Sucralose Destabilization of Protein Structure.
Sucralose is a commonly employed artificial sweetener that behaves very differently than its natural disaccharide counterpart, sucrose, in terms of its interaction with biomolecules. The presence of sucralose in solution is found to destabilize the native structure of two model protein systems: the globular protein bovine serum albumin and an enzyme staphylococcal nuclease. The melting temperature of these proteins decreases as a linear function of sucralose concentration. We correlate this destabilization to the increased polarity of the molecule. The strongly polar nature is manifested as a large dielectric friction exerted on the excited-state rotational diffusion of tryptophan using time-resolved fluorescence anisotropy. Tryptophan exhibits rotational diffusion proportional to the measured bulk viscosity for sucrose solutions over a wide range of concentrations, consistent with a Stokes-Einstein model. For sucralose solutions, however, the diffusion is dependent on the concentration, strongly diverging from the viscosity predictions, and results in heterogeneous rotational diffusion.
†Department of Physics, Wesleyan University, 265 Church Street, Middletown, Connecticut 06459, United States.
Lee
L
Chen
†Department of Physics, Wesleyan University, 265 Church Street, Middletown, Connecticut 06459, United States.
Nimesh
N
Shukla
†Department of Physics, Wesleyan University, 265 Church Street, Middletown, Connecticut 06459, United States.
Inha
I
Cho
‡Department of Chemistry, Wesleyan University, 52 Lawn Avenue, Middletown, Connecticut 06459, United States.
Erin
E
Cohn
‡Department of Chemistry, Wesleyan University, 52 Lawn Avenue, Middletown, Connecticut 06459, United States.
Erika A
EA
Taylor
†Department of Physics, Wesleyan University, 265 Church Street, Middletown, Connecticut 06459, United States.
Christina M
CM
Othon
D008836:Micrococcal Nuclease / Q000737:chemistry; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013395:Sucrose / Q000031:analogs & derivatives* / Q000737:chemistry
D011506:Proteins; D012710:Serum Albumin, Bovine; D013395:Sucrose; C026285:trichlorosucrose; D008836:Micrococcal Nuclease
Stokes−Einstein−Debye diffusion; circular dichroism; disaccharide; fractional Stokes−Einstein−Debye; heterogeneous diffusion; protein stability; rotational correlation time; rotational diffusion; sucralose; sucrose; time-resolved fluorescence anisotropy