You are here

Home » Blogs » ziweiwang's blog

result conclusion and the impact of the study

Submitted by ziweiwang on Thu, 11/07/2019 - 23:08

The second experiment established that in the N15S, one glycosylation site is missing, which caused a change of molecular weight, allowing it to have a lower molecular weight than normal. After PNGase F treatment, however, the protein appears more similar to the wild type indicating that it is more like the wildtype compared to when it is not treated. In the P23H, the mutation that the group is interested in, there was also a lower molecular weight, which indicates that there is degradation. Compared to the control, both of the dimers were had a heavier molecular weight compared to that of the wild type which indicates that aggregation is more severe in the mutants, with the P23H being more severe compared to N15S(figure 3)

 

In the 3rd experiment, the total fluorescence was lower than the wild type in both of the mutants. The researchers hypothesized that this may be due to the aggregation of the mutant proteins. There was a reduction in the stability in N15S, compared to WT, and P23H was much less stable compared to both. However, because there was a total decrease of fluorescence signal, which indicates that the properties of that are expressed in this experiment causes some of the mechanism of pathogenesis of the mutants. 

 

In the fourth experiment, the experiment indicated that in N15S, there was a decrease in alpha helix, an increase in beta-sheet, random coils and turns compared to the wild type. In the P23H, there were even more differences compared to that of wild type with an increase in random coil and decrease in alpha-helix, beta-sheet and turns. This indicates that when the P23H mutation happens, there is a larger structural change compared to the N15S mutation. (figure 4, table1)

 

In the fifth experiment, the rescue experiment was conducted. The proteins were denatured, in the presence and absence of chlorin e6.  The proteins were then put through circular dichroism spectroscopy. In the resulting graph, the % helix content was lower in P23H with chlorin e6, but not in N15S. This indicates that the compound restored some of the stability to the protein with a mutation of P23H.  This implies that compound chlorin e6 may be a viable treatment for patients with a mutation of P23H but not with N15S.

The experiment provided the answer that when N15S mutation and P23H mutation was compared, in general, the P23H mutation was less stable, and had a higher aggregation compared to N15S. However, despite the more serious effect of the mutation, P23H was also able to be resued by a compound choline e6, indicating that while the symptom of those with the mutation of P23H is more severe, there is also a compound that is likely to be able to rescue the mutation and restore the stability of the protein, and preventing it from aggregating.
 
The paper impacts the disease by indicating why the mutation of P23H has a more impact compared to patients with a mutation in S15N. This study also indicates which secondary structures of the protein may be the reason for the illness, and a possible compound can be tested in animal studies, for their ability to stabilize the alpha helix of the P23H protein mutations.

Post: