Human-derived lysozyme is a general term for a group of naturally occurring alkaline proteins in the human body that are capable of lysing bacterial cell walls. Its action is characterized by its ability to cleave the β-(1,4)-glycosidic bond between N-acetylglucosamine and N-acetylmuramic acid in peptidoglycan. Human-derived lysozyme has a variety of properties such as antibacterial, anti-inflammatory, antiviral and immune enhancing, and is therefore widely used in the domestic and international pharmaceutical markets. This review summarizes the structural features, expression sites, biological functions of human-derived lysozymes and its market applications.
Humans ; Muramidase ; Anti-Bacterial Agents

Recently, there has been a growing demand for natural preservatives because of increased consumer interest in health. In this study, we produced Lactobacillus rhamnosus cell-free supernatant (LCFS) and evaluated and compared its antimicrobial activity with existing natural preservatives against pathogenic microorganisms and in chicken breast meat contaminated with Escherichia coli and Staphylococcus aureus. Lactobacillus rhamnosus cell-free supernatant possessed 30 units of lysozyme activity and contained 18,835 mg/L of lactic acid, 2,051 mg/L of citric acid and 5,060 mg/L of acetic acid. Additionally, LCFS inhibited the growth of fourteen pathogenic bacteria, S. aureus, Bacillus cereus, Listeria monocytogenes, Vibrio parahaemolyticus, Listeria innocua, S. epidermidis, L. ivanovii, E. coli, Pseudomonas aeruginosa, Shigella sonnei, Shi. flexneri, Proteus vulgaris, Pseudomonas fluorescens, and Klebsiella pneumoniae. The antibacterial activity of LCFS was stronger than that of egg white lysozyme (EWL), Durafresh (DF) and grapefruit seed extract (GSE). Additionally, LCFS maintained its antimicrobial activity after heat treatment at 50℃~95℃ and at pH values of 3~9. Moreover, LCFS inhibited the growth of E. coli and S. aureus in chicken breast meat. In conclusion, it is expected that LCFS, which contains both lysozyme and three organic acids, will be useful as a good natural preservative in the food industry.
Acetic Acid ; Bacillus cereus ; Bacteria ; Breast ; Chickens ; Citric Acid ; Citrus paradisi ; Egg White ; Escherichia coli ; Food Industry ; Hot Temperature ; Hydrogen-Ion Concentration ; Klebsiella pneumoniae ; Lactic Acid ; Lactobacillus rhamnosus ; Lactobacillus ; Listeria ; Listeria monocytogenes ; Meat ; Muramidase ; Proteus vulgaris ; Pseudomonas aeruginosa ; Pseudomonas fluorescens ; Shigella sonnei ; Staphylococcus aureus ; Vibrio parahaemolyticus

Objective: To elucidate the possible role of human lysozyme-like protein 4 (LYZL4) in fertilization and characterize its enzymatic properties. METHODS: The localization of LYZL4 in human spermatozoa was investigated by immunofluorescence staining, the sources of LYZL4 on the sperm surface examined by RT-PCR, and the role of LYZL4 in fertilization assessed by the zona-free hamster egg penetration test. The recombinant plasmid pPIC9K-LYZL4 was constructed and its expression induced with methanol after transformed into competent Pichia pastoris GS115. The recombinant LYZL4 protein (rLYZL4) was purified from the fermentation supernatant and subsequently identified by Western blot. The hyaluronan binding ability of rLYZL4 was determined by ELISA and the muramidase activity, hyaluronidase activity, and free radical scavenging ability examined by spectrophotometric methods. RESULTS: Immunodetection with a specific antiserum localized LYZL4 on the acrosomal membrane of mature spermatozoa, which was exclusively secreted from the testis and epididymis as shown by RT-PCR. Immunoneutralization of LYZL4 significantly decreased the number of human spermatozoa bound to zona-free hamster eggs in a dose-dependent manner in vitro. The recombinant protein was expressed successfully by the P. pastoris strain GS115. Purified rLYZL4 exhibited a potent hyaluronan binding ability and a strong free radical scavenging ability but no muramidase or hyaluronidase activity. CONCLUSIONS LYZL4 secreted from the testis and epididymis is localized on the acrosomal membrane of mature spermatozoa and plays a role in sperm-egg binding as well as in binding hyaluronan and scavenging free radicals, which suggests that it might be a multi-functional molecule contributive to sperm protection and sperm-egg binding.
Acrosome ; enzymology ; Animals ; Blotting, Western ; Cricetinae ; Enzyme-Linked Immunosorbent Assay ; Epididymis ; Female ; Fertilization ; physiology ; Free Radical Scavengers ; metabolism ; Humans ; Hyaluronic Acid ; metabolism ; Male ; Muramidase ; analysis ; physiology ; Pichia ; Plasmids ; metabolism ; Recombinant Proteins ; analysis ; metabolism ; Sperm-Ovum Interactions ; physiology ; Spermatozoa ; enzymology ; Testis

