RRC ID 30774
Author Wang Y, Vilaplana F, Brumer H, Aspeborg H.
Title Enzymatic characterization of a glycoside hydrolase family 5 subfamily 7 (GH5_7) mannanase from Arabidopsis thaliana.
Journal Planta
Abstract Each plant genome contains a repertoire of β-mannanase genes belonging to glycoside hydrolase family 5 subfamily 7 (GH5_7), putatively involved in the degradation and modification of various plant mannan polysaccharides, but very few have been characterized at the gene product level. The current study presents recombinant production and in vitro characterization of AtMan5-1 as a first step towards the exploration of the catalytic capacity of Arabidopsis thaliana β-mannanase. The target enzyme was expressed in both E. coli (AtMan5-1e) and P. pastoris (AtMan5-1p). The main difference between the two forms was a higher observed thermal stability for AtMan5-1p, presumably due to glycosylation of that particular variant. AtMan5-1 displayed optimal activity at pH 5 and 35 °C and hydrolyzed polymeric carob galactomannan, konjac glucomannan, and spruce galactoglucomannan as well as oligomeric mannopentaose and mannohexaose. However, the galactose-rich and highly branched guar gum was not as efficiently degraded. AtMan5-1 activity was enhanced by Co(2+) and inhibited by Mn(2+). The catalytic efficiency values for carob galactomannan were 426.8 and 368.1 min(-1) mg(-1) mL for AtMan5-1e and AtMan5-1p, respectively. Product analysis of AtMan5-1p suggested that at least five substrate-binding sites were required for manno-oligosaccharide hydrolysis, and that the enzyme also can act as a transglycosylase.
Volume 239(3)
Pages 653-65
Published 2014-3
DOI 10.1007/s00425-013-2005-y
PMID 24327260
PMC PMC3928506
MeSH Amino Acid Sequence Arabidopsis / enzymology* Arabidopsis Proteins / metabolism* Computational Biology Mannosidases / metabolism* Molecular Sequence Data Recombinant Proteins / isolation & purification Recombinant Proteins / metabolism
IF 3.249
Times Cited 6
Arabidopsis / Cultured plant cells, genes pda08606