title: General Mechanism of Osmolytes' Influence on Protein Stability Irrespective of the Type of Osmolyte Cosolvent.
abstract: The stability of proteins in an aqueous solution can be modified by the presence of osmolytes. The hydration sphere of stabilizing osmolytes is strikingly similar to the enhanced hydration sphere of a protein. This similarity leads to an increase in the protein stability. Moreover, the hydration sphere of destabilizing osmolytes is significantly different. These solutes generate in their surroundings so-called "structurally different water". The addition of such osmolytes causes "dissolution" of the specific protein hydration sphere and destabilizes its folded form. No relationship is seen between the stabilizing/destabilizing properties of osmolytes and their structure-making/-breaking influence on water. Furthermore, their accumulation at the protein surface or their exclusion does not determine the osmolytes' effect on protein stability. An explanation to the osmolytes' stabilizing/destabilizing influence originates in the similarity of water properties in osmolytes and protein solutions. The spectral infrared characteristic of water in an osmolyte solution allowed us to develop practical criteria for classifying solutes as stabilizing or destabilizing agents.
authors.affiliation: Department of Physical Chemistry, Chemical Faculty, Gdańsk University of Technology , Narutowicza 11/12, 80-233 Gdańsk, Poland.
authors.forename: Aneta
authors.initials: A
authors.lastname: Panuszko
authors.affiliation: Department of Physical Chemistry, Chemical Faculty, Gdańsk University of Technology , Narutowicza 11/12, 80-233 Gdańsk, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Bruździak
authors.affiliation: Department of Physical Chemistry, Chemical Faculty, Gdańsk University of Technology , Narutowicza 11/12, 80-233 Gdańsk, Poland.
authors.forename: Emilia
authors.initials: E
authors.lastname: Kaczkowska
authors.affiliation: Department of Physical Chemistry, Chemical Faculty, Gdańsk University of Technology , Narutowicza 11/12, 80-233 Gdańsk, Poland.
authors.forename: Janusz
authors.initials: J
authors.lastname: Stangret
mesh_terms: D009113:Muramidase / Q000737:chemistry* / Q000378:metabolism; D009994:Osmolar Concentration; D055550:Protein Stability; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000737:chemistry
chemical_list: D012996:Solutions; D014867:Water; C421864:hen egg lysozyme; D009113:Muramidase