Analytic test and identification method of bio-active polypeptide

Abstract

The invention provides a method of identifying bio-active polypeptides in fermented milk. In the method, after effective pre-treatment to the fermented milk, a gastrointestinal tract digestion simulative test is carried out to ensure the bio-active polypeptides in the fermented milk and digested products thereof to be obtained as much as possible, and especially the polypeptides are low in concentration but have bio-activities can be obtained. In addition, the obtained polypeptide sequences have an effect of resisting hydrolysis at a certain degree, so that the obtained polypeptides are easier to absorb by human body and the bio-activities can be achieved better. Meanwhile, a method, in which a predicted sequence is obtained through molecular weight cooperation and calculation verification to predict the obtained polypeptide sequences, is established. Through the method, 119 polypeptides from milk proteins can be identified, comprising not only large amounts of the bio-active peptides which have been reported but also the bio-active peptides which are not reported in the prior art. The method can be universally used in analysis and identification of the bio-active polypeptides in a complex substrate such as fermented milk and the digested products thereof.

Description

technical field [0001] The invention relates to the field of proteins, in particular to a method for identifying biologically active polypeptides in fermented milk. Background technique [0002] In the commonly used methods for identifying bioactive peptides so far, it is usually guided by a certain biological activity. After each separation, the activity is identified and the active part is taken, separated and purified again, and finally the peptides in the highly active part of the product are identified. CristianDeGobba et al. identified antioxidant bioactive peptides derived from goat milk: first, the hydrolyzate was fractionated by size-exclusion chromatography, and the activity of each fraction was determined by a selected bioactivity assay method (such as: antioxidant activity in vitro); Then, the highly active part was further separated by semi-preparative reversed-phase high-performance liquid chromatography for activity determination; finally, the separated most a...

AI Technical Summary

Problems solved by technology

[0003] However, the strategy of bioactivity-dominated fractionation results in losses during each separation, thus ignoring some low-concentration active substances

In particular, yogurt produces a series of complex and diverse peptide mixtures during fermentation, derived from milk protein precursors in varying amounts, including αs1-casein, αs2-casein, β-casein, κ-casein, α - Lactalbumin, β-lactoglobulin and bovine serum albumin, the relative content ratio between them is about 30:30:10:12:10:4:1, so the traditional method is derived from low concentration of protein precursor Peptides are difficult to identify

Images