Ubiquitin carboxylterminal hydrolase isozyme L1 (UCHL1) ,a member of the peptidase C12 family, is also known as neuron cytoplasmic protein 9.5 (PGP 9.5) and ubiquitin thioesterase L1.About 30% of total UCHL1 is associated with membranes in brain. UCHL1 i