Question

Which of the following statements best describes how 2,3-bisphosphoglycerate (2,3-BPG) reduces hemoglobin's affinity for oxygen?

		2,3-BPG binds to the heme iron and prevents oxygen from binding.
		2,3-BPG binds to positively charged Lys and His residues in the center of the hemoglobin, stabilizing the T (low-affinity) state.
		2,3-BPG binds to the amino termini and stabilizes the R state.
		2,3-BPG binds to the α1β1-α2β2 interface and stabilizes the R state.

Answer 1

Ans : 2,3-BPG binds to positively charged Lys and His residues in the center of the hemoglobin , stabilising the T (low affinity) state.

Usually the R (relaxed ) state if hemoglobin is more stable than the T(tensed ) state. 2,3-BPG binds to the center of the tetramer of the hemoglobin molecule and stabilises its T state. Due to this hemoglobin is unable to bind oxygen and much of the oxygen can be given to the tissues. This is particularly helpful in the people that live in high altitude regions.