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aCella™ - AChE 
Bioluminescence Non Radioactive Assay for monitoring Acetylcholinesterase activity * Patent Pending
Key Benefits:
  • Safe - Non Radioactive Enzyme activity assay.
  • Versatile: Nerve Gas, Pesticide Monitoring, drug screening Applications
  • Homogenous - One-step, no wash assay.
  • FAST - Results in 30 secs - 5 minutes.
  • Highly Sensitive
  • HTS - Adaptable for High Throughput format
  • Applications - Standard luminometer readout
Introduction to aCella - AChE

Acetylcholinesterase (AChE) is one of the most important enzymes involved in nerve transmission. The enzyme is bound to cellular membranes of excitable tissue (synaptic junction, endoplasmic reticulum, etc)1-3. Acute toxicity to humans and animals through inhibition of AChE by both nerve gases and an important class of pesticides has long been a field of intensive scientific investigation 4,5. AChE inhibitors have also been used clinically as Alzheimer’s treatments (e.g., tacrine (tetrahydroaminoacridine)) (6) and are the subject of increasing interest in various disease processes and treatment strategies 7,8. However, both environmental detection of AChE inhibitors and development of modulators of AChE enzymatic activity as drugs have been hampered by the difficulty and complexity of the current assay methods.
Assay Principle:

We have developed a highly sensitive, very rapid, extremely simple assay for AChE activity, using the natural substrate, acetylcholine. As shown in Figure 1, a series of coupled enzyme reactions quickly translates the presence of active AChE into a change in the luminance of the reaction. First (reaction I), acetylcholine is hydrolyzed by the AChE to yield acetate and choline. The acetate and choline then enter a coupled enzyme reaction (reaction II) that results in consumption of ATP, and finally the ATP concentration is measured by the well-established luciferase method (reaction III). These reactions can occur simultaneously, and the result is generally obtained in five minutes or less. Inhibitors of AChE are readily detected by an increase in luminance due to reduced consumption of ATP.

The following reaction illustrates the sequence of events if AChE inhibitors are present:
Reaction I: AChE + Inhibitor No Acetate and Choline
Reaction II: Coupled Enzyme Reaction + ATPReaction does not proceed
Reaction III: ATP (remaining) + Luciferase/LuciferinLIGHT
aCella™-AChE


Figure A. Tacrine (a mixed-mode inhibitor of AChE) was serially diluted in DI water. Next 10mL of the diluted Tacrine (x axis labeling represents mM final concentration of Tacrine) was added to a white opaque 96-well microplate along with 50 mL of component A (AChE enzyme). The samples were incubated for 5 minutes after which 50mL of component B was added to all the wells. Data were collected using a luminometer. Data shown represents T=2 minutes after the addition of component B.

aCella™-AChE


Figure B. Malathion, a common pesticide, was first diluted in DMSO and subsequently serially diluted in Di water. 10μL of the diluted Malathion (x axis represents μM final concentration of Malathion) was added to a white opaque 96-well microplate followed by 50 μL of component A (AChE enzyme). The mixture was incubated for 15 minutes, after which 50 μL of component B was added to all the wells. Data were collected using a luminometer. Data shown is at T= 5 minutes. Data shown represents T=2.5 minutes after the addition of component B.

 

Product Catalog # Size*
Non Radioactive Acetylcholinesterase Monitoring Assay CLACHE 100-2 100
Non Radioactive Acetylcholinesterase Monitoring Assay CLACHE 100-3 500
Non Radioactive Acetylcholinesterase Monitoring Assay CLACHE 100-4 1000