Abstract

Opioids are simultaneously an essential medicine and a leading cause of death. Metabolic engineering and novel opioids offer solutions to insecure supply chains and harmful side effects but are limited by cost and time required for high throughput screening. We have developed a yeast-based opioid biosensor to accelerate opioid research. Utilizing Homo sapiens µ-opioid receptor as a detector, our biosensor provides a simulacrum of in vivo opioid response while maintaining ease of implementation of a yeast chassis. Functional µ-opioid receptor expression required the introduction of cholesterol biosynthesis as well as pH adjustment. We also identified codon usage as a parameter affecting Homo sapiens melatonin receptor1a function and the properties of the µ-opioid receptor binding. Under optimized conditions our opioid biosensor displayed 157-fold increase in fluorescence after opioid exposure and had µM affinity for opioid peptides and mM affinity for morphine. This opioid biosensor can aid high throughput screening and provides clues for future functional expression of other difficult G-protein coupled receptors.