Structure-function relationship of exchangeable apolipoproteins

Abstract

Exchangeable apolipoproteins play a vital role in lipid and lipoprotein homeostasis. To understand the lipid-binding mechanism of exchangeable apolipoproteins in this study the structure-function relationship of insect exchangeable apolipoprotein apolipophorin-III (apoLp-III) has been investigated by utilizing disulfide mutants of locust apoLp-III. Based on the ability of the disulfide mutants to interact with various lipid-surfaces the role of apoLp-III helices and loops during the lipid-binding process of apoLp-III has been elucidated. In the second part of the study the organization of two adjacent human apolipoprotein AI molecules in reconstituted discoidal lipoproteins was investigated by chemical cross-linking and mass spectrometry. The difficulties associated with the chemical cross-linking coupled with mass spectrometry approach are discussed in the second part.