Carla Machado

Centro Nacional de Pesquisa em Energia e Materiais | CNPEM · Brazilian Bioethanol Science and Technology Laboratory

Several signaling molecules that govern development in higher animals have been identified in the parasite Schistosoma mansoni, including the transforming growth factor β, protein tyrosine kinases, nuclear hormone receptors, among others. The Notch pathway is a highly conserved signaling mechanism which is involved in a wide variety of developmenta...

Galactanases (endo-β-1,4-galactanases—EC 3.2.1.89) catalyze the hydrolysis of β-1,4 galactosidic bonds in arabinogalactan and galactan side chains found in type I rhamnogalacturan. The aim of this work was to understand the catalytic function, biophysical properties, and use of a recombinant GH53 endo-beta-1,4-galactanase for commercial cocktail su...

A novel GH1 β-glucosidase (EaBgl1A) from a bacterium isolated from Antarctica soil samples was recombinantly overexpressed in E. coli cells and characterized. The enzyme showed unusual pH dependence with maximum activity at neutral pH and retention of high catalytic activity in the pH range 6 to 9, indicating a catalytic machinery compatible with a...

Objectives The use of endo-arabinanase from Bacillus licheniformis (ABNase) for sugarcane saccharification has been evaluated by enzyme immobilization and commercial cocktail supplement with the immobilized heterologous protein. Results Biochemical characterization of the purified ABNase showed that the catalytic activity was strongly inhibited...

Xylan is an abundant plant cell wall polysaccharide and its reduction to xylose units for subsequent biotechnological applications requires a combination of distinct hemicellulases and auxiliary enzymes, mainly endo-xylanases and ß-xylosidases. In the present work, a bifunctional enzyme consisting of a GH11 endo-1,4-β-xylanase fused to a GH43 β-xyl...

As part of an ongoing directed evolution program, the catalytic performance of the Xylanase A from Bacillus subtilis (XynA), which presents temperature and pH optima of 50°C and 6.0, respectively, has been enhanced to create a highly thermostable and alkali-tolerant enzyme. A library of random XynA mutants generated by error-prone polymerase chain...

An essential step in the conversion of lignocellulosic biomass to ethanol and other biorefinery products is conversion of cell wall polysaccharides into fermentable sugars by enzymatic hydrolysis. The objective of the present study was to understand the mode of action of hemicellulolytic enzyme mixtures for pretreated sugarcane bagasse (PSB) decons...

Product inhibition of β-glucosidases (BGs) by glucose is considered to be a limiting step in enzymatic technologies for plant-biomass saccharification. Remarkably, some β-glucosidases belonging to the GH1 family exhibit unusual properties, being tolerant to, or even stimulated by, high glucose concentrations. However, the structural basis for the g...

Efficient cellulose saccharification is crucial for the cost-effective production of ethanol from lignocellulosic biomass. Most ß-glucosidases are inhibited by glucose, and high enzyme loads are needed to attain acceptable hydrolysis yields, increasing the process costs. Therefore, glucosestimulated ß-glucosidases with high catalytic efficiency for...

PA28γ is a proteasome activator involved in the regulation of the cellular proliferation, differentiation and growth. In the present study, we identified and characterized a cDNA from Schistosoma mansoni exhibiting significant homology to PA28γ of diverse taxa ranging from mammals (including humans) to simple invertebrates. Designated SmPA28γ, this...

The in vitro schistosomicidal activity of curcumin (doses ranging from 5 to 100μM) was carried out against Schistosoma mansoni adult worms. Curcumin (at 50 and 100μM) caused death of all worms. When tested at the doses of 5 and 20μM, it decreased the worm viability in comparison with negative (Roswell Memorial Park Institute (RPMI) 1640 medium alon...