Application of XANES profiles to X-ray spectromicroscopy for biomedical specimens: Part I. Discrimination of macromolecules with sulfur atoms

J Xray Sci Technol. 2011;19(2):249-60. doi: 10.3233/XST-2011-0290.

Abstract

XANES spectra of biomacromolecules such as histone, hemoglobin or bovine serum albumin (BSA) were measured in transmission at the S-K absorption edge for comparison with those of sulfur containing low-molecular weight biomolecules with special reference to the dependence on the chemical environment of sulfur. The spectra of dry histone and hemoglobin exhibited a prominent peak at the same energy as that of cysteine and glutathione (GSH), while the BSA spectrum showed an additional peak at a lower energy, which coincided with that of cystine and glutathione disulfide (GSSG). XANES peaks were found at the same energy even in a mammalian cell dry pellet. Spectra in the hydrated state exhibited similar profiles except for a very slight shift of resonance peaks to the lower energy. These results indicate that XANES profiles could be applicable to the mapping of S-C and S-S bonds in dry/hydrated biological systems using a spectromicroscopic technique. In addition, mass absorption coefficients of GSH and GSSG were determined.

MeSH terms

  • Alanine / analogs & derivatives
  • Alanine / chemistry
  • Animals
  • Cattle
  • Cysteine / analogs & derivatives
  • Cysteine / chemistry
  • Cystine / chemistry
  • Glutathione / chemistry
  • Hemoglobins / chemistry
  • Histones / chemistry
  • Macromolecular Substances / chemistry*
  • Methionine / chemistry
  • Molecular Conformation
  • Serum Albumin, Bovine / chemistry
  • Spectrometry, X-Ray Emission*
  • Sulfides / chemistry
  • Sulfur Compounds / chemistry*

Substances

  • Hemoglobins
  • Histones
  • Macromolecular Substances
  • Sulfides
  • Sulfur Compounds
  • Serum Albumin, Bovine
  • Cystine
  • Methionine
  • Glutathione
  • lanthionine
  • Cysteine
  • Alanine