C-type Lysozyme Gene Research Articles

Lysozyme Inhibitors as Tools for Lysozyme Profiling: Identification and Antibacterial Function of Lysozymes in the Hemolymph of the Blue Mussel.

Lysozymes are universal components of the innate immune system of animals that kill bacteria by hydrolyzing their main cell wall polymer, peptidoglycan. Three main families of lysozyme have been identified, designated as chicken (c)-, goose (g)- and invertebrate (i)-type. In response, bacteria have evolved specific protein inhibitors against each of the three lysozyme families. In this study, we developed a serial array of three affinity matrices functionalized with a c-, g-, and i-type inhibitors for lysozyme typing, i.e., to detect and differentiate lysozymes in fluids or extracts from animals. The tool was validated on the blue mussel (Mytilus edulis), whose genome carries multiple putative i-, g-, and c-type lysozyme genes. Hemolymph plasma of the animals was found to contain both i- and g-type, but not c-type lysozyme. Furthermore, hemolymph survival of Aeromonas hydrophila and E. coli strains lacking or overproducing the i- type or g-type lysozyme inhibitor, respectively, was analyzed to study the role of the two lysozymes in innate immunity. The results demonstrated an active role for the g-type lysozyme in the innate immunity of the blue mussel, but failed to show a contribution by the i-type lysozyme. Lysozyme profiling using inhibitor-based affinity chromatography will be a useful novel tool for studying animal innate immunity.

A novel c-type lysozyme from Litopenaeus vannamei exhibits potent antimicrobial activity

Lysozyme is relevant to the innate immune system as a vital protein for crustaceans. In the present study, we cloned and characterized a novel c-type lysozyme gene (LvLYZ) from the Pacific white shrimp (Litopenaeus vannamei). The obtained full-length cDNA of LvLYZ was 990 bp and contained an open reading frame of 693 bp. Its deduced amino acid sequence consisted of 230 amino acids (aa) with a 17 aa signal peptide at the N-terminal and 130 aa functional domains. The multiple sequence alignment (MSA) indicated that the typical active sites in LvLYZ were similarly conserved as c-type lysozymes from other species. The transcription of LvLYZ appeared in all detected tissues and had relatively higher expression levels in hemocytes, hepatopancreas, gill and intestine. The mRNA expression profiles of LvLYZ were up-regulated in hemocyte and hepatopancreas post the stimulation of Vibrio parahaemolyticus or white spot syndrome virus (WSSV), respectively. The recombinant protein of LvLYZ (rLvLYZ) exhibited antibacterial activities against various microbes, including Escherichia coli, Vibrio splendidus, Micrococcaus luteus, Vibrio parahaemolyticus and Staphylococcus aureus. These results indicated that LvLYZ could cope with bacteria in L. vannamei and may play a significant role in immune response against invading pathogens.

Effect of an Oral Bivalent Vaccine on Immune Response and Immune Gene Profiling in Vaccinated Red Tilapia (Oreochromis spp.) during Infections with Streptococcus iniae and Aeromonas hydrophila.

Simple SummaryStreptococcosis and aeromonasis are major bacterial diseases in tilapia cultures, causing mass mortality with substantial economic losses to global aquaculture. The development of oral monovalent vaccines to prevent these diseases has been attempted; still, the mechanism of immunity of oral bivalent vaccines against streptococcosis and aeromonasis infections, as well as the protective ability of the host against these two diseases, remains understudied. To explore the immunological role of an oral bivalent vaccine, we compared the immune responses and immune gene profiling in red tilapia post-challenged with Streptococcus iniae and Aeromonas hydrophila. Our results showed that the degrees of expression of different innate and adaptive immune-associated genes in both mucosal and systemic immune organs were significantly higher in the bivalent vaccinated fish compared to the monovalent and control (unvaccinated) groups.Streptococcosis and aeromonasis inflicted by Streptococcus iniae and Aeromonas hydrophila, respectively, have affected tilapia industries worldwide. In this study, we investigated antibody responses and explored the mechanisms of protection rendered by an oral bivalent vaccine in red tilapia following challenges with S. iniae and A. hydrophila. The results of specific IgM antibody response revealed that the IgM titers against S. iniae and A. hydrophila in the bivalent incorporated (BI) vaccine group were significantly higher (p < 0.05) than those in the bivalent spray (BS) vaccine fish and unvaccinated control fish throughout the experiment. Real-time qPCR results also showed that the gene expression of CD4, MHC-I, MHC-II, IgT, C-type lysozyme, IL-1β, TNF-α, and TGF-β remained significantly higher (p < 0.05) than that of the controls between 24 and 72 h post-infection (hpi) in both mucosal (hindgut) and systemic (spleen and head–kidney) organs of BI vaccinated fish. Furthermore, the highest relative expression of the TGF-β, C-type lysozyme, and IgT genes in the BI vaccinated group was observed in the challenged fish’s spleen (8.8-fold), head kidney (4.4-fold), and hindgut (19.7-fold) tissues, respectively. The present study suggests that the bivalent incorporated (BI) vaccine could effectively improve the immune function and activate both humoral and cell-mediated immunities in vaccinated red tilapia following the bacterial challenges.

