4 research outputs found
Creativity and Autism Spectrum Conditions: a Hypothesis on Lewis Carroll
The hypothesis formulated by Simon Baron-Cohen and his collaborators on the onset of autistic syndromes and their link with an excess of the so-called S brain is reflected in the work of Lewis Carroll, a formal logic and mathematics professor deeply inclined to visual and spatial descriptions, interested in affordances and systemic circuits, and devoid of empathic tendencies in creating his characters. In the future, this finding may serve as a test for predicting autism spectrum disorders and support the elaboration of narrative artefact for therapeutic purposes in relation to people with autism
Creativity and Autism Spectrum Conditions: a Hypothesis on Lewis Carroll
The hypothesis formulated by Simon Baron-Cohen and his collaborators on the onset of autistic syndromes and their link with an excess of the so-called S brain is reflected in the work of Lewis Carroll, a formal logic and mathematics professor deeply inclined to visual and spatial descriptions, interested in affordances and systemic circuits, and devoid of empathic tendencies in creating his characters. In the future, this finding may serve as a test for predicting autism spectrum disorders and support the elaboration of narrative artefact for therapeutic purposes in relation to people with autism
Characterization of cellulases produced by trichoderma longibrachiatum DIBAF-10 using differential scanning calorimetry
Conversion of cellulose to soluble sugars by enzymatic hydrolysis is a key step for production of biofuels from lignocellulosic biomass. Efficient hydrolysis of cellulose requires the action of three different classes of enzymes: endoglucanase (1,4-β-d-glucan glucohydrolase [EC 3.2.1.4]), exoglucanase (1,4-β-d-glucan cellobiohydrolase [EC 3.2.1.91]), and β-glucosidase (β-d-glucoside glucohydrolase, [EC3.2.1.21]) [1]. Trichoderma longibrachiatum DIBAF-10 produced a cellulase cocktail tailored for the saccharification of milk thistle (Silybum marianum) with the potential to compete with commercial enzymes.
In this study, crude cellulase preparations from T. longibrachiatum DIBAF-10 were thermally studied by differential scanning calorimetry (DSC), to assess the conformational transitions between the folded and unfolded structure of the proteins and the relationship between them and the energetics of their stability. Generally, the aggregation can take place concurrently with the irreversible thermal denaturation and the conformational unfolding or accompanies an exothermal effect that results in formation of precipitation [2]. The study of thermal properties is essential to better characterize and understand the interactions between cellulase and its substrates and their dependence on temperature. In fact, enzyme thermo-stability is essential during saccharification reaction because steam is always used to make the substrates more suitable for the enzymatic hydrolysis [3].
The present work shows that DSC profiles of crude enzyme samples from T. longibrachiatum DIBAF-10 provide important thermodynamic information, about the thermostability of the included proteins. The thermograms of crude enzyme coktails, and of the commercial ones, show similar exothermic peaks at 52,45±0,90°C and 49,5±0,95°C, respectively, and comparable H values. This is probably due to the same conformational change leading to aggregation of proteins.
DSC, moreover, is cost-effective tool to obtain “conformational fingerprinting” of the crude enzyme cellulase preparations
Differential scanning calorimetry (DSC) as a tool for studying thermal properties of a crude cellulase cocktail
Abstract: Differential scanning calorimetry (DSC) was used as an efficient and rapid tool in studying the conformational transitions between the folded and unfolded structures of cellulolytic enzymes. The thermal properties of two crude hydrolytic enzyme cocktails containing extracellular cellulases from Trichoderma longibrachiatum DIBAF-10 were analyzed and compared with three commercial cellulase preparations. Differences in the thermal behavior of fungal cellulases in the liquid phase, freeze-dried state, liquid formulations in sodium citrate buffer (pH 4.8), and contact with cellulose, carboxymethyl cellulose, and cellobiose were evaluated. DSC profiles of cellulases from the DIBAF-10 strain provided important thermodynamic information about the thermal stability of the included proteins. Crude enzyme cocktails underwent a reproducible and irreversible exothermic aggregation phenomenon at 52.45 ± 0.90 °C like commercial β-glucosidase. Freeze-dried and resuspended in a sodium citrate buffer, cellulases from T. longibrachiatum showed an endothermic peak dependent on buffer and enzyme concentration. In the enzyme-substrates systems, a shift of the same peak was recorded for all substrates tested. The thermal analysis of freeze-dried cellulase samples in the range of 20–150 °C gave information on the denaturation process. In conclusion, we demonstrated that DSC is a cost-effective tool for obtaining "conformational fingerprinting" of crude fungal cellulase preparations. Graphical abstract: [Figure not available: see fulltext.].6n