Theoretical model of human apolipoprotein B100 tertiary structure

Area of Science:

• Biochemistry
• Structural Biology
• Lipid Metabolism

Background:

• Low-density lipoprotein (LDL) particles are primary plasma cholesterol carriers.
• The complex structure of apolipoprotein B100 (apoB), stabilizing LDL, remains largely unknown.
• Previous work proposed a 3D model for the N-terminal region of apoB.

Purpose of the Study:

• To develop the first tentative 3D models for the majority of apolipoprotein B100 (apoB) residues.
• To predict and analyze the structural features and functional roles of apoB within LDL particles.
• To propose a comprehensive model for apoB organization on the LDL particle.

Main Methods:

• Decomposition of apoB into eight domains using various prediction methods.
• 3D structure prediction for each apoB domain.
• Analysis of predicted hydrophobic/polar regions and functional predictions.

Main Results:

• Successful prediction of 3D structures for most apoB residues, organized into eight domains.
• Identification of putative lipid-interaction regions within the apoB structure.
• A proposed overall shape of apoB consistent with low-resolution electron microscopy data.

Conclusions:

• The developed 3D models offer new insights into the functional role of apoB.
• Specific regions of apoB are suggested to be involved in lipid interactions.
• The proposed apoB organization provides a plausible model for its structure on LDL particles.