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Fluorescence and folding properties of Tyr mutant tryptophan synthase alpha-subunits from Escherichia coli.
Biochem Biophys Res Commun. 2003 Jan 03; 300(1):29-35.BB

Abstract

The fluorescence of tyrosine has been used to monitor a folding process of tryptophan synthase alpha-subunit from Escherichia coli, because this protein has 7 tyrosines, but not tryptophan. Here to assess the contribution of each Tyr to fluorescence properties of this protein during folding, mutant proteins in which Tyr was replaced with Phe were analyzed. The result shows that a change of Tyr fluorescence occurring during folding of this protein is contributed to approximately 40% each by Tyr(4) and Tyr(115), and to the remaining approximately 20% by Tyr(173) and Tyr(175). Y173F and Y175F mutant proteins showed an increase in their fluorescence intensity by approximately 40% and approximately 10%, respectively. These increases appear to be due to multiple effects of increased hydrophobicity, quenching effect of nearby residue Glu(49), and/or energy transfer between Tyrs. Two data for Y173F alpha-subunit of urea-induced unfolding equilibrium monitored by UV and fluorescence were different. This result, together with ANS binding and far UV CD, shows that folding intermediate(s) of Y173F alpha-subunit, contrary to that of wild-type, may contain self-inconsistent properties such as more buried hydrophobicity, highly quenched fluorescence, and different dependencies on urea of UV absorbance, suggesting an ensemble of heterogeneous structures.

Authors+Show Affiliations

Jeong JK
Department of Molecular Biology, College of Natural Sciences, Pusan National University, Jangjeon-dong, Keumjeong-district, 609-735, Busan, Republic of Korea.
Shin HJ
No affiliation info available
Kim JW
No affiliation info available
Lee CH
No affiliation info available
Kim HD
No affiliation info available
Lim WK
No affiliation info available

MeSH

Anilino NaphthalenesulfonatesEnergy TransferEscherichia coliFluorescent DyesHot TemperatureHydrophobic and Hydrophilic InteractionsModels, MolecularMutagenesis, Site-DirectedProtein DenaturationProtein FoldingProtein SubunitsSpectrometry, FluorescenceTryptophan SynthaseTyrosineUrea

Pub Type(s)

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

Language

eng

PubMed ID

12480516

Citation

Jeong, Jae Kap, et al. "Fluorescence and Folding Properties of Tyr Mutant Tryptophan Synthase Alpha-subunits From Escherichia Coli." Biochemical and Biophysical Research Communications, vol. 300, no. 1, 2003, pp. 29-35.
Jeong JK, Shin HJ, Kim JW, et al. Fluorescence and folding properties of Tyr mutant tryptophan synthase alpha-subunits from Escherichia coli. Biochem Biophys Res Commun. 2003;300(1):29-35.
Jeong, J. K., Shin, H. J., Kim, J. W., Lee, C. H., Kim, H. D., & Lim, W. K. (2003). Fluorescence and folding properties of Tyr mutant tryptophan synthase alpha-subunits from Escherichia coli. Biochemical and Biophysical Research Communications, 300(1), 29-35.
Jeong JK, et al. Fluorescence and Folding Properties of Tyr Mutant Tryptophan Synthase Alpha-subunits From Escherichia Coli. Biochem Biophys Res Commun. 2003 Jan 3;300(1):29-35. PubMed PMID: 12480516.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Fluorescence and folding properties of Tyr mutant tryptophan synthase alpha-subunits from Escherichia coli. AU - Jeong,Jae Kap, AU - Shin,Hae Ja, AU - Kim,Jong Won, AU - Lee,Choon Hwan, AU - Kim,Han Do, AU - Lim,Woon Ki, PY - 2002/12/14/pubmed PY - 2003/2/14/medline PY - 2002/12/14/entrez SP - 29 EP - 35 JF - Biochemical and biophysical research communications JO - Biochem Biophys Res Commun VL - 300 IS - 1 N2 - The fluorescence of tyrosine has been used to monitor a folding process of tryptophan synthase alpha-subunit from Escherichia coli, because this protein has 7 tyrosines, but not tryptophan. Here to assess the contribution of each Tyr to fluorescence properties of this protein during folding, mutant proteins in which Tyr was replaced with Phe were analyzed. The result shows that a change of Tyr fluorescence occurring during folding of this protein is contributed to approximately 40% each by Tyr(4) and Tyr(115), and to the remaining approximately 20% by Tyr(173) and Tyr(175). Y173F and Y175F mutant proteins showed an increase in their fluorescence intensity by approximately 40% and approximately 10%, respectively. These increases appear to be due to multiple effects of increased hydrophobicity, quenching effect of nearby residue Glu(49), and/or energy transfer between Tyrs. Two data for Y173F alpha-subunit of urea-induced unfolding equilibrium monitored by UV and fluorescence were different. This result, together with ANS binding and far UV CD, shows that folding intermediate(s) of Y173F alpha-subunit, contrary to that of wild-type, may contain self-inconsistent properties such as more buried hydrophobicity, highly quenched fluorescence, and different dependencies on urea of UV absorbance, suggesting an ensemble of heterogeneous structures. SN - 0006-291X UR - https://www.unboundmedicine.com/medline/citation/12480516/Fluorescence_and_folding_properties_of_Tyr_mutant_tryptophan_synthase_alpha_subunits_from_Escherichia_coli_ DB - PRIME DP - Unbound Medicine ER -