Molecular characterisation of a goose-type lysozyme gene in Atlantic cod (Gadus morhua L.)

Three goose-type lysozymes in the gastropod Oncomelania hupensis: cDNA sequences and lytic activity of recombinant proteins

“…They are thus all secreted molecules (Irwin and Gong, 2003), with extracellular roles in these animals. However, fish g-type lysozymes do not seem to have the secretion signal features at their N-terminal sequences (Irwin and Gong, 2003;Larsen et al, 2009), despite that a secreted peptide was observed in g-type lysozyme of Atlantic salmon (Salmo salar) (Kyomuhendo et al, 2007). Remarkably, the four conserved cysteines in g-type lysozymes of birds and mammals are not all found in those from scallops (Zou et al, 2005;Zhao et al, 2007), nor from the snail O. hupensis.…”

Crystal structures of g-type lysozyme from Atlantic cod shed new light on substrate binding and the catalytic mechanism

“…Crystallization, data collection, structure determination and analysis Recombinant expression and purification of cod g-type lysozyme (gLYS) is described by Larsen et al [20]. Crystals of gLYS suitable for X-ray diffraction studies were obtained by the hanging drop vapor diffusion method from 48 to 53% ammonium sulphate, 5 mM CoCl 2 and 0.1 M BisTris pH 6.5-7.0 at room temperature.…”

“…Primers D90A_F (5 0 -CCCTGGTTGGGGGGCCAATTATAATGG CTTTGG-3 0 ) and D90A_R (5 0 -CCAAAGCCATTATA ATTGGCCCCCCAACCAGGG-3 0 ) were used with the ''native'' expression construct (pET151/D-gLYS, as described [20]) to create the mutant D90A, while primer D101A_F (5 0 -GCTTTGGACTGATGCAGGTTGCTAAG AGATACCACGAACC-3 0 ) and D101A_R (5 0 -GGTTCGT GGTATCTCTTAGCAACCTGCATCAGTCCAAAGC-3 0 ) were used with either the ''native'' pET151/D-gLYS or pET151/D-gLYS D90A construct, to generate the single mutant D101A and the double mutant D90A/D101A, respectively. The expression vectors containing the mutants were transformed into XL-1 Blue (Stratagene) or Top10 (Invitrogen) super-competent cells.…”

“…The g-type lysozyme was initially identified as an antibacterial enzyme located in egg whites of Embden goose [12,13], but is now known to exist in both mammals and fish [3]. The first fish g-type lysozyme was reported in Japanese flounder in 2001 [14] and has since then also been reported from several other fish species [3,[15][16][17][18][19] including Atlantic cod [20]. Recombinant fish g-type lysozymes have been produced and their lytic activity against bacterial fish pathogens has been proven [14,18,19].…”

“…Recombinant fish g-type lysozymes have been produced and their lytic activity against bacterial fish pathogens has been proven [14,18,19]. The g-type lysozyme from Atlantic cod is shown to possess muramidase activity using Micrococcus luteus cells as substrate at an unusually low pH [20], but detailed structural knowledge explaining this pH activity profile is lacking. So far, the only crystal structures reported of g-type lysozymes are from the avian species Embden goose and Australian black swan which adopt a well-characterized a ?…”