# Project 2 - Structural Basis of HDL Maturation

> **NIH NIH P01** · VANDERBILT UNIVERSITY MEDICAL CENTER · 2020 · $236,967

## Abstract

ABSTRACT: PROJECT 2
Although circulating high density lipoproteins (HDL) are considered protective from cardiovascular disease, we
have a remarkably limited understanding of their structure. Furthermore, we understand even less about how
the major HDL protein, apolipoprotein (apo)A-I, interacts with other proteins to dictate HDL function. We will
test the hypothesis that apoA-I makes highly specific contacts with itself to form a molecular scaffold that
stabilizes HDL and facilitates, through specific protein:protein interactions, the association of HDL partner
proteins to define particle function. In our previous work, we used cross-linking chemistry and mass
spectrometry to generate detailed models of apoA-I in reconstituted particles as well as “real” HDL from human
plasma. Despite substantial differences in size and shape, these structures all shared the theme of an
antiparallel belt-like arrangement. Building on these discoveries, our goal is to further evaluate these and other
models using complementary structural techniques as well as evaluate the basis of apoA-I's interactions with
three major HDL components: apolipoprotein A-II, paraoxonase 1 (PON1) and cholesteryl ester transfer protein
(CETP). The specific aims are: 1) To test the Trefoil and other models of apoA-I in spherical reconstituted and
native or “real” plasma HDL using new dual isotope cross-linking techniques and state-of-the-art all-atom and
course grained molecular dynamics (MD) techniques in synergy with Segrest and Core B. 2) To determine the
molecular interactions between apoA-I and apoA-II using cross-linking and a new human apoA-II bacterial
expression system to derive the first models of native HDL particles containing both proteins (also in synergy
with Segrest). 3) To determine the molecular interactions between apoA-I and two important HDL docking
proteins, PON1 and CETP, using chemical cross-linking and site-directed mutagenesis. Along the way, we will
also use our experimental techniques to directly test structural models of LCAT being generated by Segrest in
Project 1 and evaluate the structure of potentially enhanced functional HDL isolated from lecithin:cholesterol
acyl transferase deficient subjects studied by Heinecke in Project 3. Our approach uniquely intertwines new
experimental techniques with state-of-the-art MD approaches resulting in structural knowledge that will be
directly applied to HDL function. Furthermore, our focus is on the structure of authentic HDL particles that are
circulating in normal individuals as well as those with rare genetic disorders. The structure of apoA-I
undoubtedly modulates HDL metabolism, and possibly mediates cardioprotective effects of some HDL
subspecies. Thus, a molecular understanding of its structure and its interactions with other proteins,
particularly those being explored as drug targets such as LCAT and CETP, is critical for the design of new
therapies exploiting reverse cholesterol transport and the anti-inflam...

## Key facts

- **NIH application ID:** 9951101
- **Project number:** 5P01HL128203-05
- **Recipient organization:** VANDERBILT UNIVERSITY MEDICAL CENTER
- **Principal Investigator:** W Sean Davidson
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $236,967
- **Award type:** 5
- **Project period:** — → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9951101

## Citation

> US National Institutes of Health, RePORTER application 9951101, Project 2 - Structural Basis of HDL Maturation (5P01HL128203-05). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9951101. Licensed CC0.

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