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Low-temperature spectroscopy of Met100Ala mutant of photoactive yellow protein.
Photochem Photobiol. 2008 Jul-Aug; 84(4):970-6.PP

Abstract

The trans-to-cis photoisomerization of the p-coumaroyl chromophore of photoactive yellow protein (PYP) triggers the photocycle. Met100, which is located in the vicinity of the chromophore, is a key residue for the cis-to-trans back-isomerization of the chromophore, which is a rate-determining reaction of the PYP photocycle. Here we characterized the photocycle of the Met100Ala mutant of PYP (M100A) by low temperature UV-visible spectroscopy. Irradiation of M100A at 80 K yielded a 380 nm species (M100A(BL)), while the corresponding intermediate of wild type (WT; PYP(BL)) is formed above 90 K. The amounts of redshifted intermediates produced from M100A (M100A(B') and M100A(L)) were substantially less than those from WT. While the near-UV intermediate (PYP(M)) is not formed from WT in glycerol samples at low temperature, M100A(M) was clearly observed above 190 K. These alterations of the photocycle of M100A were explained by the shift in the equilibrium between the intermediates. The carbonyl oxygen of the thioester linkage of the cis-chromophore in the photocycle intermediates is close to the phenyl ring of Phe96 (<3.5 A), which would be displaced by the mutation of Met100. These findings imply that the interaction between chromophore and amino acid residues near Met100 is altered during the early stage of the PYP photocycle.

Authors+Show Affiliations

Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan. imamoto@vision-kyoto-u.jpNo 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

18399916

Citation

Imamoto, Yasushi, et al. "Low-temperature Spectroscopy of Met100Ala Mutant of Photoactive Yellow Protein." Photochemistry and Photobiology, vol. 84, no. 4, 2008, pp. 970-6.
Imamoto Y, Harigai M, Morimoto T, et al. Low-temperature spectroscopy of Met100Ala mutant of photoactive yellow protein. Photochem Photobiol. 2008;84(4):970-6.
Imamoto, Y., Harigai, M., Morimoto, T., & Kataoka, M. (2008). Low-temperature spectroscopy of Met100Ala mutant of photoactive yellow protein. Photochemistry and Photobiology, 84(4), 970-6. https://doi.org/10.1111/j.1751-1097.2008.00336.x
Imamoto Y, et al. Low-temperature Spectroscopy of Met100Ala Mutant of Photoactive Yellow Protein. Photochem Photobiol. 2008 Jul-Aug;84(4):970-6. PubMed PMID: 18399916.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Low-temperature spectroscopy of Met100Ala mutant of photoactive yellow protein. AU - Imamoto,Yasushi, AU - Harigai,Miki, AU - Morimoto,Takashi, AU - Kataoka,Mikio, Y1 - 2008/04/09/ PY - 2008/4/11/pubmed PY - 2008/9/24/medline PY - 2008/4/11/entrez SP - 970 EP - 6 JF - Photochemistry and photobiology JO - Photochem Photobiol VL - 84 IS - 4 N2 - The trans-to-cis photoisomerization of the p-coumaroyl chromophore of photoactive yellow protein (PYP) triggers the photocycle. Met100, which is located in the vicinity of the chromophore, is a key residue for the cis-to-trans back-isomerization of the chromophore, which is a rate-determining reaction of the PYP photocycle. Here we characterized the photocycle of the Met100Ala mutant of PYP (M100A) by low temperature UV-visible spectroscopy. Irradiation of M100A at 80 K yielded a 380 nm species (M100A(BL)), while the corresponding intermediate of wild type (WT; PYP(BL)) is formed above 90 K. The amounts of redshifted intermediates produced from M100A (M100A(B') and M100A(L)) were substantially less than those from WT. While the near-UV intermediate (PYP(M)) is not formed from WT in glycerol samples at low temperature, M100A(M) was clearly observed above 190 K. These alterations of the photocycle of M100A were explained by the shift in the equilibrium between the intermediates. The carbonyl oxygen of the thioester linkage of the cis-chromophore in the photocycle intermediates is close to the phenyl ring of Phe96 (<3.5 A), which would be displaced by the mutation of Met100. These findings imply that the interaction between chromophore and amino acid residues near Met100 is altered during the early stage of the PYP photocycle. SN - 0031-8655 UR - https://www.unboundmedicine.com/medline/citation/18399916/Low_temperature_spectroscopy_of_Met100Ala_mutant_of_photoactive_yellow_protein_ L2 - https://doi.org/10.1111/j.1751-1097.2008.00336.x DB - PRIME DP - Unbound Medicine ER -