Alexa Fluor 594 is a fluorescent molecule commonly used to tag calmodulin, a protein that regulates a variety of cell processes. By measuring fluorescence, scientists can study calmodulin and its interactions with other proteins. However, fluorescence is not the only fate of Alexa Fluor 594. The molecule is also known to transfer energy to coupled amino acids through a mechanism called quenching. The purpose of this experiment was to study the quenching effects of Histidine, Tyrosine, and Methionine on the Alexa Fluor 594. These amino acids’ Stern-Volmer plots suggest static quenching may be occurring. Moreover, the Stern-Volmer plot of Potassium Iodide (KI), a dynamic quencher, suggested that KI quenches the excitation Alexa Fluor 594 in part through a static mechanism. We plan to replicate our experiment and complete statistical testing to determine the significance of our data. Determining if these amino acids quench AlexaFluor594 will help researchers better characterize the calmodulin protein and its interactions
