Mass spectral and hydrolytic determination of amino acid sequences in synaptosomal peptides from calf brain.

Calf brain synaptosomes contained acidic peptides, which could be separated into two spots with two-dimensional thin-layer chromatography. These two spots contained several peptides or their partial degradation products. Mass spectrometry and various hydrolytic procedures were used in order to determine their amino acid sequences. The following original structures could be identified: N-acetyl-aspartyl-glutamyl-taurine, N-acetylaspartyl-taurine, N-acetylglutamyl-taurine, aspartyl-taurine, glutamyl-taurine and seryl-taurine in one spot, and N-acetylaspartyl-glycyl-alanyl-aspartyl-serine or -phosphoserine, alanyl-glycyl-glutamyl-serine or -phosphoserine, glutamyl-alanyl-glycyl-glutamyl-serine, glutamyl-aspartyl-phosphoserine and glutamyl-seryl-seryl-alanyl-aspartic acid in the second spot.