The recombinant AglB produced by Pichia pastoris exhibited substrate inhibition behavior for the hydrolysis of p-nitrophenyl α-galactoside, whereas it hydrolyzed the natural substrates, including galactomanno-oligosaccharides and raffinose family oligosaccharides, according to the Michaelian kinetics. These contrasting kinetic behaviors can be attributed to the difference in the dissociation constant of second substrate from the enzyme and/or to the ability of the leaving group of the substrates. The enzyme displays the grater kcat/Km values for hydrolysis of the branched α-galactoside in galactomanno-oligosaccharides than that of raffinose and stachyose. A sequence comparison suggested that AglB had a shallow active-site pocket, and it can allow to hydrolyze the branched α-galactosides, but not linear raffinose family oligosaccharides.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1080/09168451.2015.1136884 | DOI Listing |
Mikrochim Acta
January 2025
Jiaxing Key Laboratory of Molecular Recognition and Sensing, College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing, 314001, People's Republic of China.
A novel Ru-FeO nanozyme with enhanced peroxidase-like (POD-like) activity was synthesized through a hydrothermal method. Ru-FeO nanozyme was effectively utilized for the detection of thiophanate-methyl (TM) using a colorimetric technique. The POD-like activity of Ru-FeO was found to be superior compared to FeO, Rh-FeO, and Pd-FeO.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
College of Resources and Environment, Southwest University, Chongqing, 400716, China; Key Laboratory of Biomedical Analytics (Southwest University), Chongqing Science and Technology Bureau, College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China. Electronic address:
Background: Because arsenate (As(V)) is a highly toxic pollutant, timely on-site monitoring of its concentration is crucial for mitigating potential environmental and health hazards. Traditional on-site detection methods for As(V) often face limitations of long response time and low sensitivity. Nanozymes are nanomaterials that exhibit enzyme-like catalytic activity.
View Article and Find Full Text PDFBioorg Chem
January 2025
School of Biotechnology and Key Laboratory of Industrial Biotechnology of Education, School of Biotechnology, Jiangnan University, Wuxi 214122 China. Electronic address:
Achieving enzyme catalysis at high substrate concentrations is a substantial challenge in industrial biocatalysis, and the role of glycosylation in post-translational modifications that modulate enzyme substrate inhibition remains poorly understood. This study provides insights into the role of N-glycosylation in substrate inhibition by comparing the catalytic properties of d-lactonohydrolase (d-Lac) derived from Fusarium moniliforme expressed in prokaryotic and eukaryotic hosts. Experimental evidence indicates that recombinant d-Lac expressed in Pichia pastoris (PpLac-WT) exhibits higher hydrolysis rates at a substrate concentration of 400 g/L, with reduced substrate inhibition and enhanced stability compared to the recombinant d-Lac expressed in Escherichia coli (EcLac-WT).
View Article and Find Full Text PDFDev Cogn Neurosci
December 2024
Division of Psychology and Language Sciences, UCL, London WC1H 0AP, UK. Electronic address:
Executive functions can be classified into processes of inhibition, working memory and shifting, which together support flexible and goal-directed behaviour and are crucial for both current and later-life outcomes. A large body of literature has identified distinct brain regions critical to performing each of these functions. These findings are however predicated on a piecemeal and single-task approach.
View Article and Find Full Text PDFNeurochem Res
January 2025
Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Brain accumulation of the branched-chain α-keto acids α-ketoisocaproic acid (KIC), α-keto-β-methylvaleric acid (KMV), and α-ketoisovaleric acid (KIV) occurs in maple syrup urine disease (MSUD), an inherited intoxicating metabolic disorder caused by defects of the branched-chain α-keto acid dehydrogenase complex. Patients commonly suffer life-threatening acute encephalopathy in the newborn period and develop chronic neurological sequelae of still undefined pathogenesis. Therefore, this work investigated the in vitro influence of pathological concentrations of KIC (5 mM), KMV (1 mM), and KIV (1 mM) on mitochondrial bioenergetics in the cerebral cortex of neonate (one-day-old) rats.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!