South Korean scientists have discovered a new three-dimensional structure and mechanism of a cell membrane protein which causes epilepsy and disorders of muscle.
Lim Hyun-ho, a senior researcher at the Korea Brain Research Institute (KBRI), announced on Aug. 21 that his team has discovered the new structure of outer glutamic acid residues which play a crucial role in deionization from a single CLC translocator protein.
A neuron, or nerve cell, controls physiological phenomena such as electrical signal transduction and signal transmitter secretion, by exchanging chlorine ion (Cl-) and hydrogen ion (H+) in cell membranes. If a problem arises in CLC translocator protein that engages in the process, it can lead to disorders of muscle, epilepsy, and hearing and sight loss.
The research team produced the mutant of CLC protein changing outer glutamic acid residues and studied their structure in nine different conditions. It also discovered a new part in the translocator where CI- combines. Based on this, it found that a single CLC protein can have four structural diversities in the ion exchange process.
Roderick MacKinnon, a professor of molecular neurobiology and biophysics at Rockefeller University who won the Nobel Prize in Chemistry together with Peter Agre in 2003 for his work on the structure and operation of CLC protein, predicted that this protein can have more than three structural diversities but less than two structures have been reported in same species until now.
The findings were published in the August edition of the international journalProceedings of the National Academy of Sciences (PNAS).