Catalytic Performance of a Recombinant Organophosphate-Hydrolyzing Phosphotriesterase from Brevundimonas diminuta in the Presence of Surfactants

Meng-Chun Chi,Tzu-Fan Wang,Ting-Yu Liao,Long-Liu Lin,Min-Guan Lin

doi:10.3390/catal11050597

Abstract

Phosphotriestease (PTE), also known as parathion hydrolase, has the ability to hydrolyze the triester linkage of organophosphate (OP) pesticides and chemical warfare nerve agents, making it highly suitable for environment remediation. Here, we studied the effects of various surfactants and commercial detergents on the esterase activity of a recombinant PTE (His6-tagged BdPTE) from Brevundimonas diminuta. Enzymatic assays indicated that His6-tagged BdPTE was severely inactivated by SDS even at lower concentrations and, conversely, the other three surfactants (Triton X-100, Tween 20, and Tween 80) had a stimulatory effect on the activity, especially at a pre-incubating temperature of 40 °C. The enzyme exhibited a good compatibility with several commercial detergents, such as Dr. Formula® and Sugar Bubble®. The evolution results of pyrene fluorescence spectroscopy showed that the enzyme molecules participated in the formation of SDS micelles but did not alter the property of SDS micelles above the critical micelle concentration (CMC). Structural analyses revealed a significant change in the enzyme’s secondary structure in the presence of SDS. Through the use of the intentionally fenthion-contaminated Chinese cabbage leaves as the model experiment, enzyme–Joy® washer solution could remove the pesticide from the contaminated sample more efficiently than detergent alone. Overall, our data promote a better understanding of the links between the esterase activity of His6-tagged BdPTE and surfactants, and they offer valuable information about its potential applications in liquid detergent formulations.

Highlights

Enzymes are macromolecular biocatalysts that accelerate chemical reactions by providing an alternative reaction pathway with lower activation energy
To understand the impacts of SDS, Triton X-100, Tween 20, and Tween 80 on the esterase activity of His6 -tagged Brevundimonas diminuta PTE (BdPTE), the enzyme was pre-incubated with these surfactants at the indicated temperatures for 1 h, and the residual activity was immediately determined as described below
In the case studies of the enzymatic hydrolysis of cellulose and lignocellulose, non-ionic surfactants can make substrates more accessible for the enzyme [49], increase enzyme adsorption sites on the substrate’s reducing ends [50], stabilize the enzyme molecules during hydrolysis [51], reduce the non-productive adsorption of enzymes onto substrates [52], and avoid enzyme deactivation caused by shear force and the air

Summary

Introduction

Enzymes are macromolecular biocatalysts that accelerate chemical reactions by providing an alternative reaction pathway with lower activation energy. Certain enzymes are of great interest and are being used as catalysts in various biological processes for the largescale production of industrially important products [1,2]. The prime ingredients of detergents include surfactants, bleaching agents, builders, foam regulators, corrosion inhibitors, optical brighteners, and other minor additives (e.g., enzymes, perfumes, and fabric tensors) [3,4,5,6]. Surfactants, an essential component in most cleaning products are surface-active compounds that have been extensively applied to a wide range of industrial domains, including detergents, cosmetics, fabric softeners, paints, and emulsions [7]. The molecular interactions between enzymes and surfactants can be beneficial to promoting the catalytic performance [8,9,10,11]

Methods

Results

Conclusion