UV B-irradiation enhances the racemization and isomerizaiton of aspartyl residues and production of Nε-carboxymethyl lysine (CML) in keratin of skin

J Chromatogr B Analyt Technol Biomed Life Sci. 2011 Nov 1;879(29):3303-9. doi: 10.1016/j.jchromb.2011.05.010. Epub 2011 May 17.


UV-B irradiation is one of the risk factors in age-related diseases. We have reported that biologically uncommon D-β-Asp residues accumulate in proteins from sun-exposed elderly human skin. A previous study also reported that carboxymethyl lysine (CML; one of the advanced glycation end products (AGEs)) which is produced by the oxidation of glucose and peroxidation of lipid, also increases upon UV B irradiation. The formation of D-β-Asp and CML were reported as the alteration of proteins in UV B irradiated skin, independently. In this study, in order to clarify the relationship between the formation of D-β-Asp and CML, immunohistochemical analysis using anti-D-β-Asp containing peptide antibodies and anti-CML antibodies was performed in UV B irradiated mice. Immunohistochemical analyses clearly indicated that an anti-D-β-Asp containing peptide antibody and anti-CML antibody reacted at a common area in UV B irradiated skin. Western blot analyses of the proteins isolated from UV B irradiated skin demonstrated that proteins of 50-70 kDa were immunoreactive towards antibodies for both D-β-Asp containing peptide and CML. These proteins were identified by proteomic analysis as members of the keratin families including keratin-1, keratin-6B, keratin-10, and keratin-14.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Animals
  • Antibodies / chemistry
  • Blotting, Western
  • D-Aspartic Acid / analysis
  • D-Aspartic Acid / chemistry
  • D-Aspartic Acid / radiation effects*
  • Glycation End Products, Advanced / metabolism
  • Glycation End Products, Advanced / radiation effects
  • Humans
  • Immunohistochemistry
  • Keratins / chemistry
  • Keratins / metabolism
  • Keratins / radiation effects*
  • Lysine / analogs & derivatives*
  • Lysine / metabolism
  • Lysine / radiation effects
  • Mice
  • Proteomics
  • Skin / chemistry
  • Skin / metabolism
  • Skin / radiation effects*
  • Stereoisomerism
  • Ultraviolet Rays*


  • Antibodies
  • Glycation End Products, Advanced
  • D-Aspartic Acid
  • Keratins
  • N(6)-carboxymethyllysine
  • Lysine