Contribution of proton linkage to the thermodynamic stability of the major cold-shock protein of Escherichia coli CspA.


Abstract

The stability of protein is defined not only by the hydrogen bonding, hydrophobic effect, van der Waals interactions, and salt bridges. Additional, much more subtle contributions to protein stability can arise from surface residues that change their properties upon unfolding. The recombinant major cold shock protein of Escherichia coli CspA an all-beta protein unfolds reversible in a two-state manner, and behaves in all other respects as typical globular protein. However, the enthalpy of CspA unfolding strongly depends on the pH and buffer composition. Detailed analysis of the unfolding enthalpies as a function of pH and buffers with different heats of ionization shows that CspA unfolding in the pH range 5.5-9.0 is linked to protonation of an amino group. This amino group appears to be the N-terminal alpha-amino group of the CspA molecule. It undergoes a 1.6 U shift in pKa values between native and unfolded states. Although this shift in pKa is expected to contribute approximately 5 kJ/mol to CspA stabilization energy the experimentally observed stabilization is only approximately 1 kJ/mol. This discrepancy is related to a strong enthalpy-entropy compensation due, most likely, to the differences in hydration of the protonated and deprotonated forms of the alpha-amino group. Study holds ProTherm entries: 9530, 9531, 9532, 9533, 9534, 9535, 9536, 9537, 9538, 9539, 9540, 9541, 9542, 9543, 9544, 9545, 9546, 9547, 9548, 9549, 9550, 9551, 9552, 9553, 9554, 9555, 9556, 9557, 9558, 9559, 9560, 9561, 9562, 9563, 9564, 9565 Extra Details: cold-shock protein; escherichia coli CspA; hydrogen bonding;,hydorophobic effect; proton linkage

Submission Details

ID: QuszxfNM

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:38 p.m.

Version: 1

Publication Details
Petrosian SA;Makhatadze GI,Protein Sci. (2000) Contribution of proton linkage to the thermodynamic stability of the major cold-shock protein of Escherichia coli CspA. PMID:10716191
Additional Information

