X-ray absorption spectroscopy of selenium-containing amino acids.
The selenium K-edge X-ray absorption spectra of selenomethionine, selenocysteine, selenocystine, and sulfo-selenocystine in solution are compared with the corresponding sulfur K-edge spectra of the sulfur analogues of these compounds. The selenium and sulfur spectra follow similar trends, although the latter are significantly sharper owing to the longer core hole lifetime at the lower energies where sulfur absorbs. The spectra of the selenium compounds are sufficiently distinct that it is reasonable to expect that curve fitting will allow the speciation of the forms of selenium in complex biological samples.
Pickering
I J
IJ
Stanford Synchrotron Radiation Laboratory, Stanford Linear Accelerator Center, CA 94309, USA. pickering@ssrl.slac.stanford.edu
George
G N
GN
Van Fleet-Stalder
V
V
Chasteen
T G
TG
Prince
R C
RC
D000596:Amino Acids / Q000737:chemistry*; D012643:Selenium / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods*; D014965:X-Rays
D000596:Amino Acids; D012643:Selenium