title: Conjugation and modeled structure/function analysis of lysozyme on glycine esterified cotton cellulose-fibers.
abstract: The antimicrobial activity of lysozyme covalently bound to glycine-derivatized cotton cellulose was assessed in a 96-well format. Lysozyme was immobilized on glycine-bound cotton through a carbodiimide reaction. The attachment to cotton fibers was made through both a single glycine and a glycine dipeptide esterified to cotton cellulose. Higher levels of lysozyme incorporation were evident in the diglycine-linked cotton cellulose samples. The antibacterial activity of the lysozyme-conjugated cotton cellulose against Bacillus subtilis was assessed as a suspension of pulverized cotton fibers in microtiter wells. Inhibition of B. subtilis growth was observed to be optimal within a range of 0.14-0.3 mM (equivalent to 4-20 mg of lysozyme-bound cotton/mL) of lysozyme. Enhancement of activity over soluble lysozyme may result from the solid-phase protection afforded by the cellulose linkage of the glycoprotein against proteolytic lysis. Computational models of lysozyme based on its crystal structure attached through aspartate, glutamate, and COOH-terminal residues to cellopentaose-(3) Gly-O-6-glycyl-glycine ester were constructed. The models demonstrate no steric constraints to the active-site cleft from the glycine-conjugated cellulose chain when lysozyme is bound at the carboxylates of Asp-87, Glu-7, Asp-119, Asp-18, and COOH-terminal Leu-129. The more robust antibacterial activity of the enzyme when bonded to cotton fibers suggests good potential for biologically active enzymes on cotton-based fabrics.
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, Cotton Textile Chemistry Unit, New Orleans, Louisiana 70179-0687, USA.
authors.forename: J V
authors.initials: JV
authors.lastname: Edwards
authors.forename: K
authors.initials: K
authors.lastname: Sethumadhavan
authors.forename: A H
authors.initials: AH
authors.lastname: Ullah
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects; D002240:Carbohydrate Sequence; D002482:Cellulose / Q000737:chemistry; D004951:Esterification; D005998:Glycine / Q000737:chemistry*; D003368:Gossypium / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009113:Muramidase / Q000737:chemistry* / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D002482:Cellulose; D009113:Muramidase; D005998:Glycine