Lambda-carrageenase

Lambda-carrageenase
Identifiers
EC no.3.2.1.162
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
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Lambda-carrageenase (EC 3.2.1.162, endo-beta-1,4-carrageenose 2,6,2'-trisulfate-hydrolase) is an enzyme which breaks down a polysaccharide found in red seaweeds, lambda-carrageenan. This enzyme has only been found in marine bacteria.[1][2]

Species distribution

Two bacteria which produce lambda-carrageenase have been found. The marine bacterium Pseudoalteromonas carrageenovora (also known as Alteromonas carrageenovora) strain ATCC 43555, which was isolated from sea water in Nova Scotia, and the deep-sea bacterial isolate Pseudoalteromonas sp. CL19, which was isolated from a sediment sample from Suruga Bay, Japan.[1][2][3]

Properties of the enzyme

In both Alteromonas carrageenovora and Pseudoalteromonas sp. CL19, lambda-carrageenase is encoded by the cglA gene. The product of this gene is a protein consisting of 942 amino acids, this protein includes a 25 amino acid signal peptide.[1][2] Lambda-carrageenase is found as a monomer. Its optimum pH for activity is 7.0, and optimum temperature is 35 °C. The enzyme specifically hydrolyses lambda-carrageenan, and is not active against iota- and kappa-carrageenans, agarose or porphyran.[1]

Mechanism of action

Lambda-carrageenase cleaves the beta 1-4 glycosidic bonds in the linear backbone of lambda-carrageenan. This results in the formation of a tetrasaccharide: alpha-D-Galp2,6S(2)-(1->3)-beta-D-Galp2S-(1->4)-alpha-D-Galp2,6S(2)-(1->3)-D-Galp2S. This enzyme acts via a single displacement mechanism, causing an inversion of anomeric configuration of the substrate.[1][2]

References

  1. ^ a b c d e Ohta Y, Hatada Y (October 2006). "A novel enzyme, lambda-carrageenase, isolated from a deep-sea bacterium". J. Biochem. 140 (4): 475–81. doi:10.1093/jb/mvj180. PMID 16926183.
  2. ^ a b c d Guibet M, Colin S, Barbeyron T, et al. (May 2007). "Degradation of lambda-carrageenan by Pseudoalteromonas carrageenovora lambda-carrageenase: a new family of glycoside hydrolases unrelated to kappa- and iota-carrageenases". Biochem. J. 404 (1): 105–14. doi:10.1042/BJ20061359. PMC 1868830. PMID 17269933.
  3. ^ "LGC Standards: Certified reference materials".