Thermal stability of Bizionia argentinensis CopA, a psychrophilic PIB-ATPase

NOELIA A. MELIAN; NOELIA I. BURGARDT; LUIS GONZALEZ FLECHA

Buenos Aires

Congreso; Protein Biophysics at the end of the world; 2017

Membrane proteins (MPs) represent about 30 % of total proteins codified in known genomes1. Although MPs play a key role in many critical biological processes, there are few works reporting structural, functional and thermodynamic data of these proteins2. Our main interest is to study the relationships between membrane protein folding, function and stability. To achieve this, we choose the PIB-ATPase family as model, they are integral membrane proteins which actively transport heavy metal ions through the cell membrane in association with ATP hydrolysis3. Previously, we have investigated the unfolding of the thermophilic PIB-ATPase from Archaeglobus fulgidus by thermal denaturation4. Recently we cloned a PIB-ATPase from the psychrophilic bacteria Bizionia argentinensis (BaCopA)5,6. After heterologous expression in S. cerevisiae, purification and reconstitution in mixed micelles, BaCopA retained catalytic function6. In this work, we characterized the thermal stability of this enzyme, exploring the kinetics of BaCopA thermal inactivation process and its dependence with temperature.1. Wallin E, et al. Protein Sci. 7:1029-1038, 1998.  2. Roman EA, et al. Biomolecules. 4:354-73, 2014.3. Rensing C, et al. J Bacteriol 181:5891-5897, 1999.4. Cattoni DI, et al. Arch Biochem Biophys. 471:198-206, 2008.5. Bercovich A, et al. Int J Syst Evol Microbiol. 58:2363-2367, 2008.6. Burgardt NI, et al. Manuscript in preparation, 2017