Nolan Verónica, Perduca Massimiliano, Monaco Hugo L, Maggio Bruno, Montich Guillermo G
Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba CIQUIBIC (CONICET)-Pabellón Argentina, Ciudad Universitaria Córdoba (5000), Argentina.
Biochim Biophys Acta. 2003 Apr 1;1611(1-2):98-106. doi: 10.1016/s0005-2736(03)00030-0.
The interactions of chicken liver basic fatty acid-binding protein (Lb-FABP) with large unilamellar vesicles (LUVs) of palmitoyloleoyl phosphatidylcholine (POPC) and palmitoyloleoyl phosphatidylglycerol (POPG) were studied by binding assays, Fourier transform infrared (FT-IR) spectroscopy, monolayers at air-water interface, and low-angle X-ray diffraction. Lb-FABP binds to POPG LUVs at low ionic strength but not at 0.1 M NaCl. The infrared (IR) spectra of the POPG membrane-bound protein showed a decrease of the band corresponding to beta-structures as compared to the protein in solution. In addition, a cooperative decrease of the beta-edge band above 70 degrees C in solution was also evident, while the transition was less cooperative and took place at lower temperature for the POPG membrane-bound protein. Low- and wide-angle X-ray diffraction experiments with lipid multilayers indicate that binding of the protein produces a rearrangement of the membrane structure, increasing the interlamellar spacing and decreasing the compactness of the lipids.
