Dissertation/Thesis Abstract

Chimeras Provide Insight into Apolipoprotein Domain Organization
by Horn, James Vantirak Ching, M.S., California State University, Long Beach, 2019, 116; 22583217
Abstract (Summary)

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.

Indexing (document details)
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
Source Type: DISSERTATION
Subjects: Biochemistry, Molecular biology
Keywords: apoA, apoE, apolipoprotein, apoLp-III, chimera
Publication Number: 22583217
ISBN: 9781687914736
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