Influence of N-terminal helix bundle stability on the lipid-binding properties of human apolipoprotein A-I

►S55P mutation had a modest effect on the stability of the bundle structure of apoA-I. ►S55P/Δ190-243 apoA-I restored the lipid binding despite the C-terminal truncation. ►Destabilized N-terminal helix bundle promoted lipid solubilization. ►Alterations in the stability of apoA-I appear to influence the production of HDL.