Chicken-type lysozyme is a major bacteriolytic enzyme in the blood of the banded houndshark Triakis scyllium

We examined lysozyme activities in the serum and the leukocyte extracts of the banded houndshark Triakis scyllium. The serum exhibited lytic activity, but not the leukocyte extracts. The lytic substance in the serum was of approximately 14 kDa and the N-terminal amino acid sequence was YVYSK. cDNA cloning identified a C-type lysozyme (TsLysC) gene and two G-type lysozyme (TsLysG) cDNA clones of different lengths. The TsLysC gene encodes 149 amino acids residues, and the sequence derived from the N-terminal amino acid sequencing was displayed at position 17–21. TsLysG, on the other hand, contains two ORFs that are homologous to the N- and C-terminal regions of G-type lysozyme of other fish species. TsLysC mRNA levels were high in the liver. TsLysG mRNA level was significantly lower than TsLysC mRNA in the liver.

Characterization and functional analysis of a c-type lysozyme gene from obscure puffer Takifugu obscurus

Lysozyme (Lyz) is an alkaline enzyme that hydrolyzes mucopolysaccharides in bacteria and is highly conserved vertebrates and invertebrates. In this study, a c-type lysozyme gene (named ToLyzC) from the obscure puffer Takifugu obscurus was cloned and characterized. The full-length cDNA of ToLyzC was 432 bp, encoding 143 amino acids, with a predicted molecular mass of 16.2 kDa and a theoretical pI of 8.86. The depicted protein sequence contained a LYZ1 domain from 16 to 142 amino acids, seven conserved cysteine residues. Phylogenetic analysis indicated that ToLyzC clustered with Lyzs from other teleost fishes. Quantitative real-time PCR analysis revealed that ToLyzC mRNA was mainly expressed in the liver. The transcript level of ToLyzC gene was significantly upregulated after Staphylococcus aureus and Vibrio harveyi challenge. The optimal pH and temperature of recombinant ToLyzC protein (rToLyzC) lytic activity was detected to be 7.5 and 35 °C, respectively. rToLyzC exhibited significant antibacterial and bacterial binding activities against S. aureus, Aeromonas hydrophila, V. harveyi, and Edwardsiella tarda at different time points. In addition, the morphological changes of V. harveyi cells treated with rToLyzC were observed under scanning electron microscope, which further confirmed the antibacterial and bacteriolytic activity of rToLyzC. Taken together, our current study indicated that ToLyzC is involved in the immune response to bacterial infection in obscure puffers.

Parallel Independent Losses of G-Type Lysozyme Genes in Hairless Aquatic Mammals.

Lysozyme enzymes provide classic examples of molecular adaptation and parallel evolution, however, nearly all insights to date come from chicken-type (c-type) lysozymes. Goose-type (g-type) lysozymes occur in diverse vertebrates, with multiple independent duplications reported. Most mammals possess two g-type lysozyme genes (Lyg1 and Lyg2), the result of an early duplication, although some lineages are known to have subsequently lost one copy. Here we examine g-type lysozyme evolution across >250 mammals and reveal widespread losses of either Lyg1 or Lyg2 in several divergent taxa across the mammal tree of life. At the same time, we report strong evidence of extensive losses of both gene copies in cetaceans and sirenians, with an additional putative case of parallel loss in the tarsier. To validate these findings, we inspected published short-read data and confirmed the presence of loss of function mutations. Despite these losses, comparisons of selection pressures between intact g- and c-type lysozyme genes showed stronger purifying selection in the former, indicative of conserved function. Although the reasons for the evolutionary loss of g-type lysozymes in fully aquatic mammals are not known, we suggest that this is likely to at least partially relate to their hairlessness. Indeed, although Lyg1 does not show tissue-specific expression, recent studies have linked Lyg2 expression to anagen hair follicle development and hair loss. Such a role for g-type lysozyme would explain why the Lyg2 gene became obsolete when these taxa lost their body hair.

