Purification and biochemical characterization of an extracellular serine peptidase from Aspergillus terreus

• Autor(a) principal: Biaggio, Rafael Tage
• Data de Publicação: 2016
• Outros Autores: Silva, Ronivaldo Rodrigues da [UNESP], Rosa, Nathalia Gonsales da, Ribeiro Leite, Rodrigo Simoes, Arantes, Eliane Candiani, Freitas Cabral, Tatiana Pereira de, Juliano, Maria A., Juliano, Luiz, Cabral, Hamilton
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1080/10826068.2015.1031387; http://hdl.handle.net/11449/158832
• topic: Aspergillus; enzyme kinetics; filamentous fungi; N-terminal sequence; protease; protein

Peptidases are important because they play a central role in pharmaceutical, food, environmental, and other industrial processes. A serine peptidase from Aspergillus terreus was isolated after two chromatography steps that showed a yield of 15.5%. Its molecular mass was determined to be 43 kD, by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). This peptidase was active between pH 5.0 to 8.0 and had maximum activity at pH 7.0, at 45 degrees C. When exposited with 1 M of urea, the enzyme maintained 100% activity and used azocasein as substrate. The N-terminal (first 15 residues) showed 33% identity with the serine peptidase of Aspergillus clavatus ES1. The kinetics assays showed that subsite S-2 did not bind polar basic amino acids (His and Arg) nonpolar acidic amino acids (Asp and Glu). The subsite S-1 showed higher catalytic efficiency than the S-2 and S-3 subsites.