A model of human APOA2 on HDL.
Level 5 - mechanism / opinion, no new human data
Mechanistic structural modeling and in vitro bench study without human clinical data.
PubMed 42508573 · doi:10.1016/j.jlr.2026.101113
What was done
The authors developed a structural model for lipid-bound human apolipoprotein A-II (APOA2) on discoidal high-density lipoprotein (HDL) particles using computer modeling and mutagenesis. The proposed structural model was experimentally evaluated using chemical cross-linking and tandem mass spectrometry (MS/MS).
What was found
The structural model indicates that APOA2 forms a belt-like configuration restricted by its single disulfide bond, stabilized by salt bridges and pi-pi interactions, with basic residues positioned in the hairpin loop and two high-lipid affinity helical regions per monomer. Chemical cross-linking and MS/MS identified 16 cross-links, 15 of which were consistent with the double hairpin belt model.
Why it matters
This work provides a molecular-level structural model of how APOA2 organizes on discoidal HDL particles, clarifying its lipid interactions and structural role in HDL maturation.
Limits
This is an in silico and in vitro biophysical study with no in vivo or human clinical outcome measurements. One of the 16 cross-links did not fit the proposed double hairpin belt model, and sample sizes or replicate numbers are not reported in the abstract.
Cited by
- supports ApoA apolipoproteins wrap the high-density lipoprotein (HDL) family of particles.