10 research outputs found
AnĂĄlisis de suelo y foliar en guanĂĄbano (Annonamuricata L.) en blanca espuma municipio de Alto Lucero, Veracruz
AcĂșmulo de N, K, Ca, Mg e S na matĂ©ria seca da parte aĂ©rea de mudas de cajueiro-anĂŁo-precoce submetidas a nĂveis crescentes de matĂ©ria orgĂąnica
Exportação de macronutrientes pela castanha e pseudofruto de dois clones de cajueiro anão-precoce
Flavianate, an amino acid precipitant, is a competitive inhibitor of trypsin at pH 3.0
Textile dyes bind to proteins leading to selective co-precipitation of a complex involving one protein molecule and more than one dye molecule of opposite charge in acid solutions, in a process of reversible denaturation that can be utilized for protein fractionation. In order to understand what occurs before the co-precipitation, a kinetic study using bovine Ă-trypsin and sodium flavianate was carried out based on reaction progress curve techniques. The experiments were carried out using <FONT FACE="Symbol">a</font>-CBZ-L-Lys-p-nitrophenyl ester as substrate which was added to 50 mM sodium citrate buffer, pH 3.0, containing varying concentrations of Ă-trypsin and dye. The reaction was recorded spectrophotometrically at 340 nm for 30 min, and the families of curves obtained were analyzed simultaneously by fitting integrated Michaelis-Menten equations. The dye used behaved as a competitive inhibitor of trypsin at pH 3.0, with Ki = 99 ”M; kinetic parameters for the substrate hydrolysis were: Km = 32 ”M, and kcat = 0.38/min. The competitive character of the inhibition suggests a specific binding of the first dye molecule to His-57, the only positively charged residue at the active site of the enzyme
XX Semana de la Enseñanza de la FĂsica
25 a 29 de septiembre de 2017Facultad de Ciencias y EducaciĂłnProyecto Curricular de Licenciatura en FĂsicaUniversidad Distrital Francisco JosĂ© de Calda