to have any effect on these noncovalent interactions. O All of the above.Explanation / Answer
The true statement is - For a T- to R-state transition to occur a significant enthalpic cost must be paid.
T to R transition is due to destabilization of bonds at the C-terminus. There is a small movement in the FG group that leads to a movement which leads to this destabilization leading to T to R transition.
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