Identification and characterization of the c-type lysozyme gene from a marine fish, Bostrychus sinensis

In this study, a c-type lysozyme gene (BsLyzC) was identified and characterized from a marine fish, Bostrychus sinensis. The BsLyzC encodes 154 amino acids and contains a signal peptide of 17 amino acids, two catalytic residues and eight cysteine residues. The genomic DNA of BsLyzC consists of four exons and three introns. The BsLyzC shares high sequence similarity with c-type lysozyme from other fish species. The qPCR assays indicated that the BsLyzC exhibited a constitutive expression pattern in eleven examined tissues of healthy B. sinensis individuals. The transcripts of BsLyzC could be significantly induced after infection of Vibrio parahemolyticus in blood, spleen and head kidney. The optimal temperature and pH for recombinant BsLyzC (rBsLyzC) were found to be 50 °C and 6.0, respectively. The rBsLyzC exhibited antibacterial activities against two Gram-positive bacteria and two Gram-negative bacteria. These results indicate that the BsLyzC is involved in the antibacterial immunity of B. sinensis.

Multiple Copies of the Fusion Gene cflyC-mzfDB3 Enhance the Expression of a Hybrid Antimicrobial Peptide in Pichia pastoris

The codon-optimized zebrafish β-defensin 3 mature peptide gene mzfDB3 and channel catfish c-type lysozyme gene cflyC were used to design the fusion gene cflyC-mzfDB3. In the fusion protein cflyC-mzfDB3, 4×Gly flexible amino acid linker with an enterokinase cleavage site DDDDK was designed to link the mzfDB3 to the C-terminus of cflyC, which potentially contributes to digestion of the recombinant cflyC-mzfDB3 by endogenous enterokinases. The fusion protein was expressed in Pichia pastoris X-33 using expression vectors harboring 1-, 2-, or 4-copies, respectively, of the expression cassette. The cflyC-mzfDB3 gene copy numbers of P. pastoris transformants were quantified using real-time quantitative PCR. Their expression yields showed that the expression level in the 4-copy cflyC-mzfDB3 transformant was 2.67-fold higher than that in the 1-copy cflyC-mzfDB3 transformant, demonstrating that the increase in the cflyC-mzfDB3 gene copy number resulted in increased protein expression. The culture medium supernatant containing recombinant cflyC-mzfDB3 exhibited antibacterial activity against Gram-positive Listeria monocytogenes and Gram-negative Pseudomonas aeruginosa, indicating that there may be a synergistic effect of mzfDB3 and cflyC on the peptide’s antibacterial activity. In addition, cell-free P. pastoris medium may be a potential candidate for further development as a natural hybrid antimicrobial solution.

Short Communication: Single nucleotide polymorphism in C-type lysozyme gene and its correlation with Aeromonas hydrophila resistance in African catfish Clarias gariepinus

Abstract. Authors. 2020. Short Communication: Single nucleotide polymorphism in C-type lysozyme gene and its correlation with Aeromonas hydrophila resistance in African catfish Clarias gariepinus. Biodiversitas 21: 311-317. The chicken-type lysozyme (LYSC) gene has been demonstrated to play important roles in the fish protection system against bacterial infection. In this present study, we aimed to identify the single nucleotide polymorphism (SNP) within the LYSC gene of African catfish Clarias gariepinus and its possible association with Aeromonas hydrophila resistance, a major pathogenic bacterium in African catfish. The gDNA of the African catfish LYSC coding sequence was 1559 bp long, comprising of four exons and three introns. Six SNPs were identified in African catfish LYSC, namely SNP1-6. After the A. hydrophila challenge, we regarded the surviving individuals after the infection as the resistant group and the dead fish as the susceptible group. High-resolution melting (HRM) analysis on SNP2 revealed that the allele frequencies of TT, CC, and TC were of 27.78%, 5.55%, and 66.67% in the resistant group, while the frequencies of TT, CC, and TC were 16.67%, 27.78%, and 55.55% in the susceptible group, respectively. The expression of LYSC and other immune-genes in the resistant group was also higher in the liver, head kidney, and spleen. These results indicated that the LYSC gene might play an essential role in bacterial resistance, and the SNP2 within the LYSC gene may be associated with the resistance to A. hydrophila in African catfish.

Adaptive Evolution of C-Type Lysozyme in Vampire Bats.

