Comparative steady-state fluorescence studies of cytosolic rat liver (GTP), Saccharomyces cerevisiae (ATP) and Escherichia coli (ATP) phosphoenolpyruvate carboxykinases
Author
dc.contributor.author
Encinas, M. Victoria
Author
dc.contributor.author
Rojas, M. Cecilia
Author
dc.contributor.author
Goldie, Hughes
Author
dc.contributor.author
Cardemil, Emilio
Admission date
dc.date.accessioned
2018-12-20T14:34:22Z
Available date
dc.date.available
2018-12-20T14:34:22Z
Publication date
dc.date.issued
1993
Cita de ítem
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Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular, Volumen 1162, Issue 1-2, 2018, Pages 195-202
Identifier
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01674838
Identifier
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10.1016/0167-4838(93)90147-J
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/156517
Abstract
dc.description.abstract
Two members of the ATP-dependent class of phosphoenolpyruvate (PEP) carboxykinases (Saccharomyces cerevisiae and Escherichia coli PEP carboxykinase), and one member of the GTP-dependent class (the cytosolic rat liver enzyme) have been comparatively analyzed by taking advantage of their intrinsic fluorescence. The S. cerevisiae and the rat liver enzymes show intrinsic fluorescence with a maximum emission characteristic of moderately buried tryptophan residues, while the E. coli carboxykinase shows somewhat more average exposure for these fluorophores. The fluorescence of the three proteins was similarly quenched by the polar compound acrylamide, but differences were observed for the ionic quencher iodide. For the ATP-dependent enzymes, these last experiments indicate more exposure to the aqueous media of the tryptophan population of the E. coli than of the S. cerevisiae enzyme. The effect of nucleotides on the emission intensities and quenching efficiencies revealed substrate-induced co