Abstract
Human catechol-O-methyltransferase (COMT; EC 2.1.1.6) catalyzes the transfer of the methyl group to a variety of endogenous and exogenous catechol substrates using S-adenosyl-L-methionine as the methyl donor. This enzymatic O-methylation plays an important role in the inactivation of biologically active and toxic catechols. A number of studies in recent years have sought to characterize the polymorphism of human COMTs and also to determine the catalytic activity of polymorphic enzymes. We report here the identification of a new haplotype of the human COMT gene with triplet point mutations, which encodes the D51G/S60F/K162R mutant of the soluble COMT and the D101G/S110F/K212R mutant of the membrane-bound COMT. Kinetic analysis showed that these new COMT variants had essentially the same kinetic characteristics and catalytic activity as the wild-type COMTs for the O-methylation of 2-hydroxyestradiol and 4-hydroxyestradiol in vitro, but they have a significantly reduced thermostability at 37 degrees C.
Sign-in/Register to access full text options 
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 callDisclaimer: 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.
