Lähdesmäki P, Winter R
Acta Chem Scand B. 1977;31(9):802-6. doi: 10.3891/acta.chem.scand.31b-0802.
Free amino acids and other amino compounds in calf brain synaptic vesicles were identified and determined by thin-layer chromatography and ion-exchange chromatography. The vesicles contained ten identified amino acids with glutamic acid, aspartic acid, taurine and gamma-aminobutyric acid in the highest concentrations, and also cysteic acid (or cysteinesulfinic acid), glutamine, alanine, serine, glycine and lysine. The vesicles also contained certain unknown acid-labile, ninhydrin-positive compounds, one of which was a peptide yielding, after acid hydrolysis, about 40% aspartic acid, 30% serine, 15% glutamic acid, 10% glycine and possibly some alanine and lysine. The concentration of the peptide in the vesicles was as high as that of all the other amino compounds together.
