Molecular insights of a xyloglucan endo-transglycosylase/hydrolase of radiata pine (PrXTH1) expressed in response to inclination: Kinetics and computational study.
Plant Physiol Biochem
; 136: 155-161, 2019 Mar.
Article
em En
| MEDLINE
| ID: mdl-30684844
Xyloglucan endotransglycosylase/hydrolases (XTH) may have endotransglycosylase (XET) and/or hydrolase (XEH) activities. Previous studies confirmed XET activity for PrXTH1 protein from radiata pine. XTHs could interact with many hemicellulose substrates, but the favorite substrate of PrXTH1 is still unknown. The prediction of union type and energy stability of the complexes formed between PrXTH1 and different substrates (XXXGXXXG, XXFGXXFG, XLFGXLFG and cellulose) were determined using bioinformatics tools. Molecular Docking, Molecular Dynamics, MM-GBSA and Electrostatic Potential Calculations were employed to predict the binding modes, free energies of interaction and the distribution of electrostatic charge. The results suggest that the enzyme formed more stable complexes with hemicellulose substrates than cellulose, and the best ligand was the xyloglucan XLFGXLFG (free energy of -58.83⯱â¯0.8â¯kcalâ¯mol-1). During molecular dynamics trajectories, hemicellulose fibers showed greater stability than cellulose. Aditionally, the kinetic properties of PrXTH1 enzyme were determined. The recombinant protein was active and showed an optimal pH 5.0 and optimal temperature of 37⯰C. A Km value of 20.9â¯mM was determined for xyloglucan oligomer. PrXTH1 is able to interact with different xyloglycans structures but no activity was observed for cellulose as substrate, remodeling cell wall structure in response to inclination.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pichia
/
Proteínas de Plantas
/
Glicosiltransferases
Idioma:
En
Revista:
Plant Physiol Biochem
Assunto da revista:
BIOQUIMICA
/
BOTANICA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Chile
País de publicação:
França