BIOC 3560 Lecture Notes - Lecture 4: Cooperative Binding, Myoglobin, Hemoglobin A

• School: University of Guelph
• Department: Biochemistry
• Course: BIOC 3560
• Professor: Manfred Brauer

Document Summary

In theory: hemoglobin has 4 binding sites, so, if nh was 4, this would mean all sites are simultaneously fully occupied and every single protein is completely saturated in solution (not common). 2 models for conversion of t and r states in cooperative binding. Conformation change in one subunit promotes conformational change in adjacent subunit. Jacques monod, jeffries wyman and jean-pierre changeux (1965) Subunits are functionally identical (all are t or all are r) Increased o2 binding to subunits in t state will encourage subunits to switch to r state (entire molecule does this conformation change simultaneously) Ligand binding can induce conformational change in subunits independently. The changes in quarternary structure of hb (t -> r transition) have dramatic effects on its function as an o2 binding protein. O2 binding curve of hb is diagnostic of cooperative binding. Cooperative binding requires: >1 ligand-binding site, interaction between ligand-binding sites.