TY - JOUR
T1 - Real-time monitoring of hydrophobic aggregation reveals a critical role of cooperativity in hydrophobic effect
AU - Jiang, Liguo
AU - Cao, Siqin
AU - Cheung, Peter Pak Hang
AU - Zheng, Xiaoyan
AU - Leung, Chris Wai Tung
AU - Peng, Qian
AU - Shuai, Zhigang
AU - Tang, Ben Zhong
AU - Yao, Shuhuai
AU - Huang, Xuhui
N1 - Publisher Copyright:
© The Author(s) 2017.
PY - 2017/5/31
Y1 - 2017/5/31
N2 - The hydrophobic interaction drives nonpolar solutes to aggregate in aqueous solution, and hence plays a critical role in many fundamental processes in nature. An important property intrinsic to hydrophobic interaction is its cooperative nature, which is originated from the collective motions of water hydrogen bond networks surrounding hydrophobic solutes. This property is widely believed to enhance the formation of hydrophobic core in proteins. However, cooperativity in hydrophobic interactions has not been successfully characterized by experiments. Here, we quantify cooperativity in hydrophobic interactions by real-time monitoring the aggregation of hydrophobic solute (hexaphenylsilole, HPS) in a microfluidic mixer. We show that association of a HPS molecule to its aggregate in water occurs at sub-microsecond, and the free energy change is -5.8 to -13.6 kcal mol-1. Most strikingly, we discover that cooperativity constitutes up to 40% of this free energy. Our results provide quantitative evidence for the critical role of cooperativity in hydrophobic interactions.
AB - The hydrophobic interaction drives nonpolar solutes to aggregate in aqueous solution, and hence plays a critical role in many fundamental processes in nature. An important property intrinsic to hydrophobic interaction is its cooperative nature, which is originated from the collective motions of water hydrogen bond networks surrounding hydrophobic solutes. This property is widely believed to enhance the formation of hydrophobic core in proteins. However, cooperativity in hydrophobic interactions has not been successfully characterized by experiments. Here, we quantify cooperativity in hydrophobic interactions by real-time monitoring the aggregation of hydrophobic solute (hexaphenylsilole, HPS) in a microfluidic mixer. We show that association of a HPS molecule to its aggregate in water occurs at sub-microsecond, and the free energy change is -5.8 to -13.6 kcal mol-1. Most strikingly, we discover that cooperativity constitutes up to 40% of this free energy. Our results provide quantitative evidence for the critical role of cooperativity in hydrophobic interactions.
UR - https://www.scopus.com/pages/publications/85019971408
U2 - 10.1038/ncomms15639
DO - 10.1038/ncomms15639
M3 - Article
C2 - 28561067
AN - SCOPUS:85019971408
SN - 2041-1723
VL - 8
JO - Nature Communications
JF - Nature Communications
M1 - 15639
ER -