Abstract

Oligopeptides exist in mammalian brain in a variety of forms, and represent the most numerous of the neurotransmitter and neuromodulator candidates. Most of these peptides are relatively small, ranging from three to approximately 40 amino acids in length. As such, they are relatively simple to synthesize in the laboratory using solid-phase peptide synthesis. Such syntheses have produced large numbers of analogues that are more potent or more stable than the native peptides, or may be specific antagonists at the peptide receptors. All of these neuropeptides are derived from large molecular weight protein precursors, which are cleaved into active products by the action of specific proteases. Many of the native peptides are extraordinarily potent in affecting different aspects of brain function, and have been implicated in central nervous system (CNS) disorders involving areas like Alzheimer's disease, control of appetite, clinical depression, and pain. A brief discussion of the various groups of brain oligopeptides is presented.