Chemists at MIT have developed a new optical sensor that tracks Zinc, an essential nutrient residing in tissue cells of the human body.
As only a trace element, Zinc is fundamental for the normal functioning of a majority of biological systems (for example, when tightly bound to protein structures in cellular tissue; or in its free form during which it becomes crucial for the functioning of organs such as the brain, pancreas, and glandular tissue).
To help decipher exactly how this element functions in the cell, MIT researchers have developed a new optical sensor that can track zinc. Upon binding to the sensor, zinc initiates a cascade of reactions that cause the sensor to fluoresce, which provides a better indication of exactly where the element is located within the cell.
One particular condition targeted for the use of this sensor is prostate cancer. Research has found that prostate cancerous cells tend to have much lower levels of zinc compared to healthy cells placing much attention on the process of zinc trafficking and how this may be modified in cancerous tissue.
Image credits: Photos.com.
Looking for Zinc
The Lippard Lab first introduced a molecule 10 years ago that has been adapted from the dye fluorescein which has now become important for the development of the zinc sensor (Zinpyr1) - a target that lights up when it makes contact with zinc.
To avoid trapping the zinc sensor in acidic vesicles inside the cell (making the cell inactive), the lab used a zinc-reactive protecting group, which modified the properties of the zinc sensor thereby creating a sensor that becomes easy to identify by the trace element.
The positive charge and hydrophobic properties of a ZP1 tag locates the zinc sensor to the mitochondria of the cell. Once attached to the cell, the sensor allows the researchers to visualise the traces of zinc within the mitochondria.
With zinc playing an important role as an antioxidant and the up-keep of DNA, there’s great emphasis on using this sensor to help understand how the dysregulation of zinc trafficking can then change genomic stability.
The team aim to progress this research by using this fabricated sensor to unlock specific biochemical pathways that are important for helping bind zinc to proteins within the cell for regular cellular function. There will also be much more attention on how structural changes in cellular proteins affect the abundance of free and bound zinc within the cell.
Sensor technology for the medical industry is helping speed up diagnosis and treatment protocols for many ailments. With breast cancer and prostate cancer being commonly diagnosed worldwide, using a sensor to help track how zinc is behaving in cancerous tissue will bring research one step closer to defining how these conditions develops.
MIT News – New Sensors tracks Zinc in cells
Alam S et al. Cellular Mechanisms of Zinc Dysregulation: A Perspective on Zinc Homeostasis as an Etiological Factor in the Development and Progression of Breast Cancer. Nutrients 2012, 4(8), 875-903.