Allosteric transitions of proteins studied by topological networks: a preliminary investigation on human hemoglobin.

Abstract

A concise description of the 3D structure of a and b chains of human haemoglobin, as well as of ab dimers, is provided for both the R and T forms on the basis of topological network parameters. Such parameters are able to account for the allosteric conformational transitions as derived by standard 3D pictures and models in the literature. In particular, the difference between the R and T forms appears more relevant in the case of dimers, in agreement with the idea that dimers are essential in the allosteric mechanism of Hb as an oxygen carrier.This result encourages the extension of the network-based, topological representation of protein structures to less overexploited systems than Hb, as well as to the vast realm of data coming from resonance spectroscopy.