Achievement

Another achievement was the successful development and characterization of a molecular switch created through genetic engineering, combining the proteins of cAMP receptor protein (CRP) and the bioluminescent protein aequorin (Aeq). Aeq is a bioluminescent protein which in the presence of coelenterazine and calcium emits a flash of light at 469 nm. Aeq has been genetically split in two halves and CRP has been inserted in between the two halves. In the absence of cAMP the two halves of Aeq are in close enough proximity to reunite and form the active Aeq complex. Upon binding of cAMP by CRP the halves of Aeq are pulled too far apart to form the active complex, thus decreasing the intensity of the bioluminescent signal seen. These investigators showed that the switch responds selectively to cAMP in a linear fashion over several orders of magnitude. In addition the switch has been shown to be effective in monitoring increases and also decreases in cAMP levels of intact cells.