In mammals, chicken-type (c-type) lysozymes are part of the innate immune system, killing bacteria by degrading peptidoglycan in their cell walls. Many of the studies on the evolution of c-type lysozymes have focused on its new digestive function, including the duplicated stomach lysozymes in ruminants. Similarly, in bats, gene duplications and subsequent adaptive evolution of c-type lysozyme have been reported in a clade of insectivorous species, which might have been driven by the need to digest chitin. However, no studies on the evolution of c-type lysozyme have been carried out in the second largest and dietary diverse bat family Phyllostomidae, which includes insectivorous, frugivorous, nectarivorous and sanguivorous species. Here, we sequenced and analyzed c-type lysozyme genes from four phyllostomid bats, the common vampire bat, the white-winged vampire bat, the lesser long-nosed bat and the big fruit-eating bat. Only a single lysozyme gene was identified in each of these species. Evidence for positive selection on mature lysozyme was found on lineages leading to vampire bats, but not other bats with single copy lysozyme genes. Moreover, several amino acid substitutions found in mature lysozymes from the sanguivorous clade are predicted to have functional impacts, adding further evidence for the adaptive evolution of lysozyme in vampire bats. Functional adaptation of vampire bat lysozymes could be associated with anti-microbial defense, possibly driven by the specialized sanguivory-related habits of vampire bats.

Comparative transcriptomics and histopathological analysis of crucian carp infection by atypical Aeromonas salmonicida

Aeromonas salmonicida is a ubiquitous fish pathogen known to cause furunculosis. With the emergence of new subtypes and the expansion of the host range, it has threatened the health of a variety of marine and freshwater fish, particularly the non-salmonids, manifesting differently from the classical furunculosis. Although there have been reports of infection by atypical strains on the crucian carp, the pathogenesis and tissue pathology remain unclear. In this study, transcriptomics and histopathology were used to analyze the immune response and lesions of crucian carp infected with A. salmonicida. Comparative analysis showed 6579 differentially expressed genes (DEGs) (3428 down-regulated and 3151 up-regulated) were identified on day 5 post-infection (5 dpi). Further annotation and analysis revealed that the DEGs were enriched in enzyme regulator activity, response to oxidative stress, iron ion homeostasis and other functions, and mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), toll-like receptor (TLR), and nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) etc., and immune-related signaling pathways. Meanwhile, the four C-type lysozyme genes found in all DEGs were significantly up-regulated after infection. In addition, there was severe bleeding on the body of the infected fish. Also, the intestine, liver, spleen, and kidney showed varying degrees of inflammatory damage, especially the goblet cell hyperplasia of intestinal mucosa epithelium and degeneration and necrosis of renal tubular epithelium cells. Additionally, with the increase in pathogen concentration, the cumulative mortality increased, the severity of lesions in the hindgut and head-kidney tissues increased. The relative expression levels of four immune-related genes (TNF-α, IL-1β, IL-11, C-lysozyme) were also significantly upregulated, compared with the control (P < 0.05). In conclusion, this study provides a scientific basis for further study on the immune response, pathological diagnosis, and prevention of crucian carp infection caused by atypical A. salmonicida.

Effects of dietary probiotic supplementation on the growth, gut health and disease resistance of juvenile Nile tilapia (Oreochromis niloticus)

This study investigated the effects of the Streptococcus agalactiae antagonizing probiotics Bacillus cereus NY5 and Bacillus subtilis as feed additives for Nile tilapia in terms of growth performance, intestinal health and resistance to S. agalactiae. A total of 720 apparently healthy juvenile Nile tilapia (0.20 ± 0.05 g) were randomly divided into 4 equal groups with 3 replicates for each group. Fish were fed a basal diet (control check group, CK group) supplemented with B. subtilis (1 × 108 CFU/g feed, BS group), B. cereus NY5 (1 × 108 CFU/g feed, BC group), and B. subtilis + B. cereus NY5 (0.5 × 108 CFU/g feed of each probiotic, BS + BC group) for 6 wk, and the probiotic supplementation groups were then fed the basal diet for 1 wk to investigate the gut microbial community. The results of this study showed that BS + BC and BC treatments significantly increased weight gain (WG), feed conversion ratio (FCR) and S. agalactiae resistance in Nile tilapia (P < 0.05). Gut microvilli length and density and c-type lysozyme (lyzc) gene expression were significantly increased by probiotic supplementation (P < 0.05). The results of high-throughput sequencing showed that the B. cereus NY5 and B. subtilis + B. cereus NY5-supplemented feed resulted in a significant improvement in tilapia autochthonous gut bacterial communities and had a stimulation effect on a variety of potential probiotics after 6 wk of feeding. After cessation of probiotic administration for 1 wk, the gut bacteria of the fish in the BS + BC and BC groups had minor changes and maintained a stable state. Consequently, it was inferred that, as a feed supplement, B. cereus NY5 and the mixture of B. subtilis and B. cereus NY5 at 1 × 108 CFU/g feed were able to promote growth and disease resistance, which may be associated with the supplement's effects on gut immune status, intestinal morphology, and intestinal microbial community composition.

