Development of processes using modified proteases for the reduction of felting and shrinkage of wool textiles
type: CreativeWork
description: Four commercial proteases were characterised in terms of their activities, protein concentrations, optimum application conditions (pH and temperature) and suitable buffer systems in order to obtain maximum performance on wool. Different wool pre-treatments using oxidising or reducing agents in aqueous and solvent media were investigated. Effects of different types of surfactants on the activity of the protease Esperase were studied. Both non-ionic surfactant (Fabriwet NW) and anionic surfactant (Fabriwet AW) were compatible with Esperase and a specific type of anionic surfactant was found to significantly promote protease Esperase activity. Scanning electron microphotographs were used to monitor the degradation level of enzyme-treated wool samples as well as measurements of weight loss, tensile strength and shrinkage. Esperase was then covalently coupled to reversibly soluble-insoluble polymer Eudragit SI00 and LI00. Different coupling reactions in terms of polymer concentration, different washing methods to remove unmodified protease, presence or absence of l-Ethyl-3-(dimethylaminopropyl)carbodiimide hydrochloride (EDC) crosslinking agent and protease addition methods were investigated. The presence of EDC in the coupling reaction was confirmed to increase covalent fixation of the Esperase to the Eudragit and dropwise addition of enzyme also allowed more efficient covalent coupling. Washing of modified Esperase with acetate and phosphate buffer followed by Tris-Triton buffer was shown to give efficient removal of unmodified enzyme. The modification of proteases in this way not only increased their size so that they work on the surface of the wool cuticle but also increased their stability which is an important benefit from an industrial point of view. Results show that modified Esperase had a higher thermal stability than native Esperase at both 55 °C and 65 °C. Wool fabric was treated with modified Esperase and native Esperase at similar activity levels. Both show…
abstract: Four commercial proteases were characterised in terms of their activities, protein concentrations, optimum application conditions (pH and temperature) and suitable buffer systems in order to obtain maximum performance on wool. Different wool pre-treatments using oxidising or reducing agents in aqueous and solvent media were investigated. Effects of different types of surfactants on the activity of the protease Esperase were studied. Both non-ionic surfactant (Fabriwet NW) and anionic surfactant (Fabriwet AW) were compatible with Esperase and a specific type of anionic surfactant was found to significantly promote protease Esperase activity. Scanning electron microphotographs were used to monitor the degradation level of enzyme-treated wool samples as well as measurements of weight loss, tensile strength and shrinkage. Esperase was then covalently coupled to reversibly soluble-insoluble polymer Eudragit SI00 and LI00. Different coupling reactions in terms of polymer concentration, different washing methods to remove unmodified protease, presence or absence of l-Ethyl-3-(dimethylaminopropyl)carbodiimide hydrochloride (EDC) crosslinking agent and protease addition methods were investigated. The presence of EDC in the coupling reaction was confirmed to increase covalent fixation of the Esperase to the Eudragit and dropwise addition of enzyme also allowed more efficient covalent coupling. Washing of modified Esperase with acetate and phosphate buffer followed by Tris-Triton buffer was shown to give efficient removal of unmodified enzyme. The modification of proteases in this way not only increased their size so that they work on the surface of the wool cuticle but also increased their stability which is an important benefit from an industrial point of view. Results show that modified Esperase had a higher thermal stability than native Esperase at both 55 °C and 65 °C. Wool fabric was treated with modified Esperase and native Esperase at similar activity levels. Both show…
author: Zhang, Qinghua
license: https://dora.dmu.ac.uk/bitstreams/8d5b8e56-23d0-4408-9dc0-61a8690577b8/download
date published: 2007-07
date modified: 2026-07-24T06:18:31Z
provider: De Montfort University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: De Montfort University