Ultrapure LPS induces inflammatory and antibacterial responses attenuated in vitro by exogenous sera in Atlantic cod and Atlantic salmon.

Phagocyte recognition of lipopolysaccharide (LPS) is an early key event for triggering the host innate immune response necessary for clearance of invading bacteria. The ability of fishes to recognise LPS has been questioned as contradictory results have been presented. We show here that monocyte/macrophage cultures from Atlantic cod (Gadus morhua) and Atlantic salmon (Salmo salar) respond with an increased expression of inflammatory and antibacterial genes to both crude and ultrapure Escherichia coli LPS.

Efficient screening of marine extracts for protease inhibitors by combining FRET based activity assays and surface plasmon resonance spectroscopy based binding assays.

The screening of extracts from marine organisms is a widely used strategy to discover new drug leads. A common problem in the screening process is the generation of false positive hits through unspecific effects from the complex chemical composition of the crude extracts. In this study, we explored a combination of a fluorescence resonance energy transfer (FRET) based activity assay and a surface plasmon resonance (SPR) based binding assay to avoid this problem.

Enzyme characterisation and gene expression profiling of Atlantic salmon chicken- and goose-type lysozymes.

Lysozymes represent important innate immune components against bacteria. In this study, Atlantic salmon (Salmo salar) goose (g-) and chicken (c-) types of lysozyme were subjected to protein characterisations and tissue expression analyses. Specific bacterial protein inhibitors of g- and c-type lysozymes were employed to discriminate between respective enzyme activities.

The enzyme and the cDNA sequence of a thermolabile and double-strand specific DNase from Northern shrimps (Pandalus borealis).

Background: We have previously isolated a thermolabile nuclease specific for double-stranded DNA from industrial processing water of Northern shrimps (Pandalus borealis) and developed an application of the enzyme in removal of contaminating DNA in PCR-related technologies.

Methodology/principal Findings: A 43 kDa nuclease with a high specific activity of hydrolysing linear as well as circular forms of DNA was purified from hepatopancreas of Northern shrimp (Pandalus borealis). The enzyme displayed a substrate preference that was shifted from exclusively double-stranded DNA in the presence of magnesium to also encompass significant activity against single-stranded DNA when calcium was added.

Thermodynamics and structure of a salmon cold active goose-type lysozyme.

Atlantic salmon goose-type lysozyme (SalG) was previously shown to display features of cold-adaptation as well as renaturation following heat treatment. In this study differential scanning calorimetry (DSC) was carried out to investigate unfolding and potential refolding, while X-ray crystallography was used to study structural factors contributing to the temperature-related characteristics. The recombinant SalG has a melting temperature (T(m)) of 36.

Structural evidence for lack of inhibition of fish goose-type lysozymes by a bacterial inhibitor of lysozyme.

It is known that bacteria contain inhibitors of lysozyme activity. The recently discovered Escherichia coli inhibitor of vertebrate lysozyme (Ivy) and its potential interactions with several goose-type (g-type) lysozymes from fish were studied using functional enzyme assays, comparative homology modelling, protein-protein docking, and molecular dynamics simulations. Enzyme assays carried out on salmon g-type lysozyme revealed a lack of inhibition by Ivy.

Glutathione S-transferase from the Icelandic scallop (Chlamys islandica): isolation and partial characterization.

Glutathione S-transferase from the digestive gland of the cold-adapted marine bivalve Icelandic scallop was purified to apparent homogeneity by single GSTrap chromatography. The enzyme appeared to be a homodimer with subunit M(r) 22,000 having an optimum catalytic activity at pH 6.5-7.

Multiple invertebrate lysozymes in blue mussel (Mytilus edulis).

Initial analyses of lysozyme activities in individual blue mussels Mytilus edulis indicated variations in features of activity from the crystalline style to the remaining body parts (the soft body). Two separate larger scale lysozyme isolations were performed employing extracts from 1000 styles and 50 soft bodies, respectively. The soft body origin contained one, or one major, lysozyme that was purified to homogeneity.