Citrate and phosphate influence on green fluorescent protein thermal stability

Authors

  • Letícia C. de Lencastre Novaes,

    Corresponding author
    1. Dept. of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of São Paulo, SP, Brazil
    • Dept. of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of São Paulo, SP, Brazil
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  • Priscila G. Mazzola,

    1. Dept. of Clinical Pathology, Faculty of Medical Sciences, University of Campinas, SP, Brazil
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  • Adalberto Pessoa Jr.,

    1. Dept. of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of São Paulo, SP, Brazil
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  • Thereza C. Vessoni Penna

    1. Dept. of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of São Paulo, SP, Brazil
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Abstract

Protein structure and function can be regulated by no specific interactions, such as ionic interactions in the presence of salts. Green fluorescent protein (GFP) shows remarkable structural stability and high fluorescence; its stability can be directly related to its fluorescence output, among other characteristics. GFP is stable under increasing temperatures, and its thermal denaturation is highly reproducible. The aim of this study was to evaluate the thermal stability of GFP in the presence of different salts at several concentrations and exposed to constant temperatures, in a range of 70–95°C. Thermal stability was expressed in decimal reduction time. It was observed that the D-values obtained were higher in the presence of citrate and phosphate, when compared with that obtained in their absence, indicating that these salts stabilized the protein against thermal denaturation. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2011

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