MacKinnon, MD, a professor at Rockefeller University and an investigator at the Howard Hughes Medical Institute is a winner of the 1999 Albert Lasker award in basic medical research. The citation reads "For elucidating the functional and structural architecture of ion channel proteins, which govern the electrical potential of membranes throughout nature, thereby generating nerve impulses, and controlling muscle contraction, cardiac rhythm, and hormone secretion."
Nature Vol 401, 30 September 1999 on page 414 says of this work "He (MacKinnon) produced the first molecular description of an ion-selective channel. His 1998 paper in Science (3 April 1998 issue) on the crystal structure of potassium channels was a crucial step forward for this field and sparked much new research"
K Channel structure: Above is a ball and stick model showing the potassium channel structure with a potassium ion caught in the middle (center red ball). The x-ray diffraction data was collected at CHESS station A1 with special help from the MacCHESS staff. The flow of the potassium ions constitutes an electrical current in response to nerve cell activity. Prof. MacKinnon’s group now has this three-dimensional view of this structure and of ions in transit through the membrane. He is now trying to explain the channel affinity for potassium ions and the rejection of sodium ions that are always present around cellular membranes.
Science magazine (Vol 282, 18 December 1998, page 2158) cited the structure of the K+ channel as "one of the breakthroughs of 1998" and "the first physical characterization of the membrane protein responsible for the selective movement of K+ into and out of cells". F. Bloom, Editor-in-Chief of Science goes on to say "After decades of wondering, electrophysiologists can now understand such riddles as how the potassium channel manages to keep out wrong ions, such as sodium, while shuttling an amazing 100 million potassium ions per second across the membrane. The structure reveals that the ions must pass through a narrow filter, where potassium ions fit snugly and briefly bind to the protein. The slightly smaller sodium ions cannot form this bond, making the filter an energetically unattractive place for them… Membrane proteins are notoriously difficult to crystallize, but this year’s triumph may prompt work on the thousands of other such proteins still waiting."