Molecular characterization, expression and antimicrobial activities of a c-type lysozyme from the mud crab, Scylla paramamosain

Lysozyme is an important immune protein involved in the first line of defense for crustaceans. In the present study, a c-type lysozyme gene (SpLyzC) was cloned and characterized from the mud crab, Scylla paramamosain. The full-length cDNA was 849 bp with an open reading frame of 669 bp, and encoded a polypeptide of 223 amino acids with a calculated molecular mass of 23.7 kDa and an isoelectric point of 8.90. SpLyzC shared conserved active sites with c-type lysozymes from other species, detected in all tested tissues and had higher expression levels in hepatopancreas and gill tissues. The expression of SpLyzC was up-regulated in hepatopancreas and gill after infection with Vibrio parahaemolyticus and Staphylococcus aureus. The density of bacteria in the hemolymph and the mortality of crabs increased following infection with V. parahaemolyticus after SpLyzC expression was silenced by injecting double-strand RNA of SpLyzC. The recombinant protein of the S. paramamosain c-type lysozyme (rSpLyzC) exhibited antibacterial activities against Micrococcus lysodeikticus, S. aureus, Vibrio harveyi and V. parahaemolyticus. These results indicate that SpLyzC could help eliminate bacteria in S. paramamosain and may play an important role in resistance to bacterial infection.

Intestinal Epithelial Wnt Signaling Mediates Acetylcholine-Triggered Host Defense against Infection

Regulated antimicrobial peptide expression in the intestinal epithelium is key to defense against infection and to microbiota homeostasis. Understanding the mechanisms that regulate such expression is necessary for understanding immune homeostasis and inflammatory disease and for developing safe and effective therapies. We used Caenorhabditis elegans in a preclinical approach to discover mechanisms of antimicrobial gene expression control in the intestinal epithelium. We found an unexpected role for the cholinergic nervous system. Infection-induced acetylcholine release from neurons stimulated muscarinic signaling in the epithelium, driving downstream induction of Wnt expression in the same tissue. Wnt induction activated the epithelial canonical Wnt pathway, resulting in the expression of C-type lectin and lysozyme genes that enhanced host defense. Furthermore, the muscarinic and Wnt pathways are linked by conserved transcription factors. These results reveal a tight connection between the nervous system and the intestinal epithelium, with important implications for host defense, immune homeostasis, and cancer.

C-type lysozyme gene haplotypes in Rhode Island Red layer chickens are associated with hatchability and survival.

C-type lysozyme gene haplotypes in Rhode Island Red layer chickens are associated with hatchability and survival.

Gene duplications and the evolution of c-type lysozyme during adaptive radiation of East African cichlid fish

The adaptive radiation of African cichlids is a prime model system for studying vertebrate speciation. Cichlid species are distributed in lakes and rivers with various water conditions such as various pH values. The innate immune system in fish is particularly important because water contains a wide range of pathogenic microorganisms. To investigate the evolution of the host defense system in cichlids, we isolated the c-type lysozyme gene, which functions in the innate immune system of fish. Southern blot and sequence analyses showed that the lysozyme gene underwent several gene duplication events and evolved with amino acid replacements during the adaptive radiation of cichlids. The inferred 3D structure revealed that the amino acid substitutions were localized on the lysozyme surface. Moreover, more than half of the surface substitutions changed the charge of amino acid residues, suggesting changes in the optimum pH for enzymatic activity. In African cichlids, the lysozyme genes may have played and still play an important role in defense against pathogens.

Multiple specialised goose-type lysozymes potentially compensate for an exceptional lack of chicken-type lysozymes in Atlantic cod.

