A novel lipid-binding protein from the cestode Moniezia expansa

Area of Science:

• Biochemistry
• Parasitology
• Molecular Biology

Background:

• Lipid-binding proteins (LBPs) are crucial for cellular lipid transport and metabolism.
• Fatty acid-binding proteins (FABPs) are a well-characterized class of LBPs.
• The functional roles of LBPs in parasitic helminths remain largely unexplored.

Purpose of the Study:

• To purify and characterize a novel lipid-binding protein from the cestode Moniezia expansa.
• To investigate the ligand-binding specificities and structural properties of the Moniezia LBP.
• To explore the potential role of this LBP in anthelmintic drug action.

Main Methods:

• Protein purification from cestode cytosol.
• Ligand-binding assays using various fatty acids, sterols, and other molecules.
• Spectroscopic techniques (CD) and urea denaturation for structural analysis.
• Antibody cross-reactivity tests with other FABPs.
• Amino acid sequencing.

Main Results:

• Purified Moniezia LBP is a 250 kDa oligomer of 11 kDa monomers.
• The protein binds saturated/unsaturated fatty acids, cholesterol, bilirubin, and retinoids, with distinct specificities.
• It exhibits unique amino acid composition and sequence, unrelated to known FABPs.
• Moniezia LBP binds a range of anthelmintics with high affinity.
• Ligand binding causes minimal changes in protein secondary structure.

Conclusions:

• Moniezia LBP represents a novel class of lipid-binding protein in helminths.
• Its broad ligand-binding capacity, including anthelmintics, suggests a significant physiological role.
• This protein may influence the specificity and mechanism of action of antiparasitic drugs.