invertebrate type lysozyme

Lysozyme is a ubiquitous hydrolase that plays an important role in protecting the host against pathogenic infection. In the present study, the genomic DNA sequence of an invertebrate goose type (G type) lysozyme (designated CfLysG) was cloned from Zhikong scallop Chlamys farreri by genome walking technique. The full-length DNA of CfLysG gene was of 9455bp, and the fragment from the transcription site to the polyadenylation site was of 8217bp. A total of 104 SNPs and 29 ins-del polymorphisms were identified in the genomic sequence of CfLysG, and most of them were located in the promoter and intron regions, except for three SNPs located in the exon regions...

The response of the defense components lysozyme (LYZ), metallothionein (MT), and superoxide dismutase (SOD) to combined exposure to heavy metals and bacteria was assessed at transcriptional level in the surf clam Mactra veneriformis. First, the full-length LYZ cDNA containing 808 nucleotides and encoding 194 deduced amino acids was identified from the clam. Multiple alignments revealed that MvLYZ had a high identity with invertebrate-type LYZs from other mollusks. Next, clams were exposed to Vibrio parahaemolyticus and a mixture of cadmium and mercury, alone or in combination, for 7 days...

Lysozymes in animals have three types, namely chicken-type, goose-type, and invertebrate-type (i-type) lysozymes and all these 3 types have been found in bivalve mollusks. The i-type lysozymes in mollusks are involved in digestion and innate immunity. In this study, four different lysozyme genes that belong to i-type were identified from Hyriopsis cumingii. The HcLyso1 to HcLyso4 genes encode proteins with 144, 144, 161, and 228 amino acids, respectively, and contain a destabilase domain. HcLyso4 also contains SH3b domain in addition to its destabilase domain...

BACKGROUND: Insects thriving on nutritionally poor habitats have integrated mutualistic intracellular symbiotic bacteria (endosymbionts) in a bacteria-bearing tissue (the bacteriome) that isolates the endosymbionts and protects them against a host systemic immune response. Whilst the metabolic and physiological features of long-term insect associations have been investigated in detail over the past decades, cellular and immune regulations that determine the host response to endosymbionts and pathogens have attracted interest more recently...

We have created a Drosophila model of lysozyme amyloidosis to investigate the in vivo behavior of disease-associated variants. To achieve this objective, wild-type (WT) protein and the amyloidogenic variants F57I and D67H were expressed in Drosophila melanogaster using the UAS-gal4 system and both the ubiquitous and retinal expression drivers Act5C-gal4 and gmr-gal4. The nontransgenic w(1118) Drosophila line was used as a control throughout. We utilized ELISA experiments to probe lysozyme protein levels, scanning electron microscopy for eye phenotype classification, and immunohistochemistry to detect the unfolded protein response (UPR) activation...

Pathogens represent a universal threat to other living organisms. Most organisms express antimicrobial proteins and peptides, such as lysozymes, as a protection against these challenges. The nematode Caenorhabditis elegans harbours 15 phylogenetically diverse lysozyme genes, belonging to two distinct types, the protist- or Entamoeba-type (lys genes) and the invertebrate-type (ilys genes) lysozymes. In the present study we characterized the role of several protist-type lysozyme genes in defence against a nematocidal strain of the Gram-positive bacterium Bacillus thuringiensis...

When encountering a pathogen, all organisms evoke a protective response by inducing defense mechanisms to help fight off the invader. The invertebrate model organism Caenorhabditis elegans has proven to be valuable for studies of the host response and the small nematode mounts a substantial transcriptional response to numerous pathogens. Here, we use global quantitative proteomics to profile the response to infection with E. coli strain LF82 isolated from patients suffering from Crohn's disease, an inflammatory bowel disease...

Lysozymes play a key role in the innate immune system of vertebrates and invertebrates by hydrolyzing peptidoglycan, a vital component of the bacterial cell wall. Gram-negative bacteria produce various types of lysozyme inhibitors that allow them to survive the bactericidal action of lysozyme when their outer membrane is permeabilized. So far, three lysozyme inhibitor families have been described: the Ivy (inhibitor of vertebrate lysozyme) family, the MliC/PliC (membrane-associated/periplasmic lysozyme inhibitor of C-type lysozyme) family, and the PliI (periplasmic lysozyme inhibitor of I-type lysozyme) family...

Lysozymes function in animal immunity. Three types of lysozyme have been identified in animal kingdom and most lysozymes identified from bivalve molluscs belong to the invertebrate (i) type. In this research, we cloned and sequenced a new i-type lysozyme, named MmeLys, from the Asiatic hard clam Meretrix meretrix. MmeLys cDNA was constituted of 552 bp, with a 441 bp open reading frame encoding a 146 amino acid polypeptide. The encoded polypeptide was predicted to have a 15 amino acid signal peptide, and a 131 amino acid mature protein with a theoretical mass of 14601...

The last two decades of study enriched greatly our knowledge of how the immune system originated and the sophisticated immune mechanisms of today's vertebrates and invertebrates developed. Even unicellular organisms possess mechanisms for pathogen destruction and self recognition. The ability to distinguish self from non-self is a prerequisite for recognition of sexual compatibility and ensuring survival. Molecules involved in these processes resemble those found in the phagocytic cells of higher organisms...

