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Structure and excited-state proton transfer in the GFP S205A mutant.
J Phys Chem B. 2011 Oct 20; 115(41):11776-85.JP

Abstract

To further explore excited state proton transfer (ESPT) pathways within green fluorescent protein (GFP), mutagenesis, X-ray crystallography, and time-resolved and steady-state optical spectroscopy were employed to create and study the GFP mutant S205A. In wild type GFP (wt-GFP), the proton transfer pathway includes the hydroxyl group of the chromophore, a water molecule, Ser205, and Glu222. We found that the ESPT rate constant of S205A is smaller by a factor of 20 than that of wt-GFP and larger by a factor of 2 in comparison to the ESPT rate of S205V mutant which we previously characterized. (1) High resolution crystal structures reveal that in both S205A and S205V mutants, an alternative proton transfer pathway is formed that involves the chromophore hydroxyl, a bridging water molecule, Thr203 and Glu222. The slow PT rate is explained by the long (∼3.2 Å and presumably weak) hydrogen bond between Thr203 and the water molecule, compared to the 2.7 Å normal hydrogen bond between the water molecule and Ser205 in wt-GFP. For data analysis of the experimental data from both GFP mutants, we used a two-rotamer kinetic model, assuming only one rotamer is capable of ESPT. Data analysis supports an agreement with the underlying assumption of this model.

Authors+Show Affiliations

Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry Tel Aviv University, Tel Aviv 69978, Israel.No affiliation info availableNo 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
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

21902228

Citation

Erez, Yuval, et al. "Structure and Excited-state Proton Transfer in the GFP S205A Mutant." The Journal of Physical Chemistry. B, vol. 115, no. 41, 2011, pp. 11776-85.
Erez Y, Gepshtein R, Presiado I, et al. Structure and excited-state proton transfer in the GFP S205A mutant. J Phys Chem B. 2011;115(41):11776-85.
Erez, Y., Gepshtein, R., Presiado, I., Trujillo, K., Kallio, K., Remington, S. J., & Huppert, D. (2011). Structure and excited-state proton transfer in the GFP S205A mutant. The Journal of Physical Chemistry. B, 115(41), 11776-85. https://doi.org/10.1021/jp2052689
Erez Y, et al. Structure and Excited-state Proton Transfer in the GFP S205A Mutant. J Phys Chem B. 2011 Oct 20;115(41):11776-85. PubMed PMID: 21902228.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Structure and excited-state proton transfer in the GFP S205A mutant. AU - Erez,Yuval, AU - Gepshtein,Rinat, AU - Presiado,Itay, AU - Trujillo,Kristina, AU - Kallio,Karen, AU - Remington,S James, AU - Huppert,Dan, Y1 - 2011/09/28/ PY - 2011/9/10/entrez PY - 2011/9/10/pubmed PY - 2012/2/16/medline SP - 11776 EP - 85 JF - The journal of physical chemistry. B JO - J Phys Chem B VL - 115 IS - 41 N2 - To further explore excited state proton transfer (ESPT) pathways within green fluorescent protein (GFP), mutagenesis, X-ray crystallography, and time-resolved and steady-state optical spectroscopy were employed to create and study the GFP mutant S205A. In wild type GFP (wt-GFP), the proton transfer pathway includes the hydroxyl group of the chromophore, a water molecule, Ser205, and Glu222. We found that the ESPT rate constant of S205A is smaller by a factor of 20 than that of wt-GFP and larger by a factor of 2 in comparison to the ESPT rate of S205V mutant which we previously characterized. (1) High resolution crystal structures reveal that in both S205A and S205V mutants, an alternative proton transfer pathway is formed that involves the chromophore hydroxyl, a bridging water molecule, Thr203 and Glu222. The slow PT rate is explained by the long (∼3.2 Å and presumably weak) hydrogen bond between Thr203 and the water molecule, compared to the 2.7 Å normal hydrogen bond between the water molecule and Ser205 in wt-GFP. For data analysis of the experimental data from both GFP mutants, we used a two-rotamer kinetic model, assuming only one rotamer is capable of ESPT. Data analysis supports an agreement with the underlying assumption of this model. SN - 1520-5207 UR - https://www.unboundmedicine.com/medline/citation/21902228/Structure_and_excited_state_proton_transfer_in_the_GFP_S205A_mutant_ L2 - https://doi.org/10.1021/jp2052689 DB - PRIME DP - Unbound Medicine ER -