The FLG-derived histidine-rich proteins are converted into urocanic
acid (UCA) and pyrrolidine carboxylic acid (PCA) by proteases.
He described how a nature-inspired urocanic
acid product, called cis-methylthiopropenoic acid conjugate (MTPC), prevents DNA damage and immunosuppressive signaling induced by UVB radiation.
Further processing is triggered by cysteine protease caspase-14,[sup] which produces the hygroscopic degradation products urocanic
acid and pyrrolidone carboxylic acid (known as essential components of the natural moisturizing factors, NMF).
Based on laboratory investigations, the authors first assumed that the megaloblastic hematopoiesis accompanied by urinary excretion of large amounts of urocanic
acid following oral dose of histidine hydrochloride was responsible for aplastic crisis in these patients with HS.
Great differences were observed in the utilization of L-arabinose, urocanic
acid, [alpha]-glycerol-phosphate, glucose-1-phosphate, and glucose-6-phosphate which were positive for 14%, 18%, 50%, 47%, and 33% of the strains, respectively, instead of not being preferred as a sole carbon source.
When filaggrin deficiency is present, trans urocanic
acid (UCA) does not form.
Further detailed studies lead to the identification of the substance from skin extracts of potential hosts which was "urocanic
One such compound is urocanic
acid found on the epidermis layer of human skin and more prevalent when sweating.
Skin: The skin is naturally protected from the sun's radiation by the thickness of the epidermis, melanin, natural antioxidants, DNA repair mechanism, Urocanic
acid and Fas ligand signaling.
A further 8 treatments (humic acid, mannitol, sucrose, root exudates, thiamin, urocanic
acid, cellulose, fulvic acid) showed an increase in the amount of cumulative C[O.sub.2]-C respired compared with the control solution, but this was less than or equivalent to the total amount of substrate applied (30 [micro]g C/g soil; Fig.