The effects of peroxidase on the enzymatic and candidacidal activities of lysozyme.
OBJECTIVE
To investigate the effects of peroxidase or the peroxidase system on the enzymatic and candidacidal activities of lysozyme.


METHODS
The effects of peroxidase on lysozyme were examined by incubating hen egg-white lysozyme (HEWL) with bovine lactoperoxidase (bLPO). The influence of the peroxidase system on lysozyme was examined by the subsequent addition of potassium thiocyanate and hydrogen peroxide. Lysozyme activity was determined by the turbidity measurement of a Micrococcus lysodeikticus substrate suspension. Candidacidal activity was determined by comparing the colony forming units of Candida albicans ATCC 10231, ATCC 18804, and ATCC 11006. The Wilcoxon signed rank test was used to analyze the effects of variables.


RESULTS
bLPO at physiological concentrations enhanced the enzymatic activity of HEWL and its effect was dependent on bLPO concentration. The enhancement of enzymatic activity of HEWL by bLPO was affected by pH and ionic strength. The addition of potassium thiocyanate and hydrogen peroxide did not lead to an additional enhancement of the enzymatic activity of HEWL, as compared with bLPO alone. HEWL displayed candidacidal activity in all 3 strains of C. ablicans. The addition of bLPO alone did not affect the candidacidal activity of HEWL, but the bLPO system enhanced candidacidal activity of HEWL in all 3 strains of C. ablicans.


CONCLUSIONS
bLPO enhanced the enzymatic activity of HEWL, but the bLPO system did not show additional enhancement of the enzymatic activity of HEWL. The addition of bLPO did not affect the candidacidal activity of HEWL, but the bLPO system did enhance the candidacidal activity of HEWL.
Lee
Jeong-Yun
JY
Dept. of Oral Medicine and Oral Diagnosis, School of Dentistry and Dental Research Institute, Seoul National University, Chongro-Ku, Seoul 110-749, Republic of Korea.
Kim
Yoon-Young
YY
Chang
Ji-Youn
JY
Park
Moon-Soo
MS
Kho
Hong-Seop
HS
D000818:Animals; D000935:Antifungal Agents / Q000378:metabolism / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects*; D002417:Cattle; D015169:Colony Count, Microbial; D004347:Drug Interactions; D004529:Egg White / Q000737:chemistry; D020536:Enzyme Activators / Q000378:metabolism / Q000494:pharmacology; D007784:Lactoperoxidase / Q000378:metabolism / Q000494:pharmacology*; D050296:Microbial Viability / Q000187:drug effects; D009113:Muramidase / Q000378:metabolism / Q000494:pharmacology*; D011485:Protein Binding; D012471:Salivary Proteins and Peptides / Q000378:metabolism / Q000494:pharmacology*
D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D020536:Enzyme Activators; D012471:Salivary Proteins and Peptides; D007784:Lactoperoxidase; C421864:hen egg lysozyme; D009113:Muramidase