Infrared Free Electron Laser or Polarized Ultraviolet Photolysis of Hierarchical and Chiral Components of Interleukin-6, AlanylAlanine and Alanine:

Abstract

Interleukin-6 (IL-6) could be decomposed by irradiation of IR-FEL (Infrared free electron laser). Using circularly polarized and other UV light and IR-FEL light, photolysis of hierarchical components of cast films of IL-6, namely deuterated aqueous solutions of enantiomers of dipeptide (L-alanyl-L-alanine (Ala-ala) or D-alanyl-D-alanine) and enantiomers of amino acid (L-alanine (Ala) or D-alanine) was investigated whether specific bonds can be broken by absorption of light (not due to heat). In addition, IR-FEL irradiation to powder as well as crystal structure determination for L-Ala and D-Ala at 173 and 293 K were also carried out to confirm reproducibility in the solid state about long-lasting controversy about Salam’ hypothesis associated with chirality exhibiting structural phase transition at different temperature. Subunits of IL-6 (dipeptide and amino acid) could not be decomposed by polarized IR-FEL nor UV (ultraviolet) light regardless of their chirality. All experimental methods tested in this study failed to prove Salam's hypothesis, positively. Consequently, secondary structure of IL-6 was found to be easier to be damaged by IR-FEL than covalent bonds. HIGHLIGHTS Interleukin 6 (IL-6) was decomposed by irradiation of IR-FEL (Infrared free electron laser). Parts of IL-6 (dipeptide and amino acid) was not decomposed by polarized IR-FEL nor UV (ultraviolet) light regardless of their chirality. Secondary structure of IL-6 was easier to be damaged by IR-FEL than covalent bonds.