Antarctic yeasts as a source of L-asparaginase: Characterization of a glutaminase-activity free L-asparaginase from psychrotolerant yeast Leucosporidium scottii L115

Autor(es):Mostrar menos -

Sanchez-Moguel, Ignacio ; Costa-Silva, Tales A. ; Pillaca-Pullo, Omar S. ; Flores-Santos, Juan Carlos ; Barros Freire, Rominne Karla ; Carretero, Gustavo ; Bueno, Julia da Luz ; Camacho-Cordova, David I. ; Santos, Joao H. P. M. ; Sette, Lara Duraes ; Pessoa-, Adalberto, Jr.

• Tipo de documento: Artigo Científico
• Fonte: Process Biochemistry; v. 129, p. 12-pg., 2023-03-21.

Resumo

Microorganisms from extreme environments, such as the Antarctic ecosystems, have a great potential to produce enzymes with novel characteristics. Within this context, L-asparaginase (ASNase) obtained from yeast species has been poorly studied. In this study, yeasts isolated from samples collected at Admiralty Bay (King George Island, Antarctica) were tested to produce ASNase. From an initial screening of 40 strains, belonging to 13 different species, Leucosporidium scottii L115 produced an ASNase activity (LsASNase activity: 6.24 U g-1 of dry cell weight) with the lowest glutaminase activity. The LsASNase was purified 227-fold, with a specific activity of 137.01 U mg-1 at 37 degrees C, without glutaminase activity. Moreover, the maximum enzyme activity was observed at pH 7.5 and at a temperature of 55 degrees C. The enzyme is a multimer of 462 kDa, presenting a single band of 53 kDa mo-lecular mass in reduced conditions; after PGNase F treatment, a single band of 45 kDa was observed. The enzymatic kinetic evaluation revealed an allosteric regulation of the enzyme and the kinetic parameters were determined at 37 degrees C, pH 7.0 as substrate affinity constant, K0.5 = 233 mu M, kcat = 54.7 s-1 and Hill coefficient, nH = 1.52, demonstrating positive cooperativity by the enzyme and the substrate. This is the first study to report L. scottii as a source of glutaminase-activity free L-asparaginase, an acute lymphoblastic leukemia drug feature suitable for the treatment of asparagine synthetase negative cancer cells. (AU)

• Processo FAPESP: 19/23620-0 - Produção de L-asparaginase de origem fúngica em formulação estável para tratamento antileucêmico
• Beneficiário: Adalberto Pessoa Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/19584-2 - Produção de L-asparaginase extracelular pelo fungo Arpergillus terreus
• Beneficiário: Tales Alexandre da Costa e Silva
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/08617-7 - Produção de L-asparaginase extracelular: da bioprospecção à engenharia de um biofármaco antileucêmico
• Beneficiário: Adalberto Pessoa Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático