title: Protein purification and gene isolation of chlamysin, a cold-active lysozyme-like enzyme with antibacterial activity.
abstract: An antibacterial approximately 11 kDa protein designated chlamysin was isolated from viscera of the marine bivalve Chlamys islandica. Chlamysin inhibited the growth of all Gram-positive and Gram-negative bacteria tested. The isolated protein was highly efficient in hydrolyzing Micrococcus luteus cells only at low pH (4.5-6.2) and at low temperature (4-35 degrees C). No significant loss of enzyme activity was observed after 30 days storage at room temperature or after heating to 70 degrees C for 15 min, suggesting relatively high protein structure stability. Sequence-analyzed fragments of the protein revealed data which guided the isolation of the cDNA gene, encoding a 137 amino acid chlamysin precursor in scallops. The deduced protein contains a high portion of cysteine, serine and histidine residues and has a predicted isoelectric point below 7. The chlamysin protein was found to have sequence homology to an isopeptidase and to a recently published bivalve lysozyme.
authors.affiliation: Center of Marine Biotechnology, Norwegian Institute of Fisheries and Aquaculture, N-9291, Tromso, Norway.
authors.forename: I W
authors.initials: IW
authors.lastname: Nilsen
authors.forename: K
authors.initials: K
authors.lastname: Overbø
authors.forename: E
authors.initials: E
authors.lastname: Sandsdalen
authors.forename: E
authors.initials: E
authors.lastname: Sandaker
authors.forename: K
authors.initials: K
authors.lastname: Sletten
authors.forename: B
authors.initials: B
authors.lastname: Myrnes
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000494:pharmacology; D001483:Base Sequence; D018076:DNA, Complementary; D004795:Enzyme Stability; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D008826:Microbial Sensitivity Tests; D016982:Micrococcus luteus / Q000187:drug effects; D008969:Molecular Sequence Data; D009113:Muramidase / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology; D009994:Osmolar Concentration; D017386:Sequence Homology, Amino Acid
chemical_list: D000900:Anti-Bacterial Agents; D018076:DNA, Complementary; C403411:chlamysin; D009113:Muramidase