A novel peptide sequence that is a modified derivative of a neuron-specific tyrosine phosphatase is shown and described. Specifically, the novel peptide sequence is a modified derivative of striatal-enriched tyrosine phosphatase (STEP). The peptide sequence has been modified so as to be able to ameliorate and treat brain injury resulting from excessive glutamate release and / or oxidative stress. Examples of the types of brain injury which the presently disclosed peptide sequence is useful for treating includes acute brain injury resulting from stroke or traumatic brain injury and chronic disorders such as Huntington's chorea and schizophrenia. Furthermore, the presently described peptide sequence may further be useful in the treatment and amelioration of disorders associated with fear memory such as post-traumatic stress disorder.
