Protein expression using Escherichia coli is a common and important method for recombinant protein production. Herein, we quantitatively analyzed the correlation between protein expression in vivo and thermodynamic structure stability in vitro using the tetramerization domain of tumor suppressor protein p53. We found a strong positive relationship between the expression level and the thermodynamic stability. Our study suggests that a minimum thermodynamic stability of a protein is required for substantial protein expression in bacterial cells.