Lauren Paolucci

Student(s): Lauren Paolucci

Project: Biocomputational Insights into Oleosin’s Stabilizing Role in Lipid Droplets | View Poster (PDF)

Major(s): Bioengineering

Advisor(s): Wonpil Im

Abstract

Plant seed lipid droplets (LDs) are small organelles that play crucial roles in cellular functions, including serving as energy reservoirs during germination. LDs consist of a hydrophobic core composed of neutral lipids and are surrounded by a phospholipid monolayer. Without a means of stabilization, LDs in nature tend to coalesce, compromising their functionality. Oleosin, a structural protein abundantly found in LDs, embeds within the monolayer, preventing coalescence and providing the stability essential for plant survival. The mechanism by which oleosin stabilizes LDs is not well understood, and direct study of oleosin in LDs is challenging due to the organelle’s small size and high degree of light scattering. Therefore, detergent micelles have been adopted as model systems to analyze oleosin-LD interactions.

We utilized Förster Resonance Energy Transfer (FRET) to measure ten intramolecular distances across the hydrophobic region of oleosin in micelle systems, providing insights into its tertiary structure. To explore oleosin’s conformational differences in micelle and LD-like environments, we performed all-atom molecular dynamics simulations using the FRET distance measurements as restraints. This approach enables the ten intramolecular residue pairs to converge toward the experimentally measured distances, creating oleosin models consistent with the experimental protein, and facilitating accurate computational analysis of its structure and behavior in different lipid environments. In this work, we present the oleosin structures and dynamics and its interactions with different lipid environments, providing valuable insight into the stabilizing mechanisms of oleosin.