Reinhold Benesch

Reinhold Benesch was a biochemist who investigated hemoglobin function in collaboration with Ruth E. Benesch. Their 1969 account of intracellular organic phosphates explained a mechanism by which 2,3-Bisphosphoglycerate changes oxygen affinity: the regulator binds preferentially to deoxyhemoglobin, making oxygen release more favourable at a specified oxygen partial pressure. This identifies a chemical regulator of oxygen transport, rather than treating hemoglobin affinity as an immutable property of the isolated protein.^[ref]

The discovery is an example of allostery: ligand binding at one part of a molecular system affects binding elsewhere. A short equilibrium argument shows why the effect is reciprocal. Consider an original four-state model with one oxygen ligand $O$ and one regulator $B$, allowing states $H$, $HO$, $HB$ and $HOB$. Define dissociation constantsMultiplying around the two possible binding paths givesThus, if regulator binding makes oxygen ten times harder to bind in this model, $K_{O\mid B}/K_O=10$, oxygen binding must likewise increase the regulator's dissociation constant tenfold. An equilibrium coupling cannot act in only one direction. The four-state construction is an illustrative reduction, not a claim that the four oxygen-binding subunits of real hemoglobin behave as one physical site.

This reasoning motivates a controlled measurement: compare oxygen-equilibrium curves for matched hemoglobin preparations with different regulator concentrations, while controlling pH, temperature and solution composition. Measuring regulator binding as well tests the reciprocal side of the proposed mechanism. His coauthored 1969 paper with Ruth E. Benesch and Chi Irg Yu explicitly examined how several of these conditions enter the oxygenation problem.^[ref]

The scientific contribution is collective in these sources. Their joint paper does not establish a separate personal allocation of the chemical preparation, measurements and interpretation. The photograph below is the institutionally identified joint image, credited to Columbia University's Department of Biochemistry.^[ref]