Effects of Protein Stabilizing Agents on Thermal Backbone Motions: A Disulfide Trapping Study†

摘要: Chemical stabilizers are widely used to enhance protein stability, both in nature and the laboratory. Here, molecular mechanism of chemical is studied using a disulfide trapping assay measure effects on thermal backbone dynamics Escherichia coli galactose/glucose binding protein. Two types fluctuations examined:  (a) relative movements adjacent surface α-helices within same domain (b) interdomain twisting motions. Both significantly reduced by all six tested (glycerol, sucrose, trehalose, l-glucose, d-glucose, d-galactose), each case larger amplitude motions inhibited more than smaller ones. Motional inhibition does not require high-affinity stabilizer site, indicating that nonspecific. Overall, results support theory effective stabilizing agents act favoring most compact structure protein, thereby reducing local b...