Document Type

Honors Thesis

Semester of Graduation

Spring 2026

Abstract

Lipoxygenases (LOXs) are non-heme iron containing enzymes that catalyze the oxygenation of polyunsaturated fatty acids (PUFAs) such as linoleic acid (LA). These lipoxygenase enzymes are found in both plants and animals. In humans, LOXs have been linked to inflammatory diseases such as asthma, atheroscelerosis, and allergic rhinitis. Plant LOXs have been primarily linked to the growth, development, and stress response of the plant. This paper focuses on Oryza sativa lipoxygenase-1 (OsLOX1), an enzyme found in rice (Oryza sativa). OsLOX1 has been associated with enhanced drought tolerance in rice and may play a role in regulating growth under water-limited conditions. Understanding its function could inform future strategies to improve crop resilience in the face of climate change. In order to better understand the molecular mechanism of OsLOX1, a structural model of the protein in action is helpful. The enzyme was overexpressed and purified before preliminary kinetic assays as well as crystallization trials were completed. Following crystallization and diffraction, a three-dimensional structure of the enzyme was obtained. We solved additional structures of OsLOX1 with calcium and a substrate mimetic to better understand activation of the enzyme. These structures provide a baseline for future structural/functional insights of OsLOX1. Additional studies will include site-directed mutagenesis of a Val to Phe to alter the oxygenation preference of the enzyme. X-ray structural studies along with enzyme kinetics will help elucidate the changes in the active site from this point mutation and could inform on possible correlations with OsLOX1s regulation to drought stress.

Awardee Name

Lillie Ballanco

Academic Major

Biological Sciences

Project Mentor

Nathaniel Gilbert

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