Browsing by Subject "Enzima"

Now showing 1 - 3 of 3
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    Byproducts from cassava industry: alternative substrates for cyclodextrin glycosyltransferase production by alkalophilic Bacillus trypoxylicola SM-02
    (Murcia: Servicio de Publicaciones de la Universidad de Murcia, 2020) Peixoto, Carine Mascena; Coelho, Sheila Lorena de Araújo; Cazetta, Marcia Luciana
    In the present work was studied the use of cassava peel flour (CPF), corn steep liquor (CSL), and cassava wastewater as substrates to produce cyclodextrin glycosyltransferase (CGTase) from a new alkalophilic isolate of Bacillus trypoxylicola SM-02 by submerged fermentation. The experiments were performed as a Central Composite Design 22 , totalizing 11 assays. An enzymatic activity of 352.53 U/mL was obtained using 1.5 g of CPF and 0.6 g of CSL. The optimum temperature and pH of CGTase was 55 °C and 8.0, respectively. The CGTase depicted a relative activity of more than 50% for 120 min at the optimum temperature. The only salt that positively influenced the CGTase activity was CaCl2. The results are indicative of a potential role of B. trypoxylicola SM-02 in the production of CGTase using residual substrates.
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    Conferencia 'Aplicaciones industriales de las enzimas'
    (2011-05-20) Urbina, Luis
    Conferencia 'Aplicaciones industriales de las enzimas', a cargo de Ramiro Martínez Gutiérrez, Novozymes Spain. Patrocina: Vicerrectorado de Investigación. Salón de Grados de la Facultad de Biología. Campus de Espinardo.
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    Structural Determinants of the Specific Activities of an L-Amino Acid Oxidase from Pseudoalteromonas luteoviolacea CPMOR-1 with Broad Substrate Specificity
    (MDPI, 2022-07-24) Mamounis, Kyle J.; Caldas Nogueira, Maria Luiza; Marchi Salvador, Daniela Priscila; Andreo-Vidal, Andrés; Sanchez-Amat, Antonio; Davidson, Victor L.; Genética y Microbiología
    The Pseudoalteromonas luteoviolacea strain CPMOR-1 expresses a flavin adenine dinucleotide (FAD)-dependent L-amino acid oxidase (LAAO) with broad substrate specificity. Steady-state kinetic analysis of its reactivity towards the 20 proteinogenic amino acids showed some activity to all except proline. The relative specific activity for amino acid substrates was not correlated only with Km or kcat values, since the two parameters often varied independently of each other. Variation in Km was attributed to the differential binding affinity. Variation in kcat was attributed to differential positioning of the bound substrate relative to FAD that decreased the reaction rate. A structural model of this LAAO was compared with structures of other FAD-dependent LAAOs that have different substrate specificities: an LAAO from snake venom that prefers aromatic amino acid substrates and a fungal LAAO that is specific for lysine. While the amino acid sequences of these LAAOs are not very similar, their overall structures are comparable. The differential activity towards specific amino acids was correlated with specific residues in the active sites of these LAAOs. Residues in the active site that interact with the amino and carboxyl groups attached to the α-carbon of the substrate amino acid are conserved in all of the LAAOs. Residues that interact with the side chains of the amino acid substrates show variation. This provides insight into the structural determinants of the LAAOs that dictate their different substrate preferences. These results are of interest for harnessing these enzymes for possible applications in biotechnology, such as deracemization.