Researchers obtain clearest mitochondrial protein images under physiological conditions

NANJING -- A joint research team from China and the United States has developed a novel method to capture the clearest images of mitochondrial proteins in an environment closest to their native state.

Mitochondria are essential for cells to convert energy from organic matter into a usable form. Proteins contained in mitochondria play an important role in main functions such as aerobic respiration, maintaining mitochondrial structure and regulating metabolism.

Mitochondrial protein images are beneficial for researchers in understanding cellular health. Mitochondria are often used as drug targets. Therefore, understanding drug interactions with them aids in the selection of drugs with therapeutic value, ultimately accelerating the drug discovery process.

Previous scientific studies purified proteins from mitochondria before analysis in a way that could potentially damage protein activity. The joint research team led by Zhu Jiapeng, professor of Nanjing University of Chinese Medicine, and Zhang Kai, professor of Yale University, has come up with a new solution.

"The in vitro purification method allows us to 'take pictures' for the mitochondrial proteins, but these images may differ from their real state. It is like a group of children playing on the playground. If I call on one of the children to take a photo, they would likely act very prim. However, that is not what the child really looks like while playing," said Zhu.

The breakthrough of the study lies in the ability to take images of intact mitochondria in a cellular environment, "like taking snapshots of children playing," Zhu explained.

Their research team has successfully achieved high-resolution imaging of mitochondria of cardiac origin at the level of intact organelles, with a resolution of up to 0.18 nanometers, "allowing observation of every atom in the protein," Zhu added.

Their research can enable further investigation of the impacts of diverse mitochondrial diseases and pharmacological treatments by determining reactive protein structures under physiological conditions within mitochondria. The study was published online on Thursday (Beijing Time) in the journal Nature.