Two-pathway four-state kinetic model of thioredoxin-catalyzed reduction of single forced disulfide bonds.
Recent single-molecule experiments found that the thioredoxin-catalyzed reduction of individual disulfide bonds placed under a stretching mechanical force has distinct characteristics: the reduction rate of human thioredoxin monotonically decreases with the force, while the rate of E. coli thioredoxin first decreases and then increases as the force goes beyond a certain threshold. In this work, we present a force-dependent two-pathway four-state model to uniformly quantify these intriguing observations. Although our model is indistinguishable from the previous two-pathway three-state model in predicting the mean reduction rate, the distributions of dwell times of the two models are significantly distinctive. The very recent experiment favors our model.
Xue
Xiaochuan
X
Center for Advanced Study, Tsinghua University, Beijing 100084, China.
Gong
Linchen
L
Liu
Fei
F
Ou-Yang
Zhong-Can
ZC
D001665:Binding Sites; D002384:Catalysis; D003198:Computer Simulation; D004220:Disulfides / Q000737:chemistry*; D007700:Kinetics; D008846:Micromanipulation / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D010084:Oxidation-Reduction; D011485:Protein Binding; D011487:Protein Conformation; D013314:Stress, Mechanical; D013879:Thioredoxins / Q000737:chemistry* / Q000648:ultrastructure*
D004220:Disulfides; D013879:Thioredoxins