It is planned to apply the mass spectrometric amino acid sequencing technique developed in the earlier phases of this research grant to the determination of the structure of small proteins like the sweet monellin and the gamma phage repressor (about 90 and 250 amino acids long, respectively). The technique involves the reduction of the complex mixture of hydrolysis peptides, after N-trifluoro-acetylation and esterification to polyamino alcohols which, after O-trimethyl-silylation, are identified in a single gas chromatographic-mass spectrometric (GC-MS) experiment. In the course of this work, the technique will be further improved by the use of capillary columns and computer-aided interpretation of the data.