Number of data points 72
Proteins Cold shock protein CspA ; Cold shock protein CspA
Unique complexes 1
Assays/Quantities/Protocols Experimental Assay: dHcal buffers:imidazole: 10 mM, pH:8.0 ; Experimental Assay: Tm buffers:imidazole: 10 mM, pH:8.0 ; Experimental Assay: dHcal pH:7.5, buffers:imidazole: 10 mM ; Experimental Assay: Tm pH:7.5, buffers:imidazole: 10 mM ; Experimental Assay: dHcal buffers:imidazole: 10 mM, pH:7.0 ; Experimental Assay: Tm buffers:imidazole: 10 mM, pH:7.0 ; Experimental Assay: dHcal buffers:imidazole: 10 mM, pH:6.5 ; Experimental Assay: Tm buffers:imidazole: 10 mM, pH:6.5 ; Experimental Assay: dHcal buffers:MOPS: 10 mM, pH:8.0 ; Experimental Assay: Tm buffers:MOPS: 10 mM, pH:8.0 ; Experimental Assay: dHcal pH:7.5, buffers:MOPS: 10 mM ; Experimental Assay: Tm pH:7.5, buffers:MOPS: 10 mM ; Experimental Assay: dHcal buffers:MOPS: 10 mM, pH:7.0 ; Experimental Assay: Tm buffers:MOPS: 10 mM, pH:7.0 ; Experimental Assay: dHcal buffers:MOPS: 10 mM, pH:6.5 ; Experimental Assay: Tm buffers:MOPS: 10 mM, pH:6.5 ; Experimental Assay: dHcal pH:6.0, buffers:MOPS: 10 mM ; Experimental Assay: Tm pH:6.0, buffers:MOPS: 10 mM ; Experimental Assay: dHcal pH:7.5, buffers:PIPES: 10 mM ; Experimental Assay: Tm pH:7.5, buffers:PIPES: 10 mM ; Experimental Assay: dHcal buffers:PIPES: 10 mM, pH:7.0 ; Experimental Assay: Tm buffers:PIPES: 10 mM, pH:7.0 ; Experimental Assay: dHcal buffers:PIPES: 10 mM, pH:6.5 ; Experimental Assay: Tm buffers:PIPES: 10 mM, pH:6.5 ; Experimental Assay: dHcal pH:6.0, buffers:PIPES: 10 mM ; Experimental Assay: Tm pH:6.0, buffers:PIPES: 10 mM ; Experimental Assay: dHcal pH:8.7, buffers:Sodium borate: 10 mM ; Experimental Assay: Tm pH:8.7, buffers:Sodium borate: 10 mM ; Experimental Assay: dHcal pH:8.5, buffers:Sodium borate: 10 mM ; Experimental Assay: Tm pH:8.5, buffers:Sodium borate: 10 mM ; Experimental Assay: dHcal pH:7.5, buffers:Sodium citrate: 10 mM ; Experimental Assay: Tm pH:7.5, buffers:Sodium citrate: 10 mM ; Experimental Assay: dHcal buffers:Sodium citrate: 10 mM, pH:7.0 ; Experimental Assay: Tm buffers:Sodium citrate: 10 mM, pH:7.0 ; Experimental Assay: dHcal buffers:Sodium citrate: 10 mM, pH:6.5 ; Experimental Assay: Tm buffers:Sodium citrate: 10 mM, pH:6.5 ; Experimental Assay: dHcal pH:6.0, buffers:Sodium citrate: 10 mM ; Experimental Assay: Tm pH:6.0, buffers:Sodium citrate: 10 mM ; Experimental Assay: dHcal buffers:HEPES: 10 mM, pH:8.5 ; Experimental Assay: Tm buffers:HEPES: 10 mM, pH:8.5 ; Experimental Assay: dHcal buffers:HEPES: 10 mM, pH:8.0 ; Experimental Assay: Tm buffers:HEPES: 10 mM, pH:8.0 ; Experimental Assay: dHcal pH:7.5, buffers:HEPES: 10 mM ; Experimental Assay: Tm pH:7.5, buffers:HEPES: 10 mM ; Experimental Assay: dHcal buffers:HEPES: 10 mM, pH:7.0 ; Experimental Assay: Tm buffers:HEPES: 10 mM, pH:7.0 ; Experimental Assay: dHcal buffers:HEPES: 10 mM, pH:6.5 ; Experimental Assay: Tm buffers:HEPES: 10 mM, pH:6.5 ; Experimental Assay: dHcal pH:7.5, buffers:Sodium phosphate: 10 mM ; Experimental Assay: Tm pH:7.5, buffers:Sodium phosphate: 10 mM ; Experimental Assay: dHcal buffers:Sodium phosphate: 10 mM, pH:7.0 ; Experimental Assay: Tm buffers:Sodium phosphate: 10 mM, pH:7.0 ; Experimental Assay: dHcal buffers:Sodium phosphate: 10 mM, pH:6.5 ; Experimental Assay: Tm buffers:Sodium phosphate: 10 mM, pH:6.5 ; Experimental Assay: dHcal pH:6.0, buffers:Sodium phosphate: 10 mM ; Experimental Assay: Tm pH:6.0, buffers:Sodium phosphate: 10 mM ; Experimental Assay: dHcal buffers:Sodium cacodylate: 10 mM, pH:7.0 ; Experimental Assay: Tm buffers:Sodium cacodylate: 10 mM, pH:7.0 ; Experimental Assay: dHcal buffers:Sodium cacodylate: 10 mM, pH:6.5 ; Experimental Assay: Tm buffers:Sodium cacodylate: 10 mM, pH:6.5 ; Experimental Assay: dHcal pH:6.0, buffers:Sodium cacodylate: 10 mM ; Experimental Assay: Tm pH:6.0, buffers:Sodium cacodylate: 10 mM ; Experimental Assay: dHcal pH:5.5, buffers:Sodium cacodylate: 10 mM ; Experimental Assay: Tm pH:5.5, buffers:Sodium cacodylate: 10 mM ; Experimental Assay: dHcal buffers:Sodium acetate: 10 mM, pH:5.5 ; Experimental Assay: Tm buffers:Sodium acetate: 10 mM, pH:5.5 ; Experimental Assay: dHcal buffers:Sodium acetate: 10 mM, pH:5.0 ; Experimental Assay: Tm buffers:Sodium acetate: 10 mM, pH:5.0 ; Experimental Assay: dHcal buffers:Sodium acetate: 10 mM, pH:4.5 ; Experimental Assay: Tm buffers:Sodium acetate: 10 mM, pH:4.5 ; Experimental Assay: dHcal buffers:Sodium acetate: 10 mM, pH:4.0 ; Experimental Assay: Tm buffers:Sodium acetate: 10 mM, pH:4.0
Libraries Mutations for sequence SGKMTGIVKWFNADKGFGFITPDDGSKDVFVHFSAIQNDGYKSLDEGQKVSFTIESGAKGPAAGNVTSL
Sequence Assay Result Units