title: Influence of osmolytes on protein and water structure: a step to understanding the mechanism of protein stabilization.
abstract: Results concerning the thermostability of hen egg white lysozyme in aqueous solutions with stabilizing osmolytes, trimethylamine-N-oxide (TMAO), glycine (Gly), and its N-methyl derivatives, N-methylglycine (NMG), N,N-dimethylglycine (DMG), and N,N,N-trimethylglycine (betaine, TMG), have been presented. The combination of spectroscopic (IR) and calorimetric (DSC) data allowed us to establish a link between osmolytes' influence on water structure and their ability to thermally stabilize protein molecule. Structural and energetic characteristics of stabilizing osmolytes' and lysozyme's hydration water appear to be very similar. The osmolytes increase lysozyme stabilization in the order bulk water < TMAO < TMG < Gly < DMG < NMG, which is consistent with the order corresponding to the value of the most probable oxygen-oxygen distance of water molecules affected by osmolytes in their surrounding. Obtained results verified the hypothesis concerning the role of water molecules in protein stabilization, explained the osmophobic effect, and finally helped to bring us nearer to the exact mechanism of protein stabilization by osmolytes.
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.forename: Aneta
authors.initials: A
authors.lastname: Panuszko
authors.forename: Janusz
authors.initials: J
authors.lastname: Stangret
mesh_terms: D000588:Amines / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D001622:Betaine / Q000737:chemistry; D002151:Calorimetry; D002645:Chickens; D004527:Egg Proteins / Q000737:chemistry*; D005260:Female; D005998:Glycine / Q000737:chemistry; D008744:Methylamines / Q000737:chemistry; D009113:Muramidase / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D011489:Protein Denaturation; D055550:Protein Stability; D017433:Protein Structure, Secondary; D012521:Sarcosine / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D044366:Transition Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D000588:Amines; D000596:Amino Acids; D004527:Egg Proteins; D008744:Methylamines; D012996:Solutions; D014867:Water; D001622:Betaine; D009113:Muramidase; C005855:trimethyloxamine; D010100:Oxygen; D005998:Glycine; D012521:Sarcosine