Journal of Applied Microbiology, Vol.121, No.1, 115-125, 2016
T4 lysozyme fused with cellulose-binding module for antimicrobial cellulosic wound dressing materials
AimsBacterial infection is a major challenge in wound care. Antimicrobial wound dressings are of great value for treating wound infections. Endolysins are evolving as a new class of antimicrobials with multiple applications. This study describes the production and evaluation of T4 lysozyme (T4Lyz), product of gene e of the T4 bacteriophage, fused with Cellulose Binding Module (CBM) for facile immobilization to cellulosic wound dressing. Methods and ResultsGenes encoding T4Lyz-CBM and T4Lyz were cloned and expressed in Escherichia coli and the enzymes were purified by cation exchange chromatography. While the CBM tag did not alter the optimum pH and stability features of T4Lyz, the lytic activity of the fusion protein was lowered. The bactericidal activity of T4Lyz-CBM, determined by viable count plating assay after 1h incubation with Micrococcus lysodeikticus was 975% with 10gml(-1), and 9996% and 95% for E.coli and Pseudomonas mendocina, respectively, with 200gml(-1) enzyme. T4Lyz-CBM was immobilized to wound dressing gauze with a capacity of 55gmg(-1) matrix, whereas the unmodified T4Lyz did not exhibit any binding. The immobilized protein retained its bactericidal activity against Gram-positive and Gram-negative bacteria. Both free and immobilized T4Lyz-CBM, after heat denaturation, retained their bactericidal activities against Gram-negative bacteria only. The immobilized enzyme exhibited higher stability than the free enzyme when stored in dry form or in the presence of polyol stabilizers. ConclusionTagging T4Lyz with CBM provides a facile, irreversible binding to cellulosic wound dressing while retaining its activity. This approach may be suitable even for other antimicrobial enzymes and -peptides. Significance and Impact of the StudyThe spread of antibiotic resistance requires innovative strategies for discovery and development of effective antimicrobial alternatives. This report presents a novel strategy for producing antimicrobial wound dressing materials.
Keywords:antimicrobial activity;cellulose binding module;fusion protein;immobilization;storage stability;T4 lysozyme;wound dressing