Related Experiment Videos
Echinococcus granulosus antigen B hydrophobic ligand binding properties
Gustavo Chemale1, Henrique B Ferreira, John Barrett
1Centro de Biotecnologia and Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Caixa Postal 15005, Porto Alegre, RS, 91501-970, Brazil.
Biochimica Et Biophysica Acta
|February 9, 2005
Summary
Echinococcus granulosus Antigen B (AgB) binds fatty acids differently than similar proteins, suggesting unique functions in cestode environments. This study characterized AgB
Area of Science:
- Parasitology
- Biochemistry
- Molecular Biology
Background:
- Antigen B (AgB) is a major component of the cestode parasite Echinococcus granulosus.
- AgB shares structural similarities with helix-rich hydrophobic ligand binding proteins (HLBPs) found in other cestodes.
Purpose of the Study:
- To investigate the fatty acid binding properties of Echinococcus granulosus Antigen B (AgB).
- To compare the binding characteristics of native and recombinant AgB subunits with various fluorescent fatty acid analogs.
Main Methods:
- Purification of native AgB from hydatid cyst fluid via affinity chromatography.
- Expression and purification of recombinant AgB subunits (rAgB8/1 and rAgB8/2) in E. coli.
- Fluorescence-based binding assays using ligands like 16-AP, DAUDA, ANS, and DACA.
Main Results:
- The palmitic acid-derived ligand 16-AP showed the strongest fluorescence enhancement upon binding to native and recombinant AgB.
- Dissociation constants for 16-AP binding to AgB were determined.
- Unlike other HLBPs, AgB exhibited increased fluorescence with other fatty acids, indicating a distinct binding mechanism.
Conclusions:
- AgB demonstrates unique hydrophobic compound binding properties compared to homologous proteins in other cestodes.
- These findings suggest AgB may have evolved specialized functions in binding hydrophobic molecules, adapted to its specific cestode environment.