In this latest instalment of our column from the Mass Spectrometry Research Center at Vanderbilt University, Danielle Gutierrez discusses techniques for membrane protein preparation for IMS.
Membrane proteins have a critical role in cell viability and cell-cell interaction. They maintain ion levels, preserve structure among cells, transport essential nutrients and participate in signaling cascades. Membrane proteins are both enticing drug targets and provide a means of drug resistance. Yet, they represent a difficult class of molecules to investigate. Traditional analytical techniques and protocols for mass spectrometry analysis generally underrepresent membrane proteins. Typical lysis buffers solubilize hydrophilic compounds, leaving the more hydrophobic compounds as a precipitated pellet. Even protocols that target membrane proteins can be encumbered with difficulties and often require additional steps. Solubilization of the pellet in a buffer compatible with downstream steps, such as digestion, separation on an LC column and detection, can be challenging.