Investigating Arabidopsis thaliana α/β-hydrolase for potential to degrade poly(aspartic) acid
Faculty Mentor
Dr.Marylou Chitiyo
Location
Savannah Ballroom
Type of Research
On-going
Session Format
Poster Presentation
College
Allen E. Paulson College of Engineering & Computing
Department
Biology Department and Biochemistry, Chemistry, and Physics Department
Abstract
Polyaspartic acid (PAA) is a biodegradable polymer and is increasingly being incorporated into agricultural systems as a biostimulant to enhance nutrient availability and crop performance. Its protein-like backbone and abundant negatively charged carboxyl groups make PAA well-suited for interaction with biological systems, biodegradation, and environmentally friendly applications. Although bacterial hydrolases have generally been implicated in the biodegradation process of PAA into aspartate, plants are known to release root extracellular enzymes, including α/β-hydrolases into the rhizosphere. However, it is not clear whether plant hydrolases contribute to PAA association or breakdown. Previously, we showed that some hydrolase enzymes, nitrogen assimilation, and the amino acid metabolism pathways in Arabidopsis thaliana were upregulated in response to PAA (250 ppm). The objective of the study is to begin characterizing putative A. thaliana hydrolases for their potential to break down PAA. These enzymes belong to the α/β-hydrolase superfamily, based on predicted domains and other structural features, and were shown to be highly upregulated in response to PAA. Bioinformatics analyses were conducted using AlphaFold Server and PyMOL to predict the structure. The results show that the protein possesses structural and electrostatic features that enable interaction with PAA. We have established that the core α/β-hydrolase domains align with the structure of bacterial homologues that are known to interact with and degrade PAA. Currently, we attempted to identify expression conditions in E.coli with the aim of obtaining soluble enzyme to assay for activity. We have successfully expressed and purified the protein, establishing feasibility for downstream enzymatic characterization. Current efforts focus on identifying if enzymatic cleavage of the substrate PAA is occurring. Preliminary findings suggest enzymatic potential within plants to recognize and cleave polyaspartic acid, expanding the functional scope of plant α/β hydrolases. If confirmed these results open new avenues for understanding polymer–enzyme interactions.
Program Description
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Start Date
4-21-2026 10:00 AM
End Date
4-21-2026 12:00 PM
Recommended Citation
Bridges, Samaya; Kimmel, Rea; Chitiyo, Marylou PhD; Weiland, Mitch PhD; Shank, Nathaniel PhD; and dela Cerna, Mark PhD, "Investigating Arabidopsis thaliana α/β-hydrolase for potential to degrade poly(aspartic) acid" (2026). GS4 Student Scholars Symposium. 8.
https://digitalcommons.georgiasouthern.edu/research_symposium/2026A/2026A/8
Investigating Arabidopsis thaliana α/β-hydrolase for potential to degrade poly(aspartic) acid
Savannah Ballroom
Polyaspartic acid (PAA) is a biodegradable polymer and is increasingly being incorporated into agricultural systems as a biostimulant to enhance nutrient availability and crop performance. Its protein-like backbone and abundant negatively charged carboxyl groups make PAA well-suited for interaction with biological systems, biodegradation, and environmentally friendly applications. Although bacterial hydrolases have generally been implicated in the biodegradation process of PAA into aspartate, plants are known to release root extracellular enzymes, including α/β-hydrolases into the rhizosphere. However, it is not clear whether plant hydrolases contribute to PAA association or breakdown. Previously, we showed that some hydrolase enzymes, nitrogen assimilation, and the amino acid metabolism pathways in Arabidopsis thaliana were upregulated in response to PAA (250 ppm). The objective of the study is to begin characterizing putative A. thaliana hydrolases for their potential to break down PAA. These enzymes belong to the α/β-hydrolase superfamily, based on predicted domains and other structural features, and were shown to be highly upregulated in response to PAA. Bioinformatics analyses were conducted using AlphaFold Server and PyMOL to predict the structure. The results show that the protein possesses structural and electrostatic features that enable interaction with PAA. We have established that the core α/β-hydrolase domains align with the structure of bacterial homologues that are known to interact with and degrade PAA. Currently, we attempted to identify expression conditions in E.coli with the aim of obtaining soluble enzyme to assay for activity. We have successfully expressed and purified the protein, establishing feasibility for downstream enzymatic characterization. Current efforts focus on identifying if enzymatic cleavage of the substrate PAA is occurring. Preliminary findings suggest enzymatic potential within plants to recognize and cleave polyaspartic acid, expanding the functional scope of plant α/β hydrolases. If confirmed these results open new avenues for understanding polymer–enzyme interactions.
