Study on separation and physicochemical properties of ACE inhibitory peptides from porcine hemoglobin

The pepsin hydrolysate of porcine hemoglobin as raw material was used for adsorption and desorption through using macroporous resin DA201-C and Sephadex LH-20 chromatogram, then three antihypertensive components were obtained;and to collect and to study on physicochemical properties of ACE inhibitory peptideα-Ⅱthat possessing the largest ACE inhibitory activity.The results showed that:ACE inhibitory peptide of porcine hemoglobin was separaed by macroporous resin DA201-C and the IC₅₀ was 0.87mg/mL;next separaed by Sephadex LH-20 and IC₅₀ was 0.21mg/mL.The lowest solubility of ACE inhibitory peptides of porcine hemoglobin (α-Ⅱ) was 50.37%at pH 7;and this fraction (α-Ⅱ) demonstrated high stability against gastrointestinal proteases, temperature 25～55℃and pH<7.But ACE inhibitory activity could reduce rapidly when the NaCl concentration exceeded 0.6mol/L.