Biological Activity Of Wheat Germ Polypeptide Prepared By Complex Enzymes

In this paper, it was taken to prepare wheat germ polypeptide using multiplexenzymes hydrolyzed wheat germ, determination of the molecular weight distribution ofthe polypeptides, according to the result, wheat germ polypeptide was fragmented anddesalted by ultrafiltration membranes and nanofiltration membranes.Get the wheat germpeptides with different molecular weight; Study on wheat germ peptide biologicalactivities, including antioxidant, antifatigue, cholesterol-lowering activity, wheat germpeptide fragments obtained with good biological activity.(1)The molecular weight distribution of wheat germ peptides was determined by gelfiltration SephadexG-15.The results showed that molecular weight of polypeptidehydrolyzed by multiplex enzymes mainly concentrated between300-2000Da, accountedfor59%of the total area of the elution peaks, and accounted for28%was greater than2000Da,1000-2000Da was accounted for15%,600-1000Da was accounted for26%;300-600Da was accounted for19%; accounted for14%of peptides and amino acids wasamount of300Da. Based on the results, wheat germ polypeptide was fragmented anddesalted by ultrafiltration membranes and nanofiltration membranes.(2)Antioxidant activity of polypeptides with different molecular weightsOxidative damage mouse models were established and170mice were randomlydivided into17groups (normal control group, model control group, wheat germpolypeptide groups with different molecular weights and different concentrations. Exceptthe normal control group, all the mice were injected with D-galactoseat a dosage of600mg/(kg·d) to establish oxidative damage model. The mice in polypeptides groups wereadministered with polypeptides with five molecular weights at low, medium and highdoses. Forty days later, the mice were sacrificed and exsanguinated from eyeballs, andsuperoxide dismutase (SOD) activity, glutathione peroxidase (GSH-Px) activity,malondialdehyde (MDA), and total antioxidant capacity (T-AOC) in serum and liver weredetermined to explore antioxidant activity of wheat germ peptides. The results showedthat wheat germ peptides could improve the activities of SOD and GSH-Px as well asT-AOC in serum and liver, and reduce MDA level in serum and liver, suggesting goodantioxidant activity. In addition, increasing the peptide concentration could also improvethe antioxidant activity. Moreover, wheat germ peptides with molecular weight of1000Drevealed better antioxidant activity. (3)Effect of anti-fatigueResearch the effect anti-fatigue effect of wheat germ peptide, included animalendurance test: wheat germ peptides with different concentration gavage in mice, takingswimming and climbing pole test. Hypoxia tolerance test: wheat germ peptides withdifferent concentration gavage in mice, take normal pressure hypoxia toleranceexperiment and acute cerebral ischemic experiment. The anti-fatigue effect in vivo: themain purpose is to study on effects of wheat germ peptides on blood biochemical ofexercised mouse, included: determination of blood lactic acid and liver glycogenassay.The results show that:200-1000mg/(kg bw·d) of wheat germ peptides with differentmolecular weight has extended time of the mice climbing pole and swimming,suppressedactivity of lactic acid content in blood after mouse exercise, And maintain the content ofliver glycogen after exercise,etc. And in this range, the effect of high dose was better thanthe low dose. For wheat germ peptides with different molecular weight, effect of MPT-3(600-1000Da), MPT-4(300-600Da), MPT-5(less than300Da) was better than group ofMPT-1(more than2000Da), MPT-2(1000-2000Da). Wheat germ peptides can prolongthe time of normal pressure anoxia significantly, in the dose range of200-1000mg/(kgbw·d) had notable effect, and effect of polypeptide with molecular weight below1000Dawas more obviously.(4)The hypocholesterolemic activityStudy on the hypocholesterolemic activity of wheat germ peptides, preparation forsimulation bile micelle solution, simulating human intestinal environment in vitro, bymeasuring the solubility of cholesterol in bile in micellar solution.Wheat germ peptideswith different concentrations had inhibitory effect on cholesterol of system, cholesterolcontent of low molecular peptide group MPT-3, MPT-4and MPT-5group after simulatedbile micelle compared with MPT-1significant difference (P<0.05). There is somerelationship between the content of cholesterol and molecular weight of polypeptides,with the molecular weight smaller, the content of cholesterol reduced in the system,Wheat germ peptides had obvious inhibiting effect on cholesterol, generally the inhibitionrate was about50%-60%, and the maximum of rate can up to57.3%. And lower of themolecular weight, and more obviously inhibition of cholesterol, the hypocholesterolemicactivity of MPT-4was best.