114375-70-1Relevant articles and documents
An exo-β-(1→3)-d-galactanase from Streptomyces sp. provides insights into type II arabinogalactan structure
Ling, Naomi X.-Y.,Lee, Joanne,Ellis, Miriam,Liao, Ming-Long,Mau, Shaio-Lim,Guest, David,Janssen, Peter H.,Ková?, Pavol,Bacic, Antony,Pettolino, Filomena A.
experimental part, p. 70 - 81 (2012/05/04)
An exo-β-(1→3)-d-galactanase (SGalase1) that specifically cleaves the β-(1→3)-d-galactan backbone of arabinogalactan-proteins (AGPs) was isolated from culture filtrates of a soil Streptomyces sp. Internal peptide sequence information was used to clone and recombinantly express the gene in E. coli. The molecular mass of the isolated enzyme was ~45 kDa, similar to the 48.2 kDa mass predicted from the amino acid sequence. The pI, pH and temperature optima for the enzyme were ~7.45, 3.8 and 48 °C, respectively. The native and recombinant enzymes specifically hydrolysed β-(1→3)-d- galacto-oligo- or poly-saccharides from the upstream (non-reducing) end, typical of an exo-acting enzyme. A second homologous Streptomyces gene (SGalase2) was also cloned and expressed. SGalase2 was similar in size (47.9 kDa) and enzyme activity to SGalase1 but differed in its pH optimum (pH 5). Both SGalase1 and SGalase2 are predicted to belong to the CAZy glycosyl hydrolase family GH 43 based on activity, sequence homology and phylogenetic analysis. The K m and Vmax of the native exo-β-(1→3)-d- galactanase for de-arabinosylated gum arabic (dGA) were 19 mg/ml and 9.7 μmol d-Gal/min/mg protein, respectively. The activity of these enzymes is well suited for the study of type II galactan structures and provides an important tool for the investigation of the biological role of AGPs in plants. De-arabinosylated gum arabic (dGA) was used as a model to investigate the use of these enzymes in defining type II galactan structure. Exhaustive hydrolysis of dGA resulted in a limited number of oligosaccharide products with a trisaccharide of Gal2GlcA1 predominating.
Enzymatic syntheses and selective hydrolysis of O-β-d- galactopyranosides using a marine mollusc β-galactosidase
Giordano, Assunta,Tramice, Annabella,Andreotti, Giuseppina,Mollo, Ernesto,Trincone, Antonio
, p. 139 - 143 (2007/10/03)
The use of crude extract of the hepatopancreas of Aplysia fasciata, a large mollusc belonging to the order Anaspidea containing a β-galactosidase activity, was reported for the synthesis of different galactosides. Good yields with polar acceptors and the
1-O-Acetyl-β-D-galactopyranose: A novel substrate for the transglycosylation reaction catalyzed by the β-galactosidase from Penicillium sp.
Zinin, Alexander I.,Eneyskaya, Elena V.,Shabalin, Konstantin A.,Kulminskaya, Anna A.,Shishlyannikov, Sergei M.,Neustroev, Kirill N.
, p. 635 - 642 (2007/10/03)
1-O-Acetyl-β-D-galactopyranose (AcGal), a new substrate for β-galactosidase, was synthesized in a stereoselective manner by the trichloroacetimidate procedure. Kinetic parameters (KM and kcat) for the hydrolysis of 1-O-acetyl-β-D-galactopyranose catalyzed by the β-D-galactosidase from Penicillium sp. were compared with similar characteristics for a number of natural and synthetic substrates. The value for kcat in the hydrolysis of AcGal was three orders of magnitude greater than for other known substrates. The β-galactosidase hydrolyzes AcGal with retention of anomeric configuration. The transglycosylation activity of the β-D-galactosidase in the reaction of AcGal and methyl β-D-galactopyranoside (1) as substrates was investigated by 1H NMR spectroscopy and HPLC techniques. The transglycosylation product using AcGal as a substrate was β-D-galactopyranosyl-(1→6)-1-O-acetyl-β-D-galactopyranose (with a yield of ~70%). In the case of 1 as a substrate, the main transglycosylation product was methyl β-D-galactopyranosyl-(1→6)-β-D-galactopyranoside. Methyl β-D-galactopyranosyl-(1→3)-β-D-galactopyranoside was found to be minor product in the latter reaction.