Novel Structural Details of Opioid Receptor Identified

Rachel Kogan ‘19

Figure 1. Researchers have identified structural details of opioid receptors that may be targeted in non-addictive pain medications.

Opioid addiction has been on the rise for decades across the nation. Often times, these addictions are spurred by an initial pain medication prescription administered by health professionals. As a result, the health care field finds itself at a crossroads between administering the medication to aid individuals in living a pain-free life and potentially propagating addictive behaviors. Most pain medications affect the mu opioid receptor, which elucidates not only analgesia but also euphoria, the sensation most commonly sought after in addiction.

Recently, the field’s focus shifted to analyzing a separate type of opioid receptor, known as the kappa receptor. Unlike the mu receptor, the kappa receptor, when activated, does not produce euphoria. This inspired a team of researchers led by Bryan Roth of the Department of Pharmacology at the University of North Carolina at Chapel Hill School of Medicine to analyze the protein’s structure. The scientists were the first to crystallize the receptor and subsequently determine its structure in both the active and inactive state. These results may provide insight into the receptor’s intricate function.

When targeted by current medications, the kappa receptor produces negative side effects such frequent urination, hallucinations, and dysphoria, or severe unhappiness. Having a greater understanding of the receptor’s structure may allow scientists to develop medication that targets its analgesic aspects without perpetuating the negative side effects. As a result, it may be possible that a novel group of non-addictive medication will soon emerge to combat the current opioid epidemic.



  1. B. Roth, et. al., Structure of the Nanobody-Stabilized Active State of the Kappa Opioid Receptor. Cell 172 55-67 (2018). doi:  
  2. Image retrieved from:

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