Use of mass spectrometric methods for protein identification in receptor research

In recent years, mass spectrometry has become the method of choice for iden tifying small amounts of gel separated proteins. Using high mass accuracy p eptide mass mapping followed if necessary by nanoelectrospray sequencing, m ost mammalian proteins can now be identified quickly and sensitively either in amino acid or in EST sequence databases. These methods are illustrated here using an ongoing project in the author's laboratory, a mass spectromet ric screen for new mouse brain receptors and their interaction partners.