Apolipoprotein A-I structure and lipid properties in homogeneous, reconstituted spherical and discoidal high density lipoproteins.

摘要: We prepared a spherical reconstituted high density lipoprotein (rHDL) particle in pure form and compared it with its homogeneous discoidal rHDL precursors, terms of the structure stability apolipoprotein A-I (apoA-I) component, dynamics surface lipids, relative reactivity lecithin-cholesterol acyltransferase. The apoA-I-structure was examined particles by circular dichroism fluorescence spectroscopic methods, binding monoclonal antibodies specific for apoA-I epitopes. on assessed effects guanidine hydrochloride wavelength maximum intrinsic apolipoprotein. Lipid acyl chain region polarity lipid-water interface were investigated means probes. conformation 93-A found to be very similar that 96-A discs but distinct from 78-A discs. denaturation highest spheres. experiments lipids indicate somewhat more ordered motionally restricted chains spheres, discs, polarity. These results suggest folding organization three include protein domains consisting interacting alpha-helical segments carboxyl-terminal globular domain amino-terminal each molecule. acyltransferase disc, 16- 34-fold lower disc sphere, respectively, possibly as result differences product inhibition these particles.