A Versatile, Inquiry-Based Enzyme Lab: The Inhibition of Acetylcholinesterase from Bean Beetles by an Organophosphate Insecticide and Factors that Modulate this Inhibition

 

Hector Fermin, Gurcharan Singh, Rahat Gul, & Fardad Firooznia

Tested Studies in Laboratory Teaching, 2015, Volume 36

Abstract

Here we expand on an enzyme lab that can lend itself to a multi-session investigative approach. We use a colorimetric enzyme assay to look at the inhibitory effect of the organophosphate insecticide malaoxon on the activity of acetylcholinesterase (AChE) extracted from the bean beetle Callosobruchus maculatus. This system can be used to introduce long-term projects on which students can focus in the ensuing lab sessions. Examples include investigating whether different food sources affect sensitivity of AChE to malaoxon, and whether there are differences in sensitivity of AChE extracted from different strains of the beetles to the insecticide.

Keywords:  enzyme assay, bean beetle, acetylcholinesterase

University of Oregon (2014)