Abstract

Cysteine dioxygenase is an iron (Fe(2+))-dependent thiol dioxygenase that uses molecular oxygen to oxidize the sulfhydryl group of cysteine to generate 3-sulfinoalanine (commonly called cysteinesulfinic acid). Cysteine dioxygenase activity is routinely assayed by measuring cysteinesulfinate formation from substrate L-cysteine at pH 6.1 in the presence of ferrous ions to saturate the enzyme with metal cofactor, a copper chelator to diminish substrate oxidation, and hydroxylamine to inhibit pyridoxal 5'-phosphate-dependent degradation of product. The amount of cysteine dioxygenase may be measured by immunoblotting. Upon SDS-PAGE, cysteine dioxygenase can be separated into two major bands, with the upper band representing the 23-kDa protein and the lower band representing the mature enzyme that has undergone formation of an internal thioether cross link in the active site. Formation of this cross link is dependent upon the catalytic turnover of substrate and produces an enzyme with a higher catalytic efficiency and catalytic half-life.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.