Isolation of high-purity peptide Val-Val-Tyr-Pro from Globin Peptide using MCI gel column combined with high-speed...

Peptides have gained increased interest over the past several decades because of their therapeutics. In this research, a strategy combining MCI gel column chromatography and high-speed countercurrent chromatography was developed for the separation of high-purity peptide Val-Val-Tyr-Pro from Globin Peptide. First, the fraction of Val-Val-Tyr-Pro mixtures with a purity of 15.8% was obtained by using MCI gel column with a mixture of ethanol/water (20:80, v/v/v). Then, the high-purity Val-Val-Tyr-Pro was separated by high-speed countercurrent chromatography with a aqueous two phase systems of ethanol/acetonitrile/iso-propyl alcohol/(NH₄ )₂ SO_{4 Saturated solution} /H₂ O (0.5:0.5:0.25:1.5:0.7,v/v). The ammonium sulfate from high-speed countercurrent chromatography fractions was removed from target compound by MCI gel column chromatography using ethanol/water in stepwise elution mode. A 78 mg of Val-Val-Tyr-Pro was successfully purified with the purities of 98.80% from 30 g crude Globin Peptide. The amino acid sequence of the Val-Val-Tyr-Pro was determined by electrospray ionization high resolution tandem mass spectrometry. The method presents a practical strategy for the large-scale separation of pure peptide Val-Val-Tyr-Pro from Globin Peptide, and provides a reference method for obtaining high-purity peptide from other polypeptide mixtures.