Use of RET to Measure Macromolecular Associations

Energy transfer is widely useful in biochemistry even apart from its application for the measurement of distances. This is because energy transfer occurs independently of the linker joining the donor and acceptor and depends only on the D-A distance. Hence, any process bringing the donor and acceptor into close proximity will result in eneigy transfer. This includes biochemical association reactions, as will be illustrated below for protein subunits and DMA oligomers. 

Dissociation of the Catalytic and Regulatory Subunits of a Protein Idnase 

Cyclic 3, 5 -adraoane inono rfiosphate (cAMP) is an important secemd messrager in cellular (nusducUon pathways, and it is tfius in xxtant to devdop c cal means K detect cAMP. Nucleotides are weakly fluorescent or non-fluorescrat, so that it is not practical to use the intrinsic emission of cAMP. One method to detect cAMP is based on Che effect of cAMP on die cAMP-dqieodent prol kinase. The basic idea is to label the proton subunits widi donors and accept s. The vesaice of cAMP altera the extent of RET, which can be monitored by the donor or accq tor emission. 

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