title: Novel alginate lyases from marine bacterium Alteromonas sp. strain H-4.
abstract: A bacterium Alteromonas sp. strain H-4 isolated from Laminaria fronds produced extra- and intra-cellular alginate lyases and utilized alginate as its sole carbon source. An extracellular alginate lyase was purified from the culture supernatant of the strain and its substrate specificity was characterized. The estimated molecular mass of the enzyme was 32 kDa and the isoelectric point was 4.7. Both polyM and polyG block degrading activities were observed using the substrate-containing gel overlay technique after isoelectric focusing of the enzyme. By analyzing the reaction products from the polyM block, polyG block, MG random block and intact alginate, three major peaks containing unsaturated tri-uronide through octa-uronide were detected for each substrate. The results indicate that the enzyme of Alteromonas sp. H-4 can degrade both polyM and polyG blocks with a K(m) in mg/mL 20-times higher for the polyM block.
authors.affiliation: Department of Food Science and Technology, Faculty of Fisheries, Hokkaido University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sawabe
authors.forename: M
authors.initials: M
authors.lastname: Ohtsuka
authors.forename: Y
authors.initials: Y
authors.lastname: Ezura
mesh_terms: D000464:Alginates / Q000378:metabolism; D000595:Amino Acid Sequence; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D016946:Gram-Negative Aerobic Rods and Cocci / Q000201:enzymology*; D007525:Isoelectric Focusing; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011133:Polysaccharide-Lyases / Q000737:chemistry / Q000302:isolation & purification*; D012623:Seawater / Q000382:microbiology; D013379:Substrate Specificity; D014574:Uronic Acids / Q000032:analysis
chemical_list: D000464:Alginates; D014574:Uronic Acids; D011133:Polysaccharide-Lyases; C016158:poly(beta-D-mannuronate) lyase