Polypeptide for preventing and treating diabetes, preparation method and application thereof

The invention discloses chickpea four-type 37-amino acids polypeptides, a preparation method thereof and an application thereof in preparing a medicine for treating diabetes or a functional food. Eachpeptide is composed of 37 amino acids, the six cysteines in the molecule and the formed three pairs of disulfide bridges are highly conserved, and the three pairs of disulfide bonds form a cysteine knot domain. The chickpea four-type 37-amino acids polypeptides can be dissolved in polar solvents such as water, which are stable to heat and resistant to hydrolysis of protease in human digestive tract. The preparation cost is lower than that of insulin and other peptide drugs; the product is not only can be used for treating symptomatic doeases, but also treats the root, and can be used for recovering the quality and function of diseased pancreas at varying degrees; the product reduces or eliminates the body's insulin resistance, can be developed to oral dosage form, and is easier to use than insulin and other pepti