Cold Denaturation of Proteins

Abstract

By taking advantage of the phase behavior of water, high pressure can significantly lower the freezing point of an aqueous protein solution. In this way, using high-resolution, high-pressure NMR techniques, one can investigate not only pressure denaturation but also cold denaturation of proteins.After an overview of compression effects on dynamic and hydrodynamic behavior of water and heavy water at subzero temperatures, the main part of this contribution is devoted to selected results from recent pressure and cold denaturation NMR studies of Ribonuclease A. The cold denatured state of Ribonuclease A contains partial secondary structures in contrast to its thermally denatured state which contains little or no stable hydrogen bond structures. It was interesting to find that the pattern of protection factors for the pressure and cold denatured states of Ribonuclease A obtained by hydrogen exchange experiments parallels the pattern of protection factors for the folding intermediate of Ribonuclease A reported by Udgoaonkar and Baldwin on the basis of their pulsed hydrogen experiments.Increasing attention has recently been focused on denatured and partially folded states, since determination of their structure and stability .may provide novel information for the mechanisms of protein folding (1-3). The native conformations of hundreds of proteins are known in great detail from structural determinations by X-ray crystallography and, more recently, NMR spectroscopy. However, a detailed knowledge of the conformations of denatured and partially folded states is lacking, and represents a serious shortcoming in current studies of protein stability and protein folding pathways (2).Protein folding, the relationship between the amino acid sequence and the 310

Possible Mechanism for Cold Denaturation of Proteins at High Pressure

“…We find that above the pressure where water freezes to the dense ice phase (≈ 2 kbar), the mechanism for cold denaturation with decreasing temperature is the loss of local low-density water structure. We find our results in agreement with data of bovine pancreatic ribonuclease A.Some proteins become thermodynamically unstable at low temperatures, a phenomenon called cold denaturation [1,2,3]. This phenomenon has been mainly observed at high pressures, ranging from approximately 200 MPa up to 700 MPa [4].…”

“…Some proteins become thermodynamically unstable at low temperatures, a phenomenon called cold denaturation [1,2,3]. This phenomenon has been mainly observed at high pressures, ranging from approximately 200 MPa up to 700 MPa [4].…”

Proteomic Analysis and qRT-PCR Verification of Temperature Response to Arthrospira (Spirulina) platensis

“…The decreasing photochemical activity of PSII results from oxygen-evolving complex inactivation of PSII, structural changes in the thylakoid membranes [ 45 ], decreasing of the PSII-mediated electronic transfer rate, and changes of the antenna system conformation by high temperature. On the other hand, cyanobacteria increase the separation between the PBS supermolecules and the thylakoid membrane, which further prompts the disintegration of PBS supermolecules [ 46 ]. The expression level of linking polypeptides CpcC and CpcG significantly increased when compared to the control, which demonstrated that ASP took control measures to prevent phycobilisomes from dissociation due to high or low temperatures.…”

Mechanism for proteins destabilization at low temperatures

“…At low temperatures and high pressures (ranging from approximately 200 MPa up to 700 MPa) some proteins become thermodynamically unstable by means of a phenomenon known as cold denaturation [1][2][3][4][5]. An explanation of the P-T phase diagram of a protein with cold denaturation has been proposed [6][7][8], but a microscopic understanding of the mechanisms leading to cold denaturation has yet to be developed, due in part to the complexity of protein-solvent interactions.…”