A chicken-type lysozyme was obtained and characterized from the abalone Haliotis discus hannai Ino (HdLysC). The full-length cDNA of HdLysC was 586 bp, and it contained an open reading frame of 441 bp, encoding a 147-amino acid protein with a calculated molecular mass of 15.64 kDa and an isoelectric point of 4.87. The amino acid sequence of HdLysC possessed all conserved features critical for the fundamental structure and function of c-type lysozymes, including the two catalytic residues, Glu54 and Asp70. The genomic length of HdLysC was 2865 bp, with four exons interrupted by three introns...

Lysozyme is an important immune effector and is widely distributed in many organisms. In the present study, two novel invertebrate-type lysozymes (Pclysi1 and Pclysi2) were cloned from red swamp crayfish, Procambarus clarkii. Alignment analysis showed that these two genes were different in catalytic residues. Results of RT-PCR showed that these two genes share similar tissue distribution patterns, and both were upregulated after bacteria challenge. The mature recombinant proteins were expressed in Escherichia coli system and purified...

Lysozymes are antibacterial effectors of the innate immune system in animals that hydrolyze peptidoglycan. Bacteria have evolved protective mechanisms that contribute to lysozyme tolerance such as the production of lysozyme inhibitors, but only inhibitors of chicken (c-) and invertebrate (i-) type lysozyme have been identified. We here report the discovery of a novel Escherichia coli inhibitor specific for goose (g-) type lysozymes, which we designate PliG (periplasmic lysozyme inhibitor of g-type lysozyme)...

BACKGROUND: Lysozymes are enzymes that lyse bacterial cell walls, an activity widely used for host defense but also modified in some instances for digestion. The biochemical and evolutionary changes between these different functional forms has been well-studied in the c-type lysozymes of vertebrates, but less so in the i-type lysozymes prevalent in most invertebrate animals. Some bivalve molluscs possess both defensive and digestive lysozymes. RESULTS: We report a third lysozyme from the oyster Crassostrea virginica, cv-lysozyme 3...

Lysozymes are key proteins to invertebrates in the innate immune responses against bacterial infections. In this study, the full-length cDNA of a novel c-type lysozyme was cloned from the haemocytes of swimming crab Portunus trituberculatus using rapid amplification of cDNA ends (RACE) approaches. The full-length cDNA of lysozyme was of 984 bp, containing a 5' untranslated region (UTR) of 90 bp, a 3' UTR of 222 bp with a poly (A) tail, and an open reading frame (ORF) of 672 bp encoding an 18 amino acids signal peptide and a mature polypeptide of 205 amino acids with the predicted molecular weight of 23...

Lysozymes (EC 3.2.1.17) are hydrolytic enzymes, characterized by their ability to cleave the beta-(1,4)-glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine in peptidoglycan, the major bacterial cell wall polymer. In the animal kingdom, three major distinct lysozyme types have been identified--the c-type (chicken or conventional type), the g-type (goose-type) and the i-type (invertebrate type) lysozyme. Examination of the phylogenetic distribution of these lysozymes reveals that c-type lysozymes are predominantly present in the phylum of the Chordata and in different classes of the Arthropoda...

Lysozymes are key proteins to invertebrates in the innate immune responses against bacterial infections and providing nutrition as digestion enzymes. In the present study, an invertebrate type lysozyme (denoted as VpLYZ) was identified from Venerupis philippinarum haemocytes by cDNA library and RACE approaches. The full-length cDNA of VpLYZ consisted of 805 nucleotides with a canonical polyadenylation signal sequence AATAAA and a polyA tail, and an open-reading frame of 558bp encoding a polypeptide of 185 amino acids with a calculated molecular mass of 20...

Invertebrate (I-) type lysozymes, like all other known lysozymes, are dedicated to the hydrolysis of peptidoglycan, the major bacterial cell wall polymer, thereby contributing to the innate immune system and/or digestive system of invertebrate organisms. Bacteria on the other hand have developed several protective strategies against lysozymes, including the production of periplasmic and/or membrane-bound lysozyme inhibitors. The latter have until now only been described for chicken (C-) type lysozymes. We here report the discovery, purification, identification and characterization of the first bacterial specific I-type lysozyme inhibitor from Aeromonas hydrophila, which we designate PliI (periplasmic lysozyme inhibitor of the I-type lysozyme)...

As the nanotechnology industries increase production, nanoscale products will enter the aquatic environment, posing a possible threat to aquatic organisms. Suspension-feeding invertebrates may represent a unique target group for nanoparticle (NP) ecotoxicity, since they have highly developed processes for the cellular internalisation of nano- and microscale particles (endocytosis and phagocytosis), which are integral to key physiological functions such as intracellular digestion and cellular immunity. In the marine bivalve Mytilus, short-term exposure to nanosized carbon black (NCB) was shown to significantly affect immune parameters of immune cells, the hemocytes, in vitro...

Tapes japonica lysozyme (TJL), which belongs to the invertebrate-type lysozyme family, has a unique dimer formation. The residues, which include catalytic residues (glutamate 18 and aspartate 30), at the dimer interface form electrostatic interactions. Our previous study suggested that increasing the NaCl concentration switched TJL from a dimer to monomer structure, which increased TJL activity. Therefore, conversion from the dimeric to the monomeric structure is crucial for the TJL activity. In the present study, to further understand the effect of NaCl on TJL dimer formation, we examined the protein concentration and pH dependence of TJL activity in the presence or absence of 500 mM NaCl...