Structural & Functional Characterization of an Isophthalate Binding Protein, IphC from Comamonas testosteroni KF1

Abstract

Phthalates, highly toxic compounds used as plasticizers, pose a significant health risk to humans as they easily leach out into the environment. Isophthalate, a persistent pollutant and one of the isomers of phthalates, has become a growing concern for public health. While chemical methods for the degradation of plasticizers produce harmful byproducts, certain bacteria can break down these compounds entirely in their metabolism. Comamonas testosteroni KF1 is one such bacterium that has evolved a pathway to degrade isophthalate, wherein the first step involves the uptake of isophthalate by an isophthalate transporter. The solute-binding protein, IphC, of this transporter is anchored to the membrane and captures the isophthalate to transport it to the cytoplasm, where it is metabolized. This study focuses on the cloning, expression, purification, and characterization of IphC to understand its functional and structural properties as an isophthalate binding protein. The results of the study shed light on the uncharacterized IphC-mediated uptake of isophthalate and open up the possibility of engineering the isophthalate uptake mechanisms to enhance its potential for bioremediation. Overall, this study provides a better understanding of the binding interactions between isophthalate and IphC, which can be useful in development of eco-friendly methods for removing pollutants from the environment.