Title:Proteomic Analysis of Intra- and Extracellular Proteins of Aspergillus Niveus During Submerged Bioprocess Culturing Under Different pH Conditions
VOLUME: 18
Author(s):Juliana Abigail Leite, Nathalia Gonsales da Rosa-Garzon, Helen Julie Laure, José Cesar Rosa, Octavio Luiz Franco, Cristina Maria de Souza Motta and Hamilton Cabral*
Affiliation:Department of Pharmaceutical Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Department of Pharmaceutical Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Department of Molecular and Cellular Biology and Pathogenic Bioagents, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Department of Molecular and Cellular Biology and Pathogenic Bioagents, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Graduate Program in Genomic Sciences and Biotechnology, Center for Proteomic and Biochemical Analysis, Catholic University of Brasilia, Brasilia, Department of Mycology, Federal University of Pernambuco, Recife, Department of Pharmaceutical Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto
Keywords:Aspergillu niveus, MALDI-TOF/TOF-MS, pH effect, proteomic, secretome, submerged bioprocess
Abstract:Background: Proteomics facilitates understanding of the complexity of molecular and physiological mechanisms
involved in the metabolic and biological fungal adaptations to pH changes. Proteomics enables the identification of enzymes
and fungal proteins involved in these adaptations. This approach may be used to investigate such fungi as Aspergillus niveus, whose proteome has not yet been analyzed, changes the intra- and extracellular protein profiles in response to extracellular pH.
Objective: In the current study, we used two-dimensional gel electrophoresis (2DE) and mass spectrometry to evaluate the
response of A. niveus to grow at pH 5, 6, 7, and 8 for 96 hours submerged bioprocess culturing.
Methods: This study evaluated the response of A. niveus to grow at pH 5, 6, 7, and 8 for 96 h submerged bioprocess culturing, by analysis of two-dimensional gel electrophoresis (2DE), of the intracellular proteomes and the secretome, protein
spots of interest were submitted to tryptic digestion and analyzed by matrix-assisted laser desorption/ionization time-offlight tandem mass spectrometry (MALDI-TOF/TOF-MS).
Results: This approach revealed substantial differences between the functions of intra- and extracellular proteins of A. niveus. The data suggested that pH-modulated global proteins are involved in important, mainly metabolic, processes, in the
pentose phosphate pathway, protein regulation, cell wall maintenance, and others. Moreover, the change in extracellular pH
could have altered the availability of nutrients, and induced the production of enzymes that respond to oxidative and other
stresses.
Conclusion: Proteomic facilitates understanding of the complexity of molecular and physiological mechanisms involved in
the metabolic and biological adaptations of fungi to pH changes.
