A Sensitive Assay for the Enzyme Activity in Hair Follicles and Epidermis That Catalyzes the Peptidyl-Arginine-Citrulline Post-Translational Modification
April 2015
in “
Current problems in dermatology
”
TLDR A more sensitive assay was developed to detect enzyme activity converting arginine to citrulline in hair follicles.
The document described an enzymatic activity in hair follicles that converted arginine to citrulline, with trichohyalin identified as the protein precursor substrate in the inner root sheath and medulla. The study highlighted challenges in enriching the enzyme due to the lack of sensitivity and reproducibility in the original colorimetric enzyme assay. A more sensitive assay using radioactively-labelled synthetic substrates was developed, allowing detection of citrulline formation at lower levels. The enzyme required Ca2+ for activity, had a Km of 18 mM for the substrate, and was stable under certain conditions. The study aimed to improve the assay further and investigate the enzyme's properties in guinea pig hair follicles.
