Alginate lyases

A lyophilized preparation of alginate lyase from a dialysed extract of sonicated cells of a Pseudomonas sp. has been separated into three fractions by gel filtration.  

As well as degrading alginate, the fractions degraded a poly-L-guluronide and a polyuronide composed of D-mannuronic and L-guluronic acid residues, but not a poly-D-mannuronide, so that they appear to be endo-poly(L-guluronicacid) lyases. The properties of these enzymes have been investigated.  

The use of alginate lyases in structural studies of alginates has been described.  

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Table I. Products formed by Pectate Lyases Secreted by E. chrvsanthemi. L. multiparus. and C. populeti. or by Alginate Lyases Secreted by the Alg A Marine Bacterium...

This enzyme [EC 4.2.2.3], also referred to as poly(j8-D-mannuronate) lyase and poly(mana) alginate lyase, catalyzes the eliminative cleavage of polysaccharides containing /3-D-mannuronate residues to give oligosaccharides with 4-deoxy-o -L-eryt/iro-hex-4-enopyranuro-nosyl groups at their ends. 

BOROHYDRIDE REDUCTION ALDOL CONDENSATION ALDOSE 1-EPIMERASE ALDOSE REDUCTASE ALGINATE LYASE ALKALINE PHOSPHATASE,... 

Hattori, M., Ogino, A., Nakai, H., and Takahashi, K. 1997. Functional improvement of (3-lactoglobulin by conjugating with alginate lyase-lysate. J. Agric. Food Chem. 45, 703—708. 

Sato, R., Sawabe, T., and Saeki, H. 2005. Characterization of fish myofibriller protein by conjugation with alginate oligosaccharide prepared using genetic recombinant alginate lyase. J. Food Sci., 70, C58,2005. 

Wainwright M. (1981) Assay and properties of alginate lyase and 1.3-(3-glucanase in intertidal sands. Plant Soil 59, 83-89. 

Polysaccharide Lyases. The results on the modification of 4-0-methylglucuronic acid indicate that C5 epimerisation and elimination of 04 are comparably facile processes in vitro. Natural selection therefore predicts that where enzymes have evolved in the same organism, working on the same substrate, to perform both epimerisation and elimination, they should be structurally and evolutionarily related. A case in point is the alginate lyases and epimerases, although the sequences of modern lyases and epimerases are not similar, possibly because of the different stereochemical requirements of the... 

Sphingomonas A1 produces three alginate lyases, ALI (63kDa), ALII (23kDa) and ALIII (40kDa), the last two being formed by autocatalytic... 

ALII, which cleaves between guluronate residues, is a member of PL 8 and is one of the three structures in this family which have been solved.They are small enzymes (M = 20-30 kDa), Pacman-like molecules with the two jaws , which close over the substrate, being constructed from p-strands. There are no clues as to its mechanism, the structure-based guesswork being (probably erroneously) based on the assumption that the reaction is similar to the syn eliminations catalysed by M-M specific alginate lyases. 

PL 9 - Both chondroitin and alginate lyase. PL 9 contains both M-M alginate lyases and chondroitin lyases, which both catalyse syn eliminations. The one structure available (that of a chondroitinase from Flavobacterium heparinum) is of a helix of p-strands typical of enzymes acting on pectate, although three short a-helices are also in the structure. Despite the existence of a complex with —2 and —1 sites occupied, assignment of catalytic groups is speculative. 

Cellulases are enzymes contributing to biodegradation of algal biomass. Cellulases production has been recorded in representatives of all the four investigated species of luminous bacteria from CC IBSO. Alginate lyase production... 

Alginate lyase catalyzes cleavage of the glycosidic bond through /3-elimination. The similarity between the lyase reaction and the C-5 mannuronan epimerase reaction has been noted. Interestingly, the proteins share little sequence homology. 

The ACE-inhibitory and antihypertensive activities of Wakame hydrolysates have been investigated in another study, with a different research design (Sato et ah, 2002a,b). To obtain an isolated protein residue, Wakame was treated with alginate lyase S at 45 °C for 18 h and an enriched protein precipitate (46.3% dry matter) was recovered by centrifugation. Then Wakame was hydrolyzed using 17 kinds of proteases at different pH and temperature conditions, and ultrafiltered hydrolysates were tested for the inhibitory activity of the ACE. Among the proteases used in this study. 

An enzyme preparation from the marine brown alga Pelvetia canaliculata contained both alginate 5-epimerase and alginate lyase activities.Ca ions activated both enzymes, but Mn " ions only inhibited lyase activity. Increasing concentrations of substrate D-mannuronanate removed the inhibition of lyase activity by Mn ions. 

Alginate lyase from Turbo cornutus acted on sodium alginate and resulted in a rapid decrease in viscosity and a gradual increase in reducing power of the substrate solution. The result of gel filtration of the reaction products indicated that uronic acid oligosaccharides were liberated as the final product. The fact that the enzyme attacked preferentially the D-mannuronate-rich moieties of the alginate molecule was demonstrated by an analysis with paper electrophoresis of the reaction products after acid treatment, which separated the uronic acid oligosaccharides from the uronic acid polysaccharides. 

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