1.2- Dioxetanes 3-galactosidase

Chemiluminescence and bioluminescence are also used in immunoassays to detect conventional enzyme labels (eg, alkaline phosphatase, P-galactosidase, glucose oxidase, glucose 6-phosphate dehydrogenase, horseradish peroxidase, microperoxidase, xanthine oxidase). The enhanced chemiluminescence assay for horseradish peroxidase (luminol-peroxide-4-iodophenol detection reagent) and various chemiluminescence adamantyl 1,2-dioxetane aryl phosphate substrates, eg, (11) and (15) for alkaline phosphatase labels are in routine use in immunoassay analyzers and in Western blotting kits (261—266). 

Another chemiluminescent enzyme system is based on the use of stabilized dioxetane substrates. Dio-xetanes are intermediates in many chemiluminescent reactions. It s possible to synthesize stabilized dio-xetanes (phosphatase and p-galactose moieties) that do not spontaneously react. When exposed to the right enzyme (alkaline phosphatase and p-galactosidase, respectively) the dioxetane will be destabilized and spontaneously undergo a chemiluminescence reaction. " ... 

The 1,2-dioxetanes have mainly been used to develop substrates for the determination of enzymes, the more significant examples being (3-(2 -spiroada-mantane)-4-methoxy-4-(3"-phosphoryloxy) phenyl-1,2-dioxetane sodium salt (AMPPD), a substrate for alkaline phosphatase, and its galactopyranosyl derivative, (3-(2 -spiroadamantane)-4-methoxy-4-(3"-p-D-galactopyranosyloxyphcnyl )-1,2-dioxetane sodium salt (AMPGD), a substrate for p-D-galactosidase. 

Although they have not been used as labels in immunoassays, dioxetane substrates for p-galactosidase have been synthesized and characterized (B18, B23, S9). Current data are sparse, but it would appear that the enzyme is less detectable... 

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