Circular dichroism and Fourier transform infrared spectroscopic studies on the secondary structure of Saccharomyces cerevisiae and Escherichia coli phospho enolpyruvate carboxykinases.
The secondary structure of Saccharomyces cerevisiae and Escherichia coli phospho enolpyruvate (PEP) carboxykinases was quantitatively examined using circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopies. From CD analyses, values of 24% alpha-helix and 38% beta-sheet were obtained for the E. coli enzyme, while the corresponding values for the S. cerevisiae PEP carboxykinase were 20% and 36%. Analysis of the amide I' infrared band indicated 20% alpha-helix and 36% beta-sheet for the S. cerevisiae enzyme, while for the E. coli protein values of 40% beta-sheet and between 9 and 36% alpha-helix could be inferred. It is concluded that the bacterial enzyme has more secondary structure elements than the yeast protein. No alteration of the CD or FTIR spectra was detected upon substrate or metal ion binding to any enzyme.
Encinas
M V
MV
Departamento de Ciencias Químicas, Facultad de Química y Biología, Universidad de Santiago de Chile.
Olsen
L R
LR
Díaz
J F
JF
Andreu
J M
JM
Goldie
H
H
Cardemil
E
E
D002942:Circular Dichroism; D004926:Escherichia coli / Q000201:enzymology*; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000737:chemistry* / Q000302:isolation & purification; D017433:Protein Structure, Secondary; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D017550:Spectroscopy, Fourier Transform Infrared
D010729:Phosphoenolpyruvate Carboxykinase (GTP)