Local/bulk determinants of conformational stability of exchangeable apolipoproteins.

摘要: Abstract GuHCl-induced denaturation of human plasma apoA-I, apoA-II, apoA-IV, apoE3 and three recombinant apoE isoforms in solution discoidal complexes with phosphatidylcholine (only proteins) was studied. The protein conformational stability (Δ G (H 2 O)) a slope linear dependence free energy unfolding on GuHCl concentration ( m -value) were estimated the equilibrium schemes. data for all proteins, except fit three-state model, thus evidencing two-domain structure. predicted folding rate four correlated stability. disappeared at inclusion apoA-I apoA-IV into analysis -values, adjusted residue number helices rh ), differed between those apoA-I/apoA-IV. However, -values six proteins positively fractional change accessible surface area Phe, Lys Asn, while negatively Arg, Ala Gly residues. difference Δ O) values apolipoproteins decreased increase reduced temperature T obs  −  t )/ . induction intrinsic disorder by arginine residues may be primary importance metabolism function exchangeable apolipoproteins, their nascent HDL is controlled physical state phosphatidylcholine.