Previous analyses of the Atlantic cod genome showed unique combinations of lacking and expanded number of genes for the immune system. The present study examined lysozyme activity, lysozyme gene distribution and expression in cod. Enzymatic assays employing specific bacterial lysozyme inhibitors provided evidence for presence of g-type, but unexpectedly not for c-type lysozyme activity. Database homology searches failed to identify any c-type lysozyme gene in the cod genome or in expressed sequence tags from cod. In contrast, we identified four g-type lysozyme genes (LygF1a-d) constitutively expressed, although differentially, in all cod organs examined. The active site glutamate residue is replaced by alanine in LygF1a, thus making it enzymatic inactive, while LygF1d was found in two active site variants carrying alanine or glutamate, respectively. In vitro and in vivo infection by the intracellular bacterium Francisella noatunensis gave a significantly reduced LygF1a and b expression but increased expression of the LygF1c and d genes as did also the interferon gamma (IFNγ) cytokine. These results demonstrate a lack of c-type lysozyme that is unprecedented among vertebrates. Our results further indicate that serial gene duplications have produced multiple differentially regulated cod g-type lysozymes with specialised functions potentially compensating for the lack of c-type lysozymes.

Cloning and expression analysis of c-type lysozyme gene in golden pompano, Trachinotus ovatus.

It is well known that lysozymes are key proteins to teleosts in the innate immune system and possess high bactericidal properties. In the present study, a c-type lysozyme gene (To-lysC) was cloned from golden pompano, Trachinotus ovatus. The To-lysC cDNA is composed of 743bp with a 36bp of 5'-UTR, 432bp open reading frame (ORF) and 275bp 3'-UTR, encoding a polypeptide of 144 amino acids (GenBank accession no: KT935522). Phylogenetic analysis revealed that To-lysC showed highest similarity to Perca flavescens lysC. Quantitative real-time PCR (qRT-PCR) analysis showed that To-lysC had relatively high expression level in the head kidney, gill and brain. After Vibrio harveyi infection, transcripts of To-lysC increased and reached its peak at 12h p.i. These results indicated that To-lysC may play an important role in innate immune response to bacteria.

Molecular Cloning and Characterization of a New C-type Lysozyme Gene from Yak Mammary Tissue.

Milk lysozyme is the ubiquitous enzyme in milk of mammals. In this study, the cDNA sequence of a new chicken-type (c-type) milk lysozyme gene (YML), was cloned from yak mammary gland tissue. A 444 bp open reading frames, which encodes 148 amino acids (16.54 kDa) with a signal peptide of 18 amino acids, was sequenced. Further analysis indicated that the nucleic acid and amino acid sequences identities between yak and cow milk lysozyme were 89.04% and 80.41%, respectively. Recombinant yak milk lysozyme (rYML) was produced by Escherichia coli BL21 and Pichia pastoris X33. The highest lysozyme activity was detected for heterologous protein rYML5 (M = 1,864.24 U/mg, SD = 25.75) which was expressed in P. pastoris with expression vector pPICZαA and it clearly inhibited growth of Staphylococcus aureus. Result of the YML gene expression using quantitative polymerase chain reaction showed that the YML gene was up-regulated to maximum at 30 day postpartum, that is, comparatively high YML can be found in initial milk production. The phylogenetic tree indicated that the amino acid sequence was similar to cow kidney lysozyme, which implied that the YML may have diverged from a different ancestor gene such as cow mammary glands. In our study, we suggest that YML be a new c-type lysozyme expressed in yak mammary glands that plays a role as host immunity.

Molecular cloning, recombinant protein expression, tissue distribution and functional analysis of a new c-type lysozyme from Lezhi black goat rumen

Zhang, P., Wang, Y., Jiang, M., Zhu, L., Li, J., Luo, M., Ren, H. and Liu, L. 2014. Molecular cloning, recombinant protein expression, tissue distribution and functional analysis of a new c-type lysozyme from Lezhi black goat rumen. Can. J. Anim. Sci. 94: 27-34. Three major distinct types of lysozymes have been identified in the animal kingdom and most lysozymes cloned from ruminants belong to the chicken-type (c-type). In this study, a new c-type lysozyme gene, named LZRLyz, was cloned and sequenced from the Lezhi black goat rumen. The LZRLyz cDNA has a 444 bp open reading frame (ORF) encoding a 147 amino acid polypeptide. The encoded polypeptide is predicted to have an 18 amino acid signal peptide, and a 129 amino acid mature protein with an isoelectric point (pI) of 6.08. The LZRLyz amino acid sequence shares 70.27% identity with the Capra hircus blood lysozyme and is grouped with other ruminants c-type lysozymes using the phylogenetic tree estimated by Neighbor-Jointing method. The recombinant express...