When working with protein samples , there are critical factors that must be closely monitored to avoid their degradation or dysfunction and guarantee the reliability of the results.
These factors therefore reflect the quality of the proteins and can be basically summarized as:
In this post we bring you some tips to improve the quality of proteins and thus optimize the results of the tests.
1.- OPTIMIZATION OF PROTEIN PURITY AND INTEGRITY
Optimizing the purity and integrity of proteins involves avoiding or minimizing contamination of the sample with impurities, modified proteins or degradation products, among others.
Some of the steps that can be taken to this end are:
- Change the purification protocol by modifying for example the washing and elution conditions or adding additional purification steps such as ion exchange chromatography.
- Modify the conditions of induction of protein expression
- Use a different cloning vector
- Use a different expression system
2.- OPTIMIZATION OF PROTEIN HOMOGENEITY AND SOLUBILITY
To prevent or eliminate the formation of aggregates and increase the solubility of the protein s interest, there are several points that can affect, such as:
- Always perform size exclusion chromatography as the last step in the protein purification process.
- Do not over-concentrate the sample, since the processes applied for this purpose usually induce the aggregation of proteins (Remember this entry about 5 techniques to concentrate proteins ).
- Modify the composition of the buffer in which the protein is located until optimizing the pH, salinity, additives, etc. best suited in each case.
3.- OPTIMIZATION OF THE STABILITY AND STORAGE OF PROTEINS
Regarding the stability and medium or long-term storage of proteins, it is common to think that freezing and cryopreservation is the ideal method. And although this is true in a large part of the cases, it is not always the case due to the intrinsic variability of each individual protein.
That is why it is advisable to study the stability of each protein of interest to identify the optimal storage method in each case, whether it be simple refrigeration, freezing, lyophilization, etc.
You can expand the information in this post on How to store proteins to avoid their degradation .