One semester to be graduate… a research to be concluded

 

During this semester, I mainly want to establish whether or not the XRD results that I have gotten are reliable. Because of this, I am polymerizing again all the PEG hydrogels and then I will crystallize lysozyme to see if the XRD results are the same. With this I will be able to conclude if the hydrogels are better than agarose to control counter-diffusion of the precipitant agent and, as a consequence, if hydrogels can optimize the crystallization process. A second goal for the semester is to work with proteins that are not as easy to crystallize as lysozyme to determine if we can get good-quality crystals of proteins different than lysozyme. Consequently, we have chosen to crystallize myoglobin and hemoglobin and then perform XRD to the obtained crystals and determine if the ‘optimized’ crystallization process provides good hemoglobin and myoglobin crystals.

As you may see, this semester I just want to repeat the experimentation that I have been doing and determine if the crystallization technique was optimized. Preliminary results show that we can be able to get good crystals with hydrogels but we do not have reliable conclusions yet. As soon as we get the conclusions that we need, I will move forward to use myoglobin and hemoglobin.

Since the experimentation is basically the same, probably I will not be working with new techniques. Nevertheless, I will continue using X-ray Diffraction which has been one of the most valuable techniques that I have learned. I used it on December to get quantitative, preliminary results. The technique consists of emitting x-rays across a protein crystal that will be diffracted by the electron contained in the protein’s atoms. The x-rays are then detected and a software generates a diffraction pattern that is then analyzed to determine how well organized are the atoms in the crystalline structure. If the atoms are well organized, the crystal is said to have good quality and this can help in generating an electron density map. That map then allows predicting the protein morphology which has excellent applications in the biomedical sciences such as: drug development, study of a protein behavior in a biological environment, etc.