Phagocytosis is a fundamental process in which phagocytes capture and ingest foreign particles including pathogenic bacteria. Several oral pathogens have anti-phagocytic strategies, which allow them to escape from and survive in phagocytes. Impaired bacteria phagocytosis increases inflammation and contributes to inflammatory diseases. The purpose of this study is to investigate the influences of various agents on oral pathogenic phagocytosis. To determine phagocytosis, Streptococcus mutans, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were stained with 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester (CFSE), and was measured using flowcytometery and confocal microscopy. The influencing factors on phagocytosis were evaluated through the pretreatment of ROS inhibitor (N-acetyl-L-cysteine (NAC)), lysozyme, potassium chloride (KCI) and adenosine triphosphate (ATP) in THP-1 cells. Expression of pro-inflammatory cytokines was determined by enzyme-linked immunosorbent assay (ELISA). The phagocytosis of various bacteria increased in a MOI-dependent manner. Among the tested bacteria, phagocytosis of P. gingivalis showed the highest fluorescent intensity at same infection time. Among the tested inhibitors, the NAC treatment significantly inhibited phagocytosis in all tested bacteria. In addition, NAC treatment indicated a similar pattern under the confocal microscopy. Moreover, NAC treatment significantly increased the bacteria-induced secretion of IL-1β among the tested inhibitors. Taken together, we conclude that the phagocytosis occurs differently depending on each bacterium. Down-regulation by ROS production inhibited phagocytosis and lead increased of oral pathogens-associated inflammation.
Adenosine Triphosphate ; Aggregatibacter actinomycetemcomitans ; Bacteria ; Cytokines ; Down-Regulation ; Enzyme-Linked Immunosorbent Assay ; Fusobacterium nucleatum ; Inflammation ; Macrophages ; Microscopy, Confocal ; Monocytes ; Muramidase ; Phagocytes ; Phagocytosis ; Porphyromonas gingivalis ; Potassium Chloride ; Streptococcus mutans ; United Nations

Bovine mastitis is an important microbial disease in the dairy industry. We investigated the frequencies of bacterial pathogens in 62 farms and pathogen antibiotic resistance from mastitis samples (n = 748). We tested the antimicrobial activity of chicken and duck egg white and lysozyme purified from chicken egg white. Moreover, we compared the microbiomes of normal and mastitic raw milk obtained by 16S rRNA gene pyrosequencing and culture methods. The results showed that the frequencies of Gram-positive pathogens (Enterococcus faecalis 37% and Staphylococcus aureus 36%) were higher than that of a Gram-negative pathogen (Escherichia coli 15%). Resistance frequencies to ampicillin and norfloxacin were lowest in Staphylococcus aureus (21%), Enterococcus faecalis (23%), and Escherichia coli (33%), and the antimicrobial activity of chicken egg white was higher than those of lysozyme and duck egg white. Pyrosequencing results revealed clear differences between the microbiomes of mastitic and normal raw milk samples and revealed a slightly similar, but clearly different, composition of pathogens compared to that from the culture method. Thus, pyrosequencing may be useful for elucidating changes in microbiomes during mastitis progression and treatment. A chicken egg white and antibiotic combination may help with mastitis treatment; however, further studies are needed.
Agriculture ; Ampicillin ; Animals ; Cattle ; Chickens ; Drug Resistance, Microbial ; Ducks ; Egg White* ; Enterococcus faecalis ; Escherichia coli ; Female ; Genes, rRNA* ; Mastitis ; Mastitis, Bovine* ; Methods ; Microbiota* ; Milk ; Muramidase ; Norfloxacin ; Ovum* ; Staphylococcus aureus

