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Hydrophobic effect on the stability and folding of a hyperthermophilic protein.
J Mol Biol. 2008 Apr 18; 378(1):264-72.JM

Abstract

Ribonuclease HII from hyperthermophile Thermococcus kodakaraensis (Tk-RNase HII) is a kinetically robust monomeric protein. The conformational stability and folding kinetics of Tk-RNase HII were measured for nine mutant proteins in which a buried larger hydrophobic side chain is replaced by a smaller one (Leu/Ile to Ala). The mutant proteins were destabilized by 8.9 to 22.0 kJ mol(-1) as compared with the wild-type protein. The removal of each -CH(2)- group burial decreased the stability by 5.1 kJ mol(-1) on average in the mutant proteins of Tk-RNase HII examined. This is comparable with the value of 5.3 kJ mol(-1) obtained from experiments for proteins from organisms growing at moderate temperature. We conclude that the hydrophobic residues buried inside protein molecules contribute to the stabilization of hyperthermophilic proteins to a similar extent as proteins at normal temperature. In the folding experiments, the mutant proteins of Tk-RNase HII examined exhibited faster unfolding compared with the wild-type protein. These results indicate that the buried hydrophobic residues strongly contribute to the kinetic robustness of Tk-RNase HII. This is the first report that provides a practical cause of slow unfolding of hyperthermostable proteins.

Authors+Show Affiliations

Department of Material and Life Science, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18353366

Citation

Dong, Hongju, et al. "Hydrophobic Effect On the Stability and Folding of a Hyperthermophilic Protein." Journal of Molecular Biology, vol. 378, no. 1, 2008, pp. 264-72.
Dong H, Mukaiyama A, Tadokoro T, et al. Hydrophobic effect on the stability and folding of a hyperthermophilic protein. J Mol Biol. 2008;378(1):264-72.
Dong, H., Mukaiyama, A., Tadokoro, T., Koga, Y., Takano, K., & Kanaya, S. (2008). Hydrophobic effect on the stability and folding of a hyperthermophilic protein. Journal of Molecular Biology, 378(1), 264-72. https://doi.org/10.1016/j.jmb.2008.02.039
Dong H, et al. Hydrophobic Effect On the Stability and Folding of a Hyperthermophilic Protein. J Mol Biol. 2008 Apr 18;378(1):264-72. PubMed PMID: 18353366.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Hydrophobic effect on the stability and folding of a hyperthermophilic protein. AU - Dong,Hongju, AU - Mukaiyama,Atsushi, AU - Tadokoro,Takashi, AU - Koga,Yuichi, AU - Takano,Kazufumi, AU - Kanaya,Shigenori, Y1 - 2008/03/04/ PY - 2007/12/18/received PY - 2008/02/09/revised PY - 2008/02/18/accepted PY - 2008/3/21/pubmed PY - 2008/5/15/medline PY - 2008/3/21/entrez SP - 264 EP - 72 JF - Journal of molecular biology JO - J Mol Biol VL - 378 IS - 1 N2 - Ribonuclease HII from hyperthermophile Thermococcus kodakaraensis (Tk-RNase HII) is a kinetically robust monomeric protein. The conformational stability and folding kinetics of Tk-RNase HII were measured for nine mutant proteins in which a buried larger hydrophobic side chain is replaced by a smaller one (Leu/Ile to Ala). The mutant proteins were destabilized by 8.9 to 22.0 kJ mol(-1) as compared with the wild-type protein. The removal of each -CH(2)- group burial decreased the stability by 5.1 kJ mol(-1) on average in the mutant proteins of Tk-RNase HII examined. This is comparable with the value of 5.3 kJ mol(-1) obtained from experiments for proteins from organisms growing at moderate temperature. We conclude that the hydrophobic residues buried inside protein molecules contribute to the stabilization of hyperthermophilic proteins to a similar extent as proteins at normal temperature. In the folding experiments, the mutant proteins of Tk-RNase HII examined exhibited faster unfolding compared with the wild-type protein. These results indicate that the buried hydrophobic residues strongly contribute to the kinetic robustness of Tk-RNase HII. This is the first report that provides a practical cause of slow unfolding of hyperthermostable proteins. SN - 1089-8638 UR - https://www.unboundmedicine.com/medline/citation/18353366/Hydrophobic_effect_on_the_stability_and_folding_of_a_hyperthermophilic_protein_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0022-2836(08)00236-2 DB - PRIME DP - Unbound Medicine ER -