Lysozymes have been confirmed to possess varieties of functions in a range of organisms. In the present study, we cloned and sequenced c-type lysozyme cDNAs, constructed the recombinant protein over-expression of c-type lysozyme and analyzed the expression of transcription level in various tissues. The c-type lysozyme cDNA contained an open reading frame of 759  bp encoding a polypeptide of 252 @entity1522 . The molecular weight of the deduced @entity535 of AjcLYZ is 26.7  kDa with an estimated pI of 4.66. Multiple sequence alignments revealed that AjcLYZ had two highly conserved active sites ( @entity367 147 and @entity2574 159) and eight typical @entity2569 residues. The tertiary structure and modeled AjcLYZ showed structural similarity to @entity18904 LYZ. The results of mRNA transcripts showed that the highest expression was found in the tube foot, followed by the muscle, body wall, and coelomic fluid. In contrast, the intestine, tentacle and respiratory tree exhibited very low expression levels. Under salinity stress, significant down-regulation of AjcLYZ was observed in response to salinity stress in the intestine and coelomic fluid. Significant up-regulation and down-regulation of AjcLYZ were observed in response to salinity stress in body wall and respiratory tree. The purified recombinant protein was analyzed by @entity214 -PAGE and a single band with a molecular mass of 45.09  kDa, which was in agreement with the theoretical size (26.7  kDa for AjcLYZ and 18.39  kDa Trx-His-S tags) of the recombinant protein. Radial diffusion assay was employed to determine the antimicrobial spectrum of recombinant AjcLYZ against three Gram-positive and Gram-negative bacteria, and three sea @entity9688 pathogenic Vibrio species. From the radius of the antimicrobial zone, it was found that recombinant AjcLYZ harbored remarkable in vitro inhibitive effect on tested Gram-positive bacteria, while lytic activity against Gram-negative bacteria was relatively weak. The results will provide new clues about the molecular mechanisms that regulate the salinity adaption system.

Expression of c-type lysozyme gene in sea XXXX (Apostichopus japonicus) is highly regulated and time dependent after salt stress.

@entity1522 :: ('CHEBI:33709', 'Chemical') :: ['amino acids'] @entity535 :: ('CHEBI:33704', 'Chemical') :: ['amino acid'] @entity2569 :: ('CHEBI:17561', 'Chemical') :: ['Cys'] @entity9688 :: ('3659', 'Species') :: ['cucumber'] @entity367 :: ('CHEBI:18237', 'Chemical') :: ['Glu'] @entity18904 :: ('74491', 'Species') :: ['Meretrix lusoria'] @entity2574 :: ('CHEBI:22660', 'Chemical') :: ['Asp'] @entity214 :: ('CHEBI:8984', 'Chemical') :: ['SDS']
@entity9688 :: (3659,Species) :: ['cucumber']
