Preparation Of Conglycinin Enzymatic Peptide And Its Effect On Intestinal Function Immunity In Mice

Soybean storage proteins are composed mainly of two major components, conglycinin and glycinin. The hydrolysate of conglycinin has a variety of physiological abilities demonstrated by some experiments, such as antihyprtensive, immunostimulating and antioxide activities. In the study, used 5 commercially available proteases with different origin and property to hydrolyze the conglycinin in vitro. Then isolated and identified the conglycinin peptides that selectively inhibit the growth of Escherichia coli and Staphylococcus aureus in vitro. In the study, evaluate the effects of soybean conglycinin peptides on immunity and gut ecolosystem of intestine.1.Study on enzymatic hydrolysis of conglycinin by various proteasesIn this study, 5 commercially available proteases with different origin and property were applied to hydrolyzed conglycinin. The most suitable protease was selected from above 5 proteases by comparing the hydrolytic efficiency of hydrolysis. Results showed that Flavourzyme was most suitable. The optimum condition of hydrolyzing conglycinin set as follows: 50℃,pH 7.0,substrate densiey 14% enzyme-substrate ratio 6.0%, hydrolyzing time 8h.2.Separation and determination of growth-inhibiting peptides for bacteria from soybean conglycininIn this study, bioactive peptides were prepared by hydrolyzing conglycinin with flavourzyme under different time conditions and the product was isolated by means of Sephadex-G15 gel chromarography. The results showed that 2h hydrolyzing peptides exhibited inhibitory activity to Escherichia coli and Staphylococcus aureus growth. The minimal inhibitory concent ration (MIC) of 2h hydrolyzing peptides against Escherichia coli and Staphylococcus aureus was 2.6mg/ml and 3.2mg/ml respectively. Components of 2h hydrolyzing peptides were separated using Sephadex-G15 gel filtration chromatography, tracking the maximum growth inhibitory activity of the resulting fractions on Escherichia coli and Staphylococcus aureus. Results of Bacterial growth assays showed that CP2 had the maximum growth inhibitory activity on Escherichia coli.3.Effects of hydrolysates from conglycinin with flavourzyme on Immune function in miceThe aim of this research was to elucidate effects of hydrolysates from conglycinin with flavourzyme on immune function in mice. Fifty male KM mice were randomly assigned to one of five treatments: Group I and Group II: Basal diet + physiological saline, Group III: Basal diet +Ampicillin, Group IV: Basal diet+flavourzyme-hydrolysate conglycinin, (V) Basal diet + purified fraction CP2 of flavorzyme hydrolysates of conglycinin. Feeding level of every mouse was 0.2ml with equal amount of nitrogen (0.1mg) except for group I, II and III. After fed 7 days, every mouse from II to V treatment was fed E.coli(O138). The level of every mouse is 0.2ml with E.coli (O138) 1×108 CFU/ml respectively. The result demonstrated that flavourzyme-hydrolysate conglycinin could significantly increase the level of spleen IL-2, increased the intestinal sIgA concentration, significantly decreased spleen TNF-αlevel. From the study above, we can conclude that hydrolysates from conglycinin with flavourzyme could increase the immune function in mice , defend the invasion of E.coli,and keep the gut healthy.