Fatty Acid chain length and its effect on binding to serum albumin

[Eshi]

Homework Statement

The background: We performed an experiment testing the fatty acid binding difference of caproic (hexanoic) acid and lauric (dodecanoic) acid to bovine serum albumin. The experiment was performed using a fluorescent marking called ANS(which fluoresces when bound to bovine serum albumin). The results were interpreted as the % intensity verse the [fatty acid] so that the graph could be used to see how the fatty acids increasingly decrease the fluorescence of ANS biomarker, thereby showing that the fatty acids are competitively taking the place of ANS within the binding site.

Homework Equations

none

The Attempt at a Solution

I have found papers http://pubs.acs.org/doi/pdf/10.1021/ja01548a024, that show that fatty acids bind better with longer carbon chains. however, my data shows that initially at low concentrations the caproic acid binds better than lauric acid, but then after a slight increase in concentration the lauric quickly overtakes the caproic acid in binding.

any chance someone could help me?

 

[Eshi]

adding:

is it possible that bsa has multiple types of binding sites (we calculated 5 total sites for ANS) that are specific to the fatty acid, giving us the two different curve profiles of caproic acid and lauric acid?