Modulation of the Hydrogen Bonding Structure of Water by Renal Osmolytes.
Osmolytes are an integral part of living organism, e.g., the kidney uses sorbitol, trimethylglycine, taurine and myo-inositol to counter the deleterious effects of urea and salt. Therefore, knowing that the osmolytes' act either directly to the protein or mediated through water is of great importance. Our experimental and computational results show that protecting osmolytes, e.g., trimethylglycine and sorbitol, significantly modulate the water H-bonding network structure, although the magnitude and spatial extent of osmolyte-induced perturbation greatly vary. In contrast, urea behaves neutrally toward local water H-bonding network. Protecting osmolytes studied here show strong concentration-dependent behaviors (vibrational frequencies and lifetimes of two different infrared (IR) probes), while denaturant does not. The H-bond donor and/or acceptor (OH/NH) in a given osmolyte molecule play a critical role in defining their action. Our findings highlight the significance of the alteration of H-bonding network of water under biologically relevant environment, often encountered in real biological systems.
†Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 136-701, Republic of Korea.|‡Department of Chemistry, Korea University, Seoul 136-701, Republic of Korea.
Pramod Kumar
PK
Verma
†Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 136-701, Republic of Korea.|‡Department of Chemistry, Korea University, Seoul 136-701, Republic of Korea.
Hochan
H
Lee
†Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 136-701, Republic of Korea.|‡Department of Chemistry, Korea University, Seoul 136-701, Republic of Korea.
Joon-Young
JY
Park
†Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 136-701, Republic of Korea.|‡Department of Chemistry, Korea University, Seoul 136-701, Republic of Korea.
Joon-Hyung
JH
Lim
†Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 136-701, Republic of Korea.|‡Department of Chemistry, Korea University, Seoul 136-701, Republic of Korea.
Michał
M
Maj
†Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 136-701, Republic of Korea.
Jun-Ho
JH
Choi
§Department of Chemistry, Chung-Ang University, Seoul 156-756, Republic of Korea.
Kyung-Won
KW
Kwak
†Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 136-701, Republic of Korea.|‡Department of Chemistry, Korea University, Seoul 136-701, Republic of Korea.
Minhaeng
M
Cho
MD simulation; hydrogen bonding; infrared pump−probe; orientational relaxation; population relaxation; renal osmolyte; vibrational spectroscopy