We present a simple enzyme assay using the robust horseradish peroxidase and the indicator guaiacol which, when oxidized to form tetraguaiacol, can be detected and quantified using a visible spectrophotometer at 470nm. This assay uses buffers (NaPO4), substrates (H2O2) and equipment already widely used and available in most first-year laboratories and is a cost-effective addition to current experiments. In addition to determining and comparing specific activity under a variety of traditional variables (pH, temperature) participants will use L-cysteine, reported in the literature to be a non-competitive inhibitor of peroxidase. L-cysteine demonstrates a unique inhibition pattern in our assay losing its inhibitory characteristics in a concentration and time dependent manner. This gives the instructor a range of options to demonstrate enzyme inhibition as well as an opportunity for investigations and self-directed experimentation by the students with a more challenging result to consider and analyze.
We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.Ok