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Updated: Oct 2, 2026

Direct Detection of the Acetate-forming Activity of the Enzyme Acetate Kinase
Published on: December 19, 2011
Reagent-less detection of a competitive inhibitor of immobilized acetylcholinesterase
Brandy J White1, J Andrew Legako, H James Harmon
1Department of Physics, Oklahoma State University, Stillwater, OK 74078, USA.
Abstract:
The interaction of monosulfonate tetraphenyl porphine (TPPS(1)) with immobilized acetylcholinesterase (AChE) yields a characteristic absorbance peak at 446 nm. Addition of acetylcholine iodide or the competitive inhibitor tetracaine to the immobilized TPPS(1)-AChE complex results in a decrease in absorbance intensity at 446 nm due to displacement of the porphyrin from the active site. The loss in intensity at 446 nm is linearly dependent on tetracaine concentration at levels below 100 ppb. Tetracaine concentrations as low as 300 ppt have been detected.
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