PURPOSE: The serum carcinoembryonic antigen (CEA) level has been recognized as a prognostic factor in colorectal cancer, and associated with response of rectal cancer to radiotherapy. This study aimed to identify CEA-interacting proteins in colon cancer cells and observe post-irradiation changes in their expression. MATERIALS AND METHODS: CEA expression in colon cancer cells was examined by Western blot analysis. Using an anti-CEA antibody or IgG as a negative control, immunoprecipitation was performed in colon cancer cell lysates. CEA and IgG immunoprecipitates were used for liquid chromatography–tandem mass spectrometry (LC-MS/MS) analysis. Proteins identified in the CEA immunoprecipitates but not in the IgG immunoprecipitates were selected as CEA-interacting proteins. After radiation treatment, changes in expression of CEA-interacting proteins were monitored by Western blot analysis. RESULTS: CEA expression was higher in SNU-81 cells compared with LoVo cells. The membrane localization of CEA limited the immunoprecipitation results and thus the number of CEA-interacting proteins identified. Only the Ras-related protein Rab-6B and lysozyme C were identified as CEA-interacting proteins in LoVo and SNU-81 cells, respectively. Lysozyme C was detected only in SNU-81, and CEA expression was differently regulated in two cell lines; it was down-regulated in LoVo but up-regulated in SNU-81 in radiation dosage-dependent manner. CONCLUSION: CEA-mediated radiation response appears to vary, depending on the characteristics of individual cancer cells. The lysozyme C and Rab subfamily proteins may play a role in the link between CEA and tumor response to radiation, although further studies are needed to clarify functional roles of the identified proteins.
Blotting, Western ; Carcinoembryonic Antigen ; Cell Line ; Colon* ; Colonic Neoplasms* ; Colorectal Neoplasms ; Immunoglobulin G ; Immunoprecipitation ; Mass Spectrometry ; Membranes ; Muramidase ; Radiotherapy ; Rectal Neoplasms

PURPOSE: The serum carcinoembryonic antigen (CEA) level has been recognized as a prognostic factor in colorectal cancer, and associated with response of rectal cancer to radiotherapy. This study aimed to identify CEA-interacting proteins in colon cancer cells and observe post-irradiation changes in their expression. MATERIALS AND METHODS: CEA expression in colon cancer cells was examined by Western blot analysis. Using an anti-CEA antibody or IgG as a negative control, immunoprecipitation was performed in colon cancer cell lysates. CEA and IgG immunoprecipitates were used for liquid chromatography–tandem mass spectrometry (LC-MS/MS) analysis. Proteins identified in the CEA immunoprecipitates but not in the IgG immunoprecipitates were selected as CEA-interacting proteins. After radiation treatment, changes in expression of CEA-interacting proteins were monitored by Western blot analysis. RESULTS: CEA expression was higher in SNU-81 cells compared with LoVo cells. The membrane localization of CEA limited the immunoprecipitation results and thus the number of CEA-interacting proteins identified. Only the Ras-related protein Rab-6B and lysozyme C were identified as CEA-interacting proteins in LoVo and SNU-81 cells, respectively. Lysozyme C was detected only in SNU-81, and CEA expression was differently regulated in two cell lines; it was down-regulated in LoVo but up-regulated in SNU-81 in radiation dosage-dependent manner. CONCLUSION: CEA-mediated radiation response appears to vary, depending on the characteristics of individual cancer cells. The lysozyme C and Rab subfamily proteins may play a role in the link between CEA and tumor response to radiation, although further studies are needed to clarify functional roles of the identified proteins.
Blotting, Western ; Carcinoembryonic Antigen ; Cell Line ; Colon* ; Colonic Neoplasms* ; Colorectal Neoplasms ; Immunoglobulin G ; Immunoprecipitation ; Mass Spectrometry ; Membranes ; Muramidase ; Radiotherapy ; Rectal Neoplasms

