text: One group of researchers applied the field of neuroproteomics to examine how different proteins affect the initial growth of neuritis.  The experiment compared the protein activity of control neurons with the activity of neurons treated with nerve growth factor (NGF) and JNJ460, an “immunophilin ligand.”  JNJ460 is an offspring of another drug that is used to prevent immune attack when organs are transplanted.  It is not an immunosuppressant, however, but rather it acts as a shield against microglia.    NGF promotes neuron viability and differentiation by binding to TrkA, a tyrosine receptor kinase.  This receptor is important in initiating intracellular metabolic pathways, including Ras, Rak, and MAP kinase.
  Protein differentiation was measured in each cell sample with and without treatment by NGF and JNJ460.  A peptide mixture was made by washing off unbound portions of the amino acid sequence in a reverse column.  The resulting mixture was then suspended a peptide mixture in a bath of cation exchange fluid.  The proteins were identified by splicing them with trypsin and then searching through the results of passing the product through a mass spectrometer.  This applies a form of liquid chromatography mass spectrometry to identify proteins in the mixture
  JNJ460 treatment resulted in an increase in “signal transduction” proteins, while NGF resulted in an increase in proteins associated with the ribosome and synthesis of other proteins.  JNJ460 also resulted in more structural proteins associated with intercellular growth, such as actin, myosin, and troponin.  With NGF treatment, cells increased protein synthesis and creation of ribosomes.  This method allows the analysis of all of the protein patterns overall, rather than a single change in an amino acid.  Western blots confirmed the results, according to the researchers, though the changes in proteins were not as obvious in their protocol.
  	The main significance to these findings are that JNJ460 are NGF are distinct processes that both control the protein output of the cell.  JNJ460 resulted in increased neuronal size and stability while NGF resulted in increased membrane proteins.  When combined, they significantly increase a neuron’s chance of growth.  While JNJ460 may “prime” some parts of the cell for NGF treatment, they do not work together.  JNJ460 is thought to interact with Schwann cells in regenerating actin and myosin, which are key players in axonal growth.  NGF helps the neuron grow as a whole.  These two proteins do not play a part in communication with other neurons, however.  They merely increase the size of the membrane down which a signal can be sent.  Other neurotrophic factor proteomes are needed to guide neurons to each other to create synapses.