Lytic antimicrobial activity of hen egg white lysozyme immobilized to polystyrene beads.
Lysozyme [EC 3.2.1.17] was covalently attached to polystyrene resin beads by the sole histidine residue (His-15) through peptide spacers of various lengths. The spacers were amino acid chains composed of 6-aminocaproic acid synthesized with the solid phase peptide synthesis method. Immobilized lysozyme with a spacer length of three 6-aminocaproic acid units (2736 U/g resin with a protein load of 2.21 mg/g resin) displayed the greatest degree of hydrolytic activity against lyophilized Micrococcus lysodeikticus cell wall preparations. Enzymatic activity of immobilized lysozyme was 14.2% of that of the free enzyme. Preparations with longer spacers yielded higher total activity yet the retained activity was constant at about 14% level. A control that consisted of randomly coupled lysozyme to polystyrene beads without an amino acid spacer gave an enzyme activity of 158 U/g with a protein load of 1.24 mg/g resin which equated to 1.4% retained activity. Properties of the immobilized lysozyme system were studied, including stability and activity against soluble compared with insoluble substrates. A kinetics study of the immobilized lysozyme using Eadie-Hofstee plot parameters suggested significant external diffusion effects indicative of deviation from classic Michaelis-Menten kinetic behavior.
Wu
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Dept. of Food Science and Technology, Oregon State Univ., 100 Wiegand Hall, Corvallis, OR 97331, USA.
Daeschel
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MA
D015119:Aminocaproic Acid / Q000737:chemistry; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology; D002473:Cell Wall / Q000737:chemistry* / Q000187:drug effects; D004529:Egg White / Q000737:chemistry; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000494:pharmacology; D006639:Histidine / Q000737:chemistry; D007700:Kinetics; D008837:Micrococcus / Q000737:chemistry; D008863:Microspheres; D009113:Muramidase / Q000737:chemistry* / Q000494:pharmacology; D011137:Polystyrenes / Q000737:chemistry*
D000890:Anti-Infective Agents; D004800:Enzymes, Immobilized; D011137:Polystyrenes; D006639:Histidine; D009113:Muramidase; D015119:Aminocaproic Acid