WO-2026091162-A1 - BIOACTIVE PEPTIDE PCT-1, PREPARATION METHOD THEREFOR, AND USE THEREOF

Abstract

A bioactive peptide PCT-1, a preparation method therefor, and a use thereof, relating to the technical field of biology. The amino acid sequence of the bioactive peptide PCT-1 is LNRTFE, as shown in SEQ ID NO: 1 in a sequence listing, and the bioactive peptide PCT-1 has antioxidant and intestinal flora regulation functions. The bioactive peptide PCT-1 is extracted from a spirulina protein peptide and can significantly improve the activity of SOD and GSH-Px in serum and significantly reduce the content of MDA in the serum. The in vivo antioxidant activity of the bioactive peptide is equivalent to that of a positive control Trolox. Moreover, compared with a blank control group, the bioactive peptide PCT-1 can also reduce the α diversity index of the intestinal flora, change the overall structure of the intestinal flora, regulate the abundance of intestinal flora at various taxonomic levels, and significantly increase the content of acetic acid and butyric acid, and can be applied to foods having antioxidant and intestinal flora regulation functions.

Inventors

• LI, WENJUN
• CHE, Tuanjie
• QIN, SONG
• LU, CHENYANG
• XU, Jinzhang
• YAN, Libo
• XIE, Guizhen
• KAN, YING

Assignees

• 中国科学院烟台海岸带研究所
• 烟台至公生物医药科技有限公司

Dates

Publication Date

20260507

Application Date

20241106

Priority Date

20241029

Claims (4)

1. A bioactive peptide PCT-1, characterized in that the amino acid sequence of the bioactive peptide PCT-1 is LNRTFE, as shown in SEQ ID NO: 1 of the sequence listing, and has antioxidant and intestinal flora regulation functions.
2. The application of the bioactive peptide PCT-1 as described in claim 1 in antioxidant and gut microbiota-regulating functional foods.
3. The method for preparing the bioactive peptide PCT-1 according to claim 1 is characterized by employing a solid-phase synthesis method, specifically: Using Fmoc-protected amino acids as raw materials and polystyrene resin as a solid-phase carrier, solid-phase synthesis was carried out using the Fmoc solid-phase synthesis strategy.
4. The method for preparing the bioactive peptide PCT-1 according to claim 1 is characterized by employing an enzymatic hydrolysis method, specifically: (1) Take spirulina protein, add water at a mass ratio of 9 times that of spirulina protein, add compound protease at a ratio of 0.5% for enzymatic hydrolysis, the hydrolysis temperature is 55℃, the pH value is 8.0, the hydrolysis time is 6h, and the hydrolysis product is obtained. The compound protease is composed of alkaline protease and neutral protease mixed in a mass ratio of 1:1. (2) After the enzymatic hydrolysis is completed, the enzymatic hydrolysis product is filtered through eight layers of gauze to remove the residue and obtain the spirulina protein peptide hydrolysate. (3) Freeze-dry the above-mentioned Spirulina protein peptide hydrolysate to obtain Spirulina protein peptide powder, which contains a large amount of bioactive peptide PCT-1.

Description

A bioactive peptide PCT-1, its preparation method and application Technical Field This invention relates to a small molecule peptide, its preparation method, and its application. Specifically, it relates to a small molecule bioactive peptide PCT-1 with antioxidant and gut microbiota regulation functions, its preparation method, and its application in foods with antioxidant and gut microbiota regulation functions, belonging to the field of biotechnology. Background Technology Obesity, aging, and various diseases such as cancer, cardiovascular disease, and Alzheimer's disease have been proven to be closely related to the excessive production of free radicals. The normal body can regulate oxidative balance through various antioxidant mechanisms, including scavenging free radicals to block their chain reactions, chelating metal ions to inhibit free radical production, and regulating endogenous glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) to eliminate free radicals. When endogenous oxidative balance is disrupted, exogenous antioxidants are needed. Traditional antioxidants are generally chemically synthesized, which has disadvantages such as poor stability and strong toxicity. In contrast, antioxidant peptides derived from protein hydrolysis have advantages such as safety, non-toxicity, and high stability, making them more suitable for consumer demands. The human gut contains approximately 1,000 species and 100 trillion microorganisms, mainly including bacteria, yeast, and parasites. These gut microbes carry more than 100 times the number of genes in the human body, earning them the title of "invisible organ." Gut microbiota imbalance is closely related to obesity, hypertension, intestinal inflammation, and cardiovascular disease, and regulating gut microbiota is one of the functions permitted for health supplement claims in the "List of Permitted Health Functions for Health Foods (Non-Nutritional Supplements, 2023 Edition)." Besides directly supplementing with probiotics, bioactive peptides have also been reported to have gut microbiota-regulating functions. Attached Figure Description Figure 1 is a schematic diagram of the binding mode between the bioactive peptide PCT-1 and Keap1; Figure 2 is a partially enlarged schematic diagram of Figure 1; Figure 3 shows the effects of treatment with the bioactive peptide PCT-1 on physiological indicators in mice. In the figure, A shows the effect on weight gain in mice, B shows the effect on spleen coefficient in mice, and C shows the effect on liver coefficient in mice. * indicates P<0.05, and ** indicates P<0.01. Figure 4 shows the effect of treatment with the bioactive peptide PCT-1 on the antioxidant indicators of mouse serum. In the figure, A is the effect on mouse serum MDA content, B is the effect on mouse serum SOD activity, C is the effect on mouse serum CAT activity, and D is the effect on mouse serum GSH-Px activity. * indicates P<0.05, and ** indicates P<0.01. Figure 5 shows the effect of treatment with the bioactive peptide PCT-1 on the transcriptional level of the keap1 gene in mice. In this figure, A shows the effect on the transcriptional level of the keap1 gene in the mouse brain, and B shows the effect on the transcriptional level of the keap1 gene in the mouse liver. * indicates P<0.05, and ** indicates P<0.01. Figure 6 shows the effect of treatment with the bioactive peptide PCT-1 on the β diversity of the intestinal flora in mice. Figure 7 shows the effect of treatment with the bioactive peptide PCT-1 on the content of short-chain fatty acids in the mouse intestine. In the figure, A shows the effect on the content of acetic acid in the mouse intestine, B shows the effect on the content of propionic acid in the mouse intestine, and C shows the effect on the content of butyric acid in the mouse intestine. ** indicates P<0.01, and *** indicates P<0.001. Embodiments of the present invention The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. I. Preparation of Spirulina Protein Peptide Samples Spirulina was washed, dried, pulverized, and sieved sequentially to obtain spirulina powder. The spirulina powder was added to a 0.01M phosphate buffer solution (pH 6.8) at a ratio of 1 kg:10 L and thoroughly mixed in a granulator. Then, it was circulated and ground using a colloid mill. The resulting mixture was centrifuged to remove solid residue. The supernatant was filtered sequentially through a 25 μm filter cloth and a 0.45 μm filter membrane to obtain a crude spirulina protein extract. This crude extract was concentrated by ultrafiltration using ultrafiltration membranes with molecular weight cutoffs of 5 kDa and 10 kDa. The ultrafiltration fractions with molecular weights in the range of 5 kDa to 10 kDa were collected and spray-dried to obtain spirulina protein. Take spirulina protein and add 9 times the mass of water (the mass concentration of spirulina