Allosteric Regulation of the M2 Protein from Influenza A by Cholesterol

Abstract

Protein structure and function aremodulated by the interactions withtheir environment (1). For membraneproteins, the environment is repre-sented by both the bulk water and lipidmembranes that have an active role inshaping their structural topology. Inthe 1970s, Fari´as et al. (2) hypothe-sized that lipid membranes may influ-ence enzyme cooperativity throughallosteric changes. These authorsshowed that membrane compositionand fluidity deeply affect ATPase ac-tivity. Hill coefficients for these en-zymes were also correlated with thechanges in the lipid uptake caused bythe dietary regime of the animalsources. Indeed, different membranecompositions are able to activate ordeactivate large membrane proteincomplexes such as Ca