In this week’s Under the covers (Nature revealed) blog, Nature’s Art Director Kelly Krause discusses the inspiration behind this week’s front cover choice.
Many of the high-resolution membrane protein structures published recently are notable for the presence of lipids closely associated with the protein, prompting the question, how are these lipids influencing membrane complex structure?
Carol Robinson and colleagues have developed a new ion mobility mass spectrometry (IM-MS) method that enabled them to obtain mass spectra of folded protein conformations bound to lipids. Using this method they identified lipids that altered the stability of MscL (mechanosensitive channel of large conductance), aquaporin Z and the ammonia channel. They then determined the X-ray crystal structure of the ammonia channel bound to one of these lipids (phosphatidylglycerol), which revealed how a conformational change in a specific loop led to the formation of a phosphatidylglycerol-binding site. The major conclusion from this work is that an individual lipid-binding event can change the stability of a membrane complex. On the cover, IM-MS captures a native membrane protein complex emerging from an ion mobility cell. Shown is the ammonia channel in apo, one- and two-lipid bound states. Cover: Arthur Laganowsky.
From the Art Desk:
Art Director, Kelly Krause, explains:
“This dynamic cover was created by Art Laganowsky, one of the authors of the paper, using Blender software. The image nicely distills a rather complex paper into a clear, representational snapshot. The wires and hardware immediately give away that the paper is about methods and technological breakthrough (ion mobility mass spectrometry), while the structures and lipids moving through the ion mobility cell tells the rest of the story.”