Preparation And Identification Of DPP-Ⅳ Inhibitory Peptide And Its Effect On The Intestinal Microecology Of Diabetic Mice

In this study,computer simulation analysis and enzymatic hydrolysis were used to extract DPP-Ⅳ inhibitory peptides stored in donkey blood hemoglobin sequence.After ultrafiltration and dextran gel column chromatography were used to separate and purify the enzymatic hydrolysate,mass spectrometry and molecular docking were combined to identify the sequence of the DPP-Ⅳ inhibitory peptide,and the activity was verified after solid-phase synthesis of two DPP-Ⅳ inhibitory peptides.A mouse model of type Ⅱ diabetes was established to evaluate the hypoglycemic effect of DPP-Ⅳ inhibitory peptide derived from donkey blood on mice.16 S r RNA sequence and GC-MS comics were used to explore its effect on the intestinal microecology of diabetic mice.The main results of this study were as follows :1.Proteinase K enigmatically hydrolyzes donkey hemoglobin,the enzymatic hydrolysis conditions were: substrate mass concentration 1g/100 m L,time 3.15 h,temperature 65℃,p H 8,add enzyme amount 503 U/g,enzymatic hydrolysate(2mg/m L)The inhibition rate of DPP-Ⅳ was 53.44%.2.Two solid-phases synthesized DPP-Ⅳ inhibitory peptides were VDPENFRLL and YPWTQ,respectively.The binding energy of molecular docking simulation and DPP-Ⅳ enzyme: VDPENFRLL(-8.70)>YPWTQ(-9.10),IC50 value: VDPENFRLL(3.68±0.76 mg/m L)>YPWTQ(0.39±0.65 mg/m L),which indicated that YPWTQ has a strong inhibitory effect on DPP-Ⅳ enzyme.3.The active peptides in different dose groups can reduce the fasting blood glucose level of type Ⅱ diabetic mice and increase the glucose tolerance compare to the normal group,the liver and pancreas tissues of the model group have undergone a certain degree of pathological structural changes.After polypeptide intervention,the pathological damage to the two was repaired to a certain extent,and the effect of the high-dose active peptide group was the most obvious.4.The active peptide had a regulating effect on the intestinal microecology of diabetic mice.It can improve the intestinal micro ecology of diabetic mice by increasing the diversity of intestinal flora,the abundance of beneficial bacteria,and increasing the content of lactic acid.