Isolation of Peptides from Calf Brain Tissue and Evaluation of their Tissue-Specific and Stimulatory Activity

Abstract

A method for separating a mixture of calf brain peptides by extraction with aqueous HOAc followed by fractionation of the extract by cross-flow (tangential) microfiltration and solid-phase extraction was developed. The isolated peptide mixture contained constituents with molecular masses within 0.1 – 3 kDa. Low-pressure ion-exchange chromatography of this mixture over Dowex 50WX8 sulfonated cation exchanger isolated a pure peptide consisting of the five amino acids Arg, Lys, Gly, Ser, and Leu. The biological activity of the obtained pentapeptide was estimated on organotypic brain slice culture explants of Wistar rats. It was established that the peptide possessed high tissue-specific and stimulatory activity for brain explants that was greater than those of the commercial preparations Cortexin and Cerebrolysin.