title: Alginate lyases from alginate-degrading Vibrio splendidus 12B01 are endolytic.
abstract: Alginate lyases are enzymes that degrade alginate through β-elimination of the glycosidic bond into smaller oligomers. We investigated the alginate lyases from Vibrio splendidus 12B01, a marine bacterioplankton species that can grow on alginate as its sole carbon source. We identified, purified, and characterized four polysaccharide lyase family 7 alginates lyases, AlyA, AlyB, AlyD, and AlyE, from V. splendidus 12B01. The four lyases were found to have optimal activity between pH 7.5 and 8.5 and at 20 to 25°C, consistent with their use in a marine environment. AlyA, AlyB, AlyD, and AlyE were found to exhibit a turnover number (kcat) for alginate of 0.60 ± 0.02 s(-1), 3.7 ± 0.3 s(-1), 4.5 ± 0.5 s(-1), and 7.1 ± 0.2 s(-1), respectively. The Km values of AlyA, AlyB, AlyD, and AlyE toward alginate were 36 ± 7 μM, 22 ± 5 μM, 60 ± 2 μM, and 123 ± 6 μM, respectively. AlyA and AlyB were found principally to cleave the β-1,4 bonds between β-d-mannuronate and α-l-guluronate and subunits; AlyD and AlyE were found to principally cleave the α-1,4 bonds involving α-l-guluronate subunits. The four alginate lyases degrade alginate into longer chains of oligomers.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors.forename: Ahmet H
authors.initials: AH
authors.lastname: Badur
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA Department of Chemical Engineering, Konkuk University, Seoul, Republic of Korea.
authors.forename: Sujit Sadashiv
authors.initials: SS
authors.lastname: Jagtap
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors.forename: Geethika
authors.initials: G
authors.lastname: Yalamanchili
authors.affiliation: Department of Chemical Engineering, Konkuk University, Seoul, Republic of Korea.
authors.forename: Jung-Kul
authors.initials: JK
authors.lastname: Lee
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors.forename: Huimin
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA chris@scs.uiuc.edu.
authors.forename: Christopher V
authors.initials: CV
authors.lastname: Rao
mesh_terms: D000464:Alginates / Q000378:metabolism*; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008190:Lyases / Q000302:isolation & purification / Q000378:metabolism*; D008958:Models, Molecular; D011487:Protein Conformation; D013696:Temperature; D014733:Vibrio / Q000201:enzymology*
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D008190:Lyases