TY - JOUR
T1 - Tardigrade Secretory-Abundant Heat-Soluble Protein Has a Flexible β-Barrel Structure in Solution and Keeps This Structure in Dehydration
AU - Miyazawa, Kazuhisa
AU - Itoh, Satoru G.
AU - Watanabe, Hiroki
AU - Uchihashi, Takayuki
AU - Yanaka, Saeko
AU - Yagi-Utsumi, Maho
AU - Kato, Koichi
AU - Arakawa, Kazuharu
AU - Okumura, Hisashi
N1 - Funding Information:
The computations were performed using the supercomputer of the Research Center for Computational Science, Okazaki, Japan. This research was supported by Joint Research by Exploratory Research Center on Life and Living Systems (ExCELLS). (ExCELLS program nos. 18-101, 19-208, and 19-501).
Publisher Copyright:
© 2021 American Chemical Society. All rights reserved.
PY - 2021/8/19
Y1 - 2021/8/19
N2 - Secretory-abundant heat-soluble (SAHS) proteins are unique heat-soluble proteins of Tardigrada and are believed to play an essential role in anhydrobiosis, a latent state of life induced by desiccation. To investigate the dynamic properties, molecular dynamics (MD) simulations of a SAHS protein, RvSAHS1, were performed in solution and under dehydrating conditions. For comparison purposes, MD simulations of a human liver-type fatty-acid binding protein (LFABP) were performed in solution. Furthermore, high-speed atomic force microscopy observations were conducted to ascertain the results of the MD simulations. Three properties of RvSAHS1 were found as follows. (1) The entrance region of RvSAHS1 is more flexible and can be more extensive in solutions compared with that of a human LFABP because there is no salt bridge between the βD and βE strands. (2) The intrinsically disordered domain in the N-terminal region significantly fluctuates and can form an amphiphilic α-helix. (3) The size of the entrance region gets smaller along with dehydration, keeping the β-barrel structure. Overall, the obtained results provide atomic-level dynamics of SAHS proteins.
AB - Secretory-abundant heat-soluble (SAHS) proteins are unique heat-soluble proteins of Tardigrada and are believed to play an essential role in anhydrobiosis, a latent state of life induced by desiccation. To investigate the dynamic properties, molecular dynamics (MD) simulations of a SAHS protein, RvSAHS1, were performed in solution and under dehydrating conditions. For comparison purposes, MD simulations of a human liver-type fatty-acid binding protein (LFABP) were performed in solution. Furthermore, high-speed atomic force microscopy observations were conducted to ascertain the results of the MD simulations. Three properties of RvSAHS1 were found as follows. (1) The entrance region of RvSAHS1 is more flexible and can be more extensive in solutions compared with that of a human LFABP because there is no salt bridge between the βD and βE strands. (2) The intrinsically disordered domain in the N-terminal region significantly fluctuates and can form an amphiphilic α-helix. (3) The size of the entrance region gets smaller along with dehydration, keeping the β-barrel structure. Overall, the obtained results provide atomic-level dynamics of SAHS proteins.
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U2 - 10.1021/acs.jpcb.1c04850
DO - 10.1021/acs.jpcb.1c04850
M3 - Article
C2 - 34375104
AN - SCOPUS:85113992612
SN - 1520-6106
VL - 125
SP - 9145
EP - 9154
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 32
ER -