Protein kinases are enzymes that take phosphate groups from adenosine triphosphate (ATP) molecules, the energy in your body, and add them to other specific molecules inside the cell. This transfer of the phosphate group can activate or deactivate the target molecule, thus regulating cellular activities such as growth, replication, and respiration. The kinases studied here are hemopoietic cell kinases (Hck kinases) under the class of Scr kinases. Hck kinases are present in bone marrow and are often associated with myeloid leukemias and myeloproliferative disorders. Studies have shown that in the active conformation, the Hck kinase detaches two of its domains, SH2 and SH3, resulting in a more extended conformation. Using a Waters Synapt G2 HDMS, ion mobility mass spectrometry (IM-MS) techniques were used to probe the size of inactive and active Hck kinases by measuring drift times of their gas-phase ions traveling through a neutral background gas under the presence of a weak electric field. Drift times were then converted into collision cross section (CCS) values, which depend on the size and shape of the ion of interest. Eight different small molecules (< 500 Da) were used to inhibit Hck kinases, and changes in conformation were investigated using IM-MS. Preliminary data shows no significant changes in global conformation or size, conflicting with the previous studies. To investigate more subtle changes in conformation, collision induced unfolding (CIU) methods are used. By selecting an ion of interest using a quadrupole mass filter, protein unfolding is monitored using ion mobility as a function of ion activation prior to ion mobility analysis. This process allows an investigation of the subtle conformational changes in the Hck kinase upon the binding of small inhibitor molecules.

Electrospray ionization (ESI) is a powerful tool for transferring intact protein complexes from solution to the gas phase. ESI creates multiply charged ions with a net positive (cation) or negative (anion) charge. Although the structures of gas-phase protein cations have been investigated extensively, relatively little research addressing the structures of negatively charged protein ions exists in the literature. In my research, I use ion mobility (IM) to measure drift times, or the time an ion takes to traverse a gas-filled drift tube in the presence of a weak electric field. The drift times for ions depend on their charge and collision cross section (CCS), which to a first approximation, is the orientationally averaged projected cross section of its structure. Therefore, the drift times of ions depend on their structure. Preliminary CCS values that I have measured for protein complex anions are slightly smaller than values in the literature for the analogous protein complex cations, which suggests that the anions are more compact than the cations. One challenge in interpreting those results is the anions had a lower absolute number of charges than the analogous cations, so the results may not be directly comparable. The focus of my research is to make more direct comparisons between the structures of protein complex cations and anions. To this end, I am developing methods to reduce the number of charges on protein complex cations to values equal to those observed previously for the anions. CCS values determined for these charge-reduced cations will be directly comparable to those measured for the anions, and should reveal any structural differences between protein complex cations and anions. These results will also be useful for calibrating other IM experiments and determining how best to use IM to characterize the native structures of protein complexes.

My poster will be about the beginnings and politics behind the Somali Piracy phenomena. The stories being told by the media and the stories being lived out in Somalia are very different. Over the past 25 years, specifically during the early 90's during times of war, many wealthy western nations took to Somalia to dump their toxic waste. With no permission or ok from the country's government. This took away from fishing as a livelyhood and a business to the country. Fishing was a top moneymaker in Somalias economy and within years it was almost wiped out. No one heard of Somalia's cries for help of there shoreline. For the defects of their babies born with defects. Some turned to piracy which we see playing out today. This presentation will document data and facts surrounding the phenomena of Somali Pirates.