Parkinson’s disease affects more than 4 million people worldwide. In the United States, Parkinson’s disease occurs in approximately 13 per 100,000 people, and about 60,000 new cases are identified each year. With more people living longer than before, the number of people who can get this disease is expected to increase in the coming decades. Parkinson's disease is highly senile, and this disease has seriously threatened the health of elderly people. This disease leads to a gradual loss of physical motor function, lethargy, inconvenience, and slowness of movement. At the same time, patients will also have different degrees of depression and anxiety symptoms. There is an urgent need for medical treatments that are both effective and affordable for the majority of the aged population. However, the current medication cannot satisfy the demand for most aged population, since it only relieves the symptom and maintains the life quality of the patients to some extent.
During our process of reading massive public literature on the matter, we came across a relatively new target, angiogenin (ANG) protein, a secreted ribonuclease. According to the literatures, angiogenin has been recognized to play important roles in various physiological and pathological processes, especially in neurodegenerative diseases. The loss-of-function mutation of the ANG gene is likely to be an important cause of certain nervous system diseases such as Parkinson’s disease. Therefore, we realized that the delivery of active angiogenin protein could reduce neurodegeneration and could possibly be used as a clinical treatment once we correctly inject the protein.
In our project, we aim to create a recombinant bacteria that can secret functional ANG protein, which could possibly serve as an in vitro method to massive produce ANG for clinical use.
pET-28a-rANG which produces ANG protein is shown in Figure 1.
Figure 1. Schematic map of pET-28a-rANG plasmid and its construction.
We have obtained Freeze-dried powder of the ANG protein produced by our engineered Escherichia coli (Figure 2).
Figure 2. Freeze-dried powder of the ANG protein.
The activity of recombinant ANG protein was determined by the RNA degradation assay. The result indicated that ANG protein possesses ribonuclease activity as we expected.
Figure 3. RNA degradation by ANG.