Interactions of chicken liver basic fatty acid-binding protein with lipid membranes.
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.
Nolan
Verónica
V
Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba CIQUIBIC (CONICET)-Pabellón Argentina, Ciudad Universitaria Córdoba (5000), Argentina.
Perduca
Massimiliano
M
Monaco
Hugo L
HL
Maggio
Bruno
B
Montich
Guillermo G
GG
D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002645:Chickens; D050556:Fatty Acid-Binding Proteins; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism*; D008099:Liver / Q000737:chemistry / Q000378:metabolism*; D009363:Neoplasm Proteins; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D011487:Protein Conformation; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014961:X-Ray Diffraction
D002352:Carrier Proteins; D050556:Fatty Acid-Binding Proteins; D008051:Lipid Bilayers; D009363:Neoplasm Proteins; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; C060037:1-palmitoyl-2-oleoylglycero-3-phosphoglycerol; C028694:1-palmitoyl-2-oleoylphosphatidylcholine