In this project we aimed to identify the spectrum of protein binders of nucleolin’s glycine arginine reach (GAR) domain. We did so by designing a 15 amino acid peptide derived from the GAR domain sequence, which includes 3 arginine-glycine-glycine (RGG) repeats and we call "R3". We conducted affinity purification with biotinylated R3 peptide, from mouse sciatic nerve axoplasm preparations, followed by mass spectrometry, in order to identify potential GAR interacting proteins.