PURPOSE: Pleural effusion, an accumulation of fluid in the pleural space, usually occurs in patients when the rate of fluid formation exceeds the rate of fluid removal. The differential diagnosis of tuberculous pleurisy and malignant pleural effusion is a difficult task in high tuberculous prevalence areas. The aim of the present study was to identify novel biomarkers for the diagnosis of pleural fluid using proteomics technology. MATERIALS AND METHODS: We used samples from five patients with transudative pleural effusions for internal standard, five patients with tuberculous pleurisy, and the same numbers of patients having malignant effusions were enrolled in the study. We analyzed the proteins in pleural fluid from patients using a technique that combined two-dimensional liquid-phase electrophoresis and matrix assisted laser desorption/ionization-time of flight-mass spectrometry. RESULTS: We identified a total of 10 proteins with statistical significance. Among 10 proteins, trasthyretin, haptoglobin, metastasis-associated protein 1, t-complex protein 1, and fibroblast growth factor-binding protein 1 were related with malignant pleural effusions and human ceruloplasmin, lysozyme precursor, gelsolin, clusterin C complement lysis inhibitor, and peroxirexdoxin 3 were expressed several times or more in tuberculous pleural effusions. CONCLUSION: Highly expressed proteins in malignant pleural effusion were associated with carcinogenesis and cell growth, and proteins associated with tuberculous pleural effusion played a role in the response to inflammation and fibrosis. These findings will aid in the development of novel diagnostic tools for tuberculous pleurisy and malignant pleural effusion of lung cancer.
Biomarkers* ; Carcinogenesis ; Ceruloplasmin ; Chaperonin Containing TCP-1 ; Clusterin ; Diagnosis ; Diagnosis, Differential ; Electrophoresis ; Fibroblasts ; Fibrosis ; Gelsolin ; Haptoglobins ; Humans ; Inflammation ; Lung Neoplasms ; Methods* ; Muramidase ; Pleural Effusion ; Pleural Effusion, Malignant ; Prevalence ; Proteomics ; Spectrum Analysis ; Tuberculosis ; Tuberculosis, Pleural

Objective: To prepare a polyclonal antibody against human lysozyme-like protein 4 (LYZL4) expressed in the prokaryotic system and identify the distribution of LYZL4 in the testis. METHODS: The full-length cDNA of LYZL4 was cloned into the pET32a plasmid and the expression of the recombinant LYZL4 (rLYZL4) was induced by IPTG. The rLYZL4 was purified by Ni-NTA and chitin affinity chromatography respectively and its bactericidal activity was observed by bilayer agar plate diffusion assay. The purified rLYZL4 was used as an immunogen to generate the polyclonal antibody, followed by examination of the antibody titer by ELISA and its specificity by Western blot. The distribution of LYZL4 in human tissue, sperm and seminal plasma was identified and its subcellular localization in the testis was determined by immunohistochemistry. RESULTS: rLYZL4 was expressed efficiently in the prokaryotic system and exhibited no bacteriolytic activity against M. lysodeikticus and E. coli. The anti-rLYZL4 polyclonal antibody could bind the recombinant protein with a high sensitivity and specificity. LYZL4 was identified in the testis, epididymis and sperm protein extracts and localized in the acrosomal region of round and elongating spermatids. CONCLUSIONS An anti-rLYZL4 polyclonal antibody was successfully prepared using the prokaryotic expression system. LYZL4 was detected in the acrosomal region of round and elongating spermatids, suggesting an association with the structure and function of the acrosome.
Acrosome ; immunology ; Animals ; Antibodies ; analysis ; Blotting, Western ; DNA, Complementary ; Enzyme-Linked Immunosorbent Assay ; Epididymis ; immunology ; Escherichia coli ; Humans ; Immunohistochemistry ; Male ; Muramidase ; genetics ; immunology ; Plasmids ; Recombinant Proteins ; genetics ; Semen ; immunology ; Spermatozoa ; immunology ; Testis ; immunology

Previous studies have established a bovine mammary gland epithelia cells in vitro model by the adenovirus-mediated telomerase (hTERT-bMGEs). The present study was conducted to confirm whether hTERT-bMGEs were effective target cells to improve the efficiency of transgenic expression and somatic cell nuclear transfer (SCNT). To accomplish this, a mammary-specific vector encoding human lysozyme and green fluorescent protein was used to verify the transgenic efficiency of hTERT-bMGEs, and untreated bovine mammary gland epithelial cells (bMGEs) were used as a control group. The results showed that the hTERT-bMGEs group had much higher transgenic efficiency and protein expression than the bMGEs group. Furthermore, the nontransgenic and transgenic hTERT-bMGEs were used as donor cells to evaluate the efficiency of SCNT. There were no significant differences in rates of cleavage or blastocysts or hatched blastocysts of cloned embryos from nontransgenic hTERT-bMGEs at passage 18 and 28 groups (82.8% vs. 81.9%, 28.6% vs. 24.8%, 58.6% vs. 55.3%, respectively) and the transgenic group (80.8%, 26.5% and 53.4%); however, they were significantly higher than the bMGEs group (71.2%, 12.8% and 14.8%), (p < 0.05). We confirmed that hTERT-bMGEs could serve as effective target cells for improving development of somatic cell cloned cattle embryos.
Animals ; Blastocyst ; Cattle ; Clone Cells* ; Embryonic Structures* ; Epithelial Cells ; Humans ; In Vitro Techniques* ; Mammary Glands, Human* ; Muramidase ; Telomerase ; Tissue Donors