Preparation method of high adsorption performance quinoa polypeptide aerogel
By predicting the easily fibrous amino acid sequence of quinoa protein and synthesizing quinoa polypeptide aerogel, the problem of insufficient adsorption capacity of plant protein aerogels for microplastics under neutral conditions was solved, achieving efficient and environmentally friendly removal of microplastics from water.
Patent Information
- Application Number
- CN202610518311.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-20
- Publication Date
- 2026-07-10
Smart Images
Figure CN122356565A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of bio-based materials, and in particular to a method for preparing quinoa polypeptide aerogel with high adsorption performance. Background Technology
[0002] Microplastics are recognized as a pervasive environmental pollutant, found in the atmosphere, soil, and aquatic ecosystems. Microplastics can cause oxidative stress, disrupt metabolism, interfere with the gut microbiota and gastrointestinal function, damage the heart, lungs, liver, and immune system, and affect reproductive health.
[0003] Aerogels can remove microplastics from water, such as dopamine / chitosan aerogels, reduced graphene oxide aerogels, and protein aerogels. Compared to expensive dopamine and reduced graphene oxide, plant proteins are cost-effective and biodegradable, but their gelling properties are weak. Methods should be sought to promote the fibrosis of plant proteins to improve their gelling properties, thereby constructing plant protein aerogels.
[0004] Currently, amyloid fibrous aggregates are mainly formed under pH 2 conditions. However, the fibrous aggregates obtained under these conditions are not stable enough, and their structure is easily affected by pH changes. In addition, strongly acidic conditions are also detrimental to environmental and food applications. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a method for preparing quinoa polypeptide aerogel with high adsorption performance and high adsorption capacity for microplastics in water.
[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: a method for preparing quinoa polypeptide aerogel with high adsorption performance, the innovation of which is: including the following steps: First, the WALTZ algorithm is used to predict and identify the amino acid sequence of easily fibrous quinoa polypeptide in quinoa protein fiber solution, and the amino acid sequence of easily fibrous quinoa polypeptide is obtained. Based on the amino acid sequence of quinoa polypeptide, the corresponding quinoa polypeptide is synthesized using the Fmoc solid-phase synthesis method. Then, the synthesized quinoa polypeptide is dissolved in water to form a quinoa polypeptide fiber solution. Finally, the quinoa polypeptide fiber solution is mixed with sodium alginate solution to prepare quinoa polypeptide aerogel.
[0007] Furthermore, the specific steps are as follows: S1: Prediction and identification of amino acid sequences of easily fibrozed quinoa polypeptides: First, the protein in the quinoa protein fiber solution was precipitated by the trichloroacetic acid precipitation method, and the protein precipitate was reconstituted by adding a reconstitution solution to obtain the sample solution. The reconstitution solution was a mixture of urea and Tris-HCl solution. Secondly, the protein concentration in the sample solution was determined by the dioctanine method. After taking an equal amount of protein to make up the same volume, the sample solution was subjected to a reduction alkylation reaction. Then, Tris-HCl solution was added to the sample solution after the reduction alkylation reaction to dilute the urea concentration in the sample solution. Then, trypsin was added to the sample solution, and the enzyme digestion was performed by shaking overnight at 37°C. The next day, trifluoroacetic acid was added to the sample solution to terminate the enzyme digestion. The supernatant was taken and desalted on a styrene-divinylbenzene-reverse-phase sulfonic acid-based desalting column. After vacuum drying, it was frozen at -20°C. Mass spectrometry data were acquired using a mass spectrometer-liquid chromatography-mass spectrometry system with a mass spectrometry scanning range of 350-1500 m / z. The identified peptides were then combined with the WALTZ algorithm to predict whether there were potentially fibrotic amino acid sequences in the peptides. Finally, the amino acid sequence of the fibrotic quinoa decapeptide was obtained, which is valine-isoleucine-serine-asparagine-isoleucine-tyrosine-glutamine-isoleucine-serine-arginine. S2: Synthesis of Quinoa Decapeptide: The Fmoc solid-phase synthesis method was adopted, starting with Fmoc-Arg(pbf)-WangResin. Through a four-step cycle of "de-wash-attach-wash", the Fmoc-protected amino acids were extended one by one from the C-terminus to the N-terminus and attached to the resin. Finally, the synthesized peptide was cleaved from the resin by TFA, and the side chain protecting groups of the amino acids were removed. The obtained peptide was purified by high performance liquid chromatography, lyophilized, and the sequence and molecular weight were verified by electrospray ionization mass spectrometry. The purity was analyzed by analytical HPLC. S3: Preparation of quinoa polypeptide fiber: Weigh quinoa decapeptide freeze-dried powder and disperse it in water to form a quinoa decapeptide solution. Place it in a water bath and heat it. After heat treatment, immediately cool it in an ice water bath to obtain a polypeptide fiber solution, and store it in a refrigerator at 4°C for later use. S4: Preparation of quinoa polypeptide aerogel: Sodium alginate powder was dispersed in water to form a sodium alginate solution with a final concentration of 20 mg / mL. The solution was magnetically stirred overnight to ensure full hydration. The polypeptide fiber solution and sodium alginate solution were added to a beaker and stirred to form a hydrogel. The hydrogel was soaked in a 10 mg / mL CaCl2 solution for 30 min, and then washed repeatedly with deionized water three times to remove excess calcium ions from the surface. Finally, the hydrogel was freeze-dried for 72 h to form the desired high-adsorption quinoa polypeptide aerogel.
