+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Fluorescence and folding properties of Tyr mutant tryptophan synthase alpha-subunits from Escherichia coli



Fluorescence and folding properties of Tyr mutant tryptophan synthase alpha-subunits from Escherichia coli



Biochemical and Biophysical Research Communications 300(1): 29-35



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.

Please choose payment method:






(PDF emailed within 1 workday: $29.90)

Accession: 046105691

Download citation: RISBibTeXText

PMID: 12480516


Related references

Structure and folding of mutant escherichia coli tryptophan synthase alpha subunits. Journal of Cellular Biochemistry Suppl. (9 Part B): 95, 1985

Enzymatic properties of mutant Escherichia coli tryptophan synthase alpha-subunits. Journal of Biological Chemistry 266(30): 20205-20212, 1991

Enzymatic properties of mutant escherichia coli tryptophan synthase alpha subunits obtained from in vitro mutagenesis of the trp a gene. FASEB Journal 4(7): A1760, 1990

Homodimers of mutant tryptophan synthase alpha-subunits in Escherichia coli. Biochemical and Biophysical Research Communications 289(2): 568-572, 2001

Enzymatic properties of mutant Escherichia coli tryptophan synthase a-subunits. The Journal of Biological Chemistry 266: 205-12, 1991

Unfolding properties of tryptophan-containing alpha-subunits of the Escherichia coli tryptophan synthase. Journal of Biological Chemistry 270(47): 28177-28182, 1995

Thermal stabilities of mutant Escherichia coli tryptophan synthase alpha subunits. Archives of Biochemistry and Biophysics 292(1): 34-41, 1992

Tryptophan-containing alpha-subunits of the Escherichia coli tryptophan synthase. Enzymatic and urea stability properties. Journal of Biological Chemistry 270(30): 17712-5, 1995

Relative activities and stabilities of mutant Escherichia coli tryptophan synthase alpha subunits. Journal of Bacteriology 173(6): 1886-1893, 1991

Substrate interactions with the alpha-subunit of the Escherichia coli tryptophan synthase. A study of the activity of mutant alpha-subunits. Archives of Biochemistry and Biophysics 181(2): 428-437, 1977

Crystallization and X-ray crystallographic studies of wild-type and mutant tryptophan synthase alpha-subunits from Escherichia coli. Molecules and Cells 19(2): 219-222, 2005

Transient non-native interactions in early folding intermediates do not influence the folding kinetics of Escherichia coli tryptophan synthase b2 subunits. European Journal of Biochemistry 240: 5-21, 1996

Transient non-native interactions in early folding intermediates do not influence the folding kinetics of Escherichia coli tryptophan synthase beta 2 subunits. European Journal of Biochemistry 240(3): 615-621, 1996

In vitro mutagenesis and overexpression of the Escherichia coli trpA gene and the partial characterization of the resultant tryptophan synthase mutant alpha-subunits. Journal of Biological Chemistry 261(35): 16604-16615, 1986

Unfolding properties of tryptophan-containing a-subunits of the Escherichia coli tryptophan synthase. The Journal of Biological Chemistry 270: 177-82, 1995