Related Experiment Video
Updated: Aug 17, 2026

T-wave Ion Mobility-mass Spectrometry: Basic Experimental Procedures for Protein Complex Analysis
Published on: July 31, 2010
An allosteric theory for hemoglobin incorporating asymmetric states to test the putative molecular code for
1Département de Biochimie, Université de Genève, Switzerland.
Abstract:
The two-state (MWC) model for cooperative oxygen binding by tetrameric (alpha2beta2) hemoglobin based on concerted transitions between symmetric states (T and R) is extended to include a third, asymmetric state with one alphabeta dimer possessing high (R-like) oxygen affinity and the other alphabeta possessing low (T-like) oxygen affinity. The asymmetric state is assigned a stability that corresponds to the level reported by Ackers and colleagues in the studies on mixed valence hybrids that led to their proposed "molecular code for cooperativity in hemoglobin." However, this level of stability for the asymmetric intermediates significantly diminishes cooperativity in simulated oxygenation curves, to a degree (Hill n = 2.1) that is no longer compatible with the well-established oxygenation properties of normal ferrous hemoglobin (Hill n approximately 3.0). Therefore, the cyanomet derivatives do not appear to be reliable analogues of intermediate oxygenation states.
Related Concept Videos
Allosteric Regulation
Allosteric Regulation
Cooperative Allosteric Transitions
Cooperative Allosteric Transitions
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Cooperative Allosteric Transitions

