Hemoglobin and 2,3-BPG !

Hemoglobin carries oxygen in the blood; 2,3-BPG, made by a side branch of red-cell glycolysis, helps it let go in the tissues.

Updated 2026-10-31

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Key facts

An α₂β₂ tetramer (HbA) with one heme (Fe²⁺) per chain: up to four O₂.
2,3-BPG binds the central cavity between the β chains of deoxyhemoglobin and stabilises the T state: the curve shifts right.
Bisphosphoglycerate mutase makes it from 1,3-BPG (the Rapoport–Luebering shunt), at the cost of one ATP.

Fetal hemoglobin (α₂γ₂) binds 2,3-BPG poorly, which is why it takes oxygen from the mother's blood.

Pyruvate kinase deficiency: high 2,3-BPG, better oxygen delivery. Hexokinase deficiency: low 2,3-BPG, worse anemia tolerance.
In Bogotá (2,600 m), adapting to altitude includes more 2,3-BPG and more hemoglobin.

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Which way does 2,3-BPG shift the hemoglobin dissociation curve?

To the right: it lowers oxygen affinity and helps release it in the tissues.

Why does fetal hemoglobin have higher oxygen affinity?

Its γ chains bind 2,3-BPG poorly.

Which enzyme makes 2,3-BPG in red cells?

Bisphosphoglycerate mutase, from 1,3-bisphosphoglycerate.

Educational information, not medical advice. For any symptom, see a health professional.

Sources: HBB: Hemoglobin subunit beta (human) (UniProt, 2026); 1B86: Human deoxyhaemoglobin-2,3-diphosphoglycerate complex (RCSB Protein Data Bank, 2026); 2,3-Bisphosphoglyceric acid (CID 61) (PubChem, NCBI, 2026) · Public domain; Textbook of Biochemistry for Medical Students, 6th ed. (Jaypee Brothers Medical Publishers (Vasudevan DM, Sreekumari S, Vaidyanathan K), 2011).

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