Carnitine palmitoyltransferase-1c, Cpt1c, is an enigmatic neuron-specific protein with no definitive function although it retains high sequence similarity to other known carnitine acyltransferases. To gain insight into the function of Cpt1c in neurons, an immuneprecipitation mass spectrometry screen was performed to identify new binding partners to inform cellular pathways relevant to Cpt1c. Therefore, lysate from the brains of transgenic mice that express an epitope-tagged Cpt1c where immunoprecipitated and binding partners eluted and identified by mass spectrometry. 5-oxoprolinase, Oplah, was identified as a Cpt1c-binding partner in vivo. These data support a possible role of Cpt1c in cellular redox metabolism.