Acyl-CoA Binding Protein (ACBP) also Binds Fatty Acids

Abstract

<p>The Acyl-CoA binding protein (ACBP) has been found to be an essential protein and is needed for many cellular processes. Although previous work suggested that the ACBP only bound acylCoAs, work in our lab has suggested that it also binds to fatty acids. Using recombinant ACBP, a series of fluorescence based assays were used to study ACBP's ability to bind long chain fatty acids. ACBP showed a strong binding affinity to unsaturated fatty acids, for example arachadonic acid (C20:4) bound with a Kd of 68.6±25.1 nM. Displacement assays also demonstrated that C20:4 fatty acid has high affinity binding to ACBP with a Kd value of 38.6±10.7 nM. The saturated fatty acids that we examined had Kd values that were very weak and questionable, or they displayed no response. This data is important for several reasons. Since fatty acids are necessary nutrients which at high levels can destroy cells, mammals have evolved proteins that bind or sequester them. Even though there are several proteins capable of binding fatty acids (i.e. fatty acid binding protein [FABP]L ACBP could compensate if such proteins were not working properly or were mutated. ACBP is thought to transport acyl-CoAs to the nucleus for interaction with nuclear receptors; by binding to fatty acids it could also be transporting fatty acids to the nucleus for interaction with nuclear receptors. Many nuclear receptors that bind fatty acids and/or fatty acyl-CoAs regulate genes involved in metabolism, so by transporting fatty acids ACBP could also be playing a role in these processes.</p><p>This presentation occurred at the Wright State University Campus-Wide Celebration of Research, Scholarship and Creative Activities on April 8, 2011</p>