pH-Induced Conformational Changes of liver basic Fatty Acid-Binding Protein (lb-FABP) bound to Lipid Membranes

MARÍA VERÓNICA NOLAN, MASSIMILIANO PERDUCA, HUGO MÓNACO, GUILLERMO MONTICH.

Bariloche

Congreso; Reunión Anual de la Sociedad de Biofísica; 2003

Sociedad Argentina de Biofísica

Understanding the interactions that fatty acid-binding proteins establish with lipid membranes is relevant to know the biological functions of these proteins and the mechanisms for fatty acids transport. We have previously shown that Lb-FABP interacts with anionic lipid membranes. As a consequence, the protein acquires the characteristics of a partially folded intermediate: it maintains some secondary structure and loose the native tertiary structure. It can be proposed that partial unfolding under these conditionms is facilitated both by the local decrease of pH in the proximity of the anionic membrane ann by direct interaction with lipids. To address this questionwe have studied the conformational change of Lb-FABP in solution and in the presence of anionic membranes using FT-IR and CD. It is concluded that the observed conformational change is not due to the acidic environment in the vecinity of the membrane but it is also mediated by direct interaction of the protein with lipid.