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Effects of murine lysozyme on lipopolysaccharide-induced biological activities
1Laboratory for Immunopharmacology of Microbial Products, Tokyo University of Pharmacy and Life Science, Japan.
Abstract:
We have demonstrated that egg-white lysozyme (EW-LZM) bound to lipopolysaccharide (LPS), reduced the lethal toxicity and the biological activity of LPS. In this study, the interaction of LPS with murine lysozyme (M-LZM) and the modulation of biological activities were investigated. M-LZM was prepared from the culture supernatant of the murine macrophage cell line RAW264.7 by ion-exchange and gel filtration chromatographies and dialysis. Two types of M-LZM, murine M lysozyme (MM-LZM) and murine P lysozyme (MP-LZM), were purified from the supernatant. The enzymatic activities of both MM-LZM and MP-LZM were inhibited by LPS and their effects were affected by the temperature and the ionic strength. TNF-alpha production from RAW264.7 by LPS was inhibited by mixing with MM-LZM and MP-LZM. MP-LZM inhibited TNF-alpha production stronger than MM-LZM. Considering these facts, we suggested that M-LZM, like EW-LZM, make a complex with LPS to reduce the toxicity of LPS together with inhibiting the enzymatic activity.
Insights
Murine lysozyme (M-LZM) binds to lipopolysaccharide (LPS), reducing LPS toxicity and biological activity. Both M-LZM types inhibited LPS-induced TNF-alpha production, with MP-LZM showing stronger inhibition.
Area of Science:
- Biochemistry
- Immunology
- Microbiology
Background:
- Egg-white lysozyme (EW-LZM) is known to bind lipopolysaccharide (LPS) and reduce its toxicity.
- Lipopolysaccharide (LPS) is a major component of Gram-negative bacteria, responsible for potent inflammatory responses.
- Lysozymes are enzymes with antibacterial properties that also interact with LPS.
Purpose of the Study:
- To investigate the interaction between murine lysozyme (M-LZM) and lipopolysaccharide (LPS).
- To determine if M-LZM can modulate the biological activities of LPS, similar to EW-LZM.
- To characterize the inhibitory effects of M-LZM on LPS-induced cytokine production.
Main Methods:
- Murine lysozyme (M-LZM) was purified from RAW264.7 cell culture supernatant using ion-exchange and gel filtration chromatography.
- Two types of M-LZM, murine M lysozyme (MM-LZM) and murine P lysozyme (MP-LZM), were isolated.
- Enzymatic activity assays and TNF-alpha production assays in RAW264.7 cells were performed to assess M-LZM-LPS interactions and effects.
Main Results:
- LPS inhibited the enzymatic activities of both MM-LZM and MP-LZM, with effects influenced by temperature and ionic strength.
- Both MM-LZM and MP-LZM inhibited LPS-induced TNF-alpha production from RAW264.7 cells.
- MP-LZM demonstrated a stronger inhibitory effect on TNF-alpha production compared to MM-LZM.
Conclusions:
- Murine lysozyme (M-LZM) forms complexes with LPS, similar to EW-LZM.
- Complex formation reduces the toxicity and biological activity of LPS.
- M-LZM plays a role in modulating inflammatory responses triggered by LPS.