Demethylation of Methionine and Keratin Damage in Human Hair
February 2018
in “
Amino acids
”
TLDR Copper and iron cause keratin damage in hair by converting methionine to homocysteine.
The study examined the mechanism of homocysteine (Hcy) accumulation and keratin damage in human hair. It was found that Hcy-keratin levels increased 5–10-fold from the base to the tip of the hair, leading to a complete loss of keratin solubility in sodium dodecyl sulfate. This increase in Hcy-keratin was accompanied by a decrease in methionine-keratin and was correlated with hair copper and iron levels. In vitro experiments confirmed that Hcy generation from methionine depended on copper or iron, suggesting that copper/iron-catalyzed demethylation of methionine residues contributes to keratin damage in human hair.