Abstract
S-Adenosyl-L-homocysteine hydrolase (SAHH) catalyzes the reversible conversion of S-adenosyl-L-homocysteine (SAH) to adenosine (ADO) and L-homocysteine, promoting methyltransferase activity by relief of SAH inhibition. SAH catabolism is linked to S-adenosylmethionine metabolism, and the development of SAHH inhibitors is of interest for new therapeutics with anticancer or cholesterol-lowering effects. We have developed a continuous enzymatic assay for adenosine that facilitates high-throughput analysis of SAHH. This luciferase-based assay is 4000-fold more sensitive than former detection methods and is well suited for continuous monitoring of ADO formation in a 96-well-plate format. The high-affinity adenosine kinase from Anopheles gambiae efficiently converts adenosine to adenosine monophosphate (AMP) in the presence of guanosine triphosphate. AMP is converted to adenosine triphosphate and coupled to firefly luciferase. With this procedure, kinetic parameters (K(m), k(cat)) for SAHH were obtained, in good agreement with literature values. Assay characteristics include sustained light output combined with ultrasensitive detection (10(-7) unit of SAHH). The assay is documented with the characterization of slow-onset inhibition for inhibitors of the hydrolase. Application of this assay may facilitate the development of SAHH inhibitors and provide an ultrasensitive detection for the formation of adenosine from other biological reactions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
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.