Submitted to: Cellulose
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2011
Publication Date: 6/25/2011
Citation: Edwards, J.V., Prevost, N.T., Condon, B.D., French, A.D. 2011. Covalent attachment of lysozyme to cotton/cellulose materials: protein verses solid support activation. Cellulose. 18(5):1239-1249. Interpretive Summary: The creation of new markets for value-added, protective cotton textiles is currently an agriculture issue. Work in Southern Regional Research Center’s Cotton Textile Chemistry Unit is addressing the application of bio-active molecules to cotton textiles as a model to explore the creation of new value-added cotton products with highly selective properties and environmentally acceptable finishes. The highly absorbent, non-toxic, and soft-hand properties of cotton make it an attractive option as a biocompatible textile surface for clothes and biomedical materials. Recent interest in the development of antimicrobials attached to cotton materials include modifications that function through fiber entrapment with slow release activity, and covalent modifications designed to inhibit bacterial growth directly on the fiber. In this paper we show how the antimicrobial enzyme lysozyme can be attached to three types of cotton fabrics and still retain its activity. The potential application of lysozyme attached to cotton could be realized in the form of hygienic wipes, and protective apparel and hospital curtains. This paper lays the ground work for further exploration of the broad spectrum antimicrobial activity of lysozyme attached to cotton.
Technical Abstract: Covalent attachment of enzymes to cellulosic materials like cotton is of interest where either release or loss of enzyme activity over time needs to be avoided. The covalent attachment of an enzyme to a cellulosic substrate requires either activation of a protein side chain or an organic functional group on the cellulosic substrate. Use of a water soluble carbodiimide to create an amide linkage as the covalent attachment between the enzyme and substrate represents an aqueous-based alternative which may be preferred for textiles processes. Here we describe an amide bond-mediated lysozyme immobilization applied to cotton where either the carboxylate side chains of the protein or pendant carboxylates in a citrate, cross-linked cotton support are activated as the O-acyl-isourea intermediate, and the reactive amino nucleophiles are derived from amino-silanized cotton and the protein’s amino side chains, respectively. A comparison is made of the two actvation approaches to covalently link lysozyme to two different cotton fabrics using the water soluble carbodiimide 1-cyclohexyl-3-(2-morpholinoethyl)-carbodiimide-metho-p-toluene sulfonate. A comparison of the resulting enzyme activities of lysozyme on two different cotton supports showed that linking lysozyme to citrate crosslinked cotton gave higher activity than on aminosilanized cotton. The lysozyme-celluose conjugate formed on the citrate crosslinked nonwoven cotton fabric gave the highest yield and antimicrobial activity.