Muscle fatty acid-binding protein.

Area of Science:

• Biochemistry
• Structural Biology
• Molecular Biology

Background:

• Fatty acid-binding proteins (FABPs) are crucial for intracellular fatty acid transport.
• Muscle and heart FABPs bind long-chain fatty acids in the cytosol.
• Known three-dimensional structures of human, bovine, and insect FABPs provide a basis for understanding their function.

Purpose of the Study:

• To elucidate the molecular mechanisms underlying fatty acid binding specificity in FABPs.
• To investigate the structural basis for fatty acid accommodation and stabilization within the protein interior.

Main Methods:

• X-ray crystallography and Nuclear Magnetic Resonance (NMR) techniques were used to determine protein structures.
• Molecular dynamics simulations were employed to analyze protein-ligand interactions.
• Analysis of electrostatic, hydrogen bond, and hydrophobic interactions was performed.

Main Results:

• The conserved FABP fold consists of ten anti-parallel beta-strands forming a "clam shell" structure, enclosing an internal cavity.
• The internal cavity accommodates and protects the bound fatty acid.
• Interactions between the fatty acid's carboxyl head and polar/charged protein residues, and its tail with hydrophobic residues, stabilize the complex.

Conclusions:

• The structural arrangement of FABPs facilitates specific fatty acid binding.
• Molecular dynamics simulations offer detailed insights into the specificity of ligand binding.
• Understanding FABP structure-ligand interactions is key to elucidating their physiological roles.