Opioid peptide for source of Alphas1-casein and preparation method thereof

Abstract

The invention discloses an opioid peptide for source of Alphas1-casein and a preparation method thereof. The preparation method comprises the following steps: pepsin is added into substrate, the pH value is adjusted to 2.0, enzymolysis is carried out to the obtained mixture for 2.5h at the temperature of 42 DEG C; wherein the substrate is Alphas1-casein solution with the concentration of 3 percent (w / v); the proportion of the pepsin and the Alphas1-casein is 1:30 (w / w); the enzymatic hydrolyzate adopts alcohol with the concentration of 80 percent for settling foreign protein, and the supernatant fluid is taken; and then a SephadexG-50 chromatography column is selected to carry out separation and chromatography to the supernatant fluid so as to collect a third peak. Fine separation and chromatography are carried out to the collected fluid by a SephadexG-15 chromatography column so as to collect a fourth peak; and after freeze-drying, the opioid peptide for source of Alphas1-casein is obtained. The obtained opioid active peptide corresponds to 144-158 sequence YFYPE LFRQFYQLDA of the Alpha-S1-casein, the molecular weight is 2252.48. The peptide can restrict autonomous contraction of ileum and has obvious effects of analgesis and fatigue resistance.

Description

technical field [0001] The invention relates to the field of biopharmaceuticals, in particular to an opioid peptide (AOPP) derived from αs1-casein. Background technique [0002] Milk is the usual source of exogenous opioid peptides. Generally, the opioid peptides from casein are called casomorphin (CM), and the opioid peptides from whey protein are called lactorphins. In 1979, Brantl et al. first reported that a short peptide with morphine-like activity was found in the capillaries of guinea pigs fed with bovine milk casein hydrolyzate. They first isolated it from the enzymatic hydrolyzate of β-casein A heptapeptide substance (Tyr-Pro-Phe-Pro-Gly-Pro-Ile) is the 60-66 amino acid residue fragment of β-casein, named β-casomorphin-7 (β-CM-7), It has a good affinity with μ receptors and exhibits the characteristics of opioid peptides, such as dependence and respiratory inhibition. Subsequently, β-CM-7 and its homologues β-CM-6, β-CM-5, and β-CM-4 were artificially synthesized,...

AI Technical Summary

Problems solved by technology

In the same year, Liang J et al. reported that an opioid peptide was isolated from hard lice with the sequence Leu-Val-Val-Tyr-Pro-Trp-Thr-Lys-Met, but because this substance was previously extracted from mammalian hemoglobin The opioid peptide hemorphin has a great sequence similarity, and scabies are blood-sucking animals, so whether this peptide is produced by scabies itself or obtained from the host when sucking blood remains to be further studied

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