Apolipoproteins (apo) E and AI are exchangeable apolipoproteins that are critical for lipid transport processes mediated by plasma lipoproteins. They are structurally similar and consist of an N-terminal domain folded into an α-helical bundle and a C-terminal (CT) domain that is structurally less defined. Recently, a novel chimera was created by combining the CT domain of apoAI with insect apolipophorin III (apoLp-III): apoLp-III/CT-apoAI. This chimera adopted the lipid binding and self-association properties of apoA-I. To examine the domain organization of apoE, a chimera was engineered consisting of apoLp-III and the CT domain of apoE. SDS-PAGE and immunoblotting confirmed the successful expression and purification of this apoLp-III/CT-apoE chimera. Circular dichroism spectroscopy showed that the chimera had a similar α-helical content and protein stability compared to the parent proteins. Self-association studies revealed that the chimera formed oligomers similar to apoE. Further, apoLp-III/CT-apoE was able to solubilize phospholipid vesicles at an enhanced rate compared to apoLp-III. Similarly, the chimera showed improved protection of LDL aggregation upon incubation with phospholipase C compared to apoLp-III. These data show that the self-association and lipid binding properties of CT-apoE were transferred to apoLp-III. It also showed that CT apoA-I is more effective in phospholipid vesicle solubilization and promoting self-association. Based on these data and those from the previous chimera, the CT domains of apoAI and apoE mediate lipid binding and self-association activities in the absence of their respective NT domains, and these properties can be conferred to other proteins.
|Advisor:||Weers, Paul M M|
|Commitee:||McAbee, Douglas D, Narayanaswami, Vasanthy|
|School:||California State University, Long Beach|
|Department:||Chemistry and Biochemistry|
|School Location:||United States -- California|
|Source:||MAI 81/4(E), Masters Abstracts International|
|Subjects:||Biochemistry, Molecular biology|
|Keywords:||apoA, apoE, apolipoprotein, apoLp-III, chimera|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be