[0008] Furthermore, in step S1, the reconstitution solution is a mixture of 8 mol / L urea and 100 mmol / L Tris-HCl solution, with a pH of 8.5. After the reductive alkylation reaction, 100 mmol / L Tris-HCl solution is added to the sample, and the concentration of urea in the sample needs to be diluted to below 2 mol / L.
[0009] Furthermore, in step S1, the mass ratio of enzyme to protein in the trypsin is 1:50.
[0010] Furthermore, in step S3, when weighing the quinoa decapeptide freeze-dried powder and dispersing it in water, the concentration of quinoa decapeptide in the water needs to reach 30 mg / mL, and the pH of the quinoa decapeptide solution needs to be adjusted to 7.0.
[0011] Furthermore, in step S3, the temperature of the water bath is 95°C, and the heating time in the water bath is 30 minutes.
[0012] Furthermore, in step S4, when adding the polypeptide fiber solution and sodium alginate solution to the beaker, the polypeptide fiber solution and the polypeptide fiber solution and sodium alginate solution are added to the beaker in the order of mass ratio 1:1, 2:1, and 3:1, respectively.
[0013] The advantages of this invention are as follows: This invention uses the WALTZ algorithm to predict the potential amino acid sequence in quinoa protein that is prone to forming protein fibers, and uses the Fmoc solid-phase synthesis method to synthesize quinoa decapeptide, and fully verifies the high fiberization ability of quinoa decapeptide, realizing the efficient preparation of quinoa decapeptide amyloid fibers under neutral conditions, and based on this, prepares quinoa decapeptide-sodium alginate composite aerogel with high adsorption performance for microplastics in water.
[0014] The high-adsorption-performance quinoa polypeptide aerogel prepared in this invention exhibits superior adsorption capacity and removal rate for microplastics in water compared to dopamine and reduced graphene oxide aerogels. Furthermore, the quinoa polypeptide aerogel, using quinoa polypeptides as raw material, demonstrates a green and environmentally friendly preparation process. Through the synergistic effect of physical retention and chemical adsorption, it achieves high adsorption capacity and removal rate for microplastics in water. The material is a block-shaped monolithic material, making it easy to separate and recover from water after adsorption, thus avoiding secondary pollution. It is also biodegradable, highly environmentally friendly, and has broad application prospects in the field of water treatment. Attached Figure Description
[0015] Figure 1 , Figure 2 These are morphological images of quinoa decapeptide amyloid fibers at different concentrations in this invention.
[0016] Figure 3 , Figure 4This is a schematic diagram showing the outline length distribution of quinoa decapeptide amyloid fibers at different concentrations in this invention.
[0017] Figure 5 This is a schematic diagram of the microstructure of aerogels with different ratios of quinoa decapeptide amyloid fibers and sodium alginate before and after adsorbing microplastics, as described in this invention.
[0018] Figure 6 The aerogel FTIR spectra of different ratios of quinoa decapeptide amyloid fiber and sodium alginate in this invention are shown.
[0019] Figure 7 This is a comparison of the adsorption capacity of aerogels with different mass ratios of quinoa 11S globulin fibers to chitosan for microplastics in Examples 2 and 3 of this invention. Detailed Implementation
[0020] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.
[0021] The preparation method of the high-adsorption-performance quinoa polypeptide aerogel of the present invention is achieved through the following steps: First, the amino acid sequence of easily fibrous quinoa polypeptides in quinoa protein fiber solution is predicted and identified using the WALTZ algorithm to obtain the amino acid sequence of easily fibrous quinoa polypeptides. Based on the amino acid sequence of quinoa polypeptides, the corresponding quinoa polypeptides are synthesized using the Fmoc solid-phase synthesis method. Then, the synthesized quinoa polypeptides are dissolved in water to form a quinoa polypeptide fiber solution. Finally, the quinoa polypeptide fiber solution is mixed with sodium alginate solution to prepare quinoa polypeptide aerogel.
[0022] The following is in conjunction with the appendix Figure 1-7 The preparation method of the high-adsorption-performance quinoa polypeptide aerogel of the present invention is further described below: Example 1
[0023] S1: Prediction and identification of amino acid sequences of easily fibrotic quinoa polypeptides: First, the protein in the quinoa protein fiber solution was precipitated using the trichloroacetic acid precipitation method. Then, a reconstitution solution was added to the obtained protein precipitate for reconstitution. The reconstitution solution was a mixture of 8 mol / L urea and 100 mmol / L Tris-HCl solution. Tris-HCl is tris(hydroxymethyl)aminomethane hydrochloride. The pH of the reconstitution solution was 8.5, and the sample solution was obtained.
[0024] Secondly, the protein concentration in the sample solution was determined by the dioctylcarboxylic acid method. After taking an equal amount of protein to make up the same volume, the sample solution was subjected to a reduction alkylation reaction. Then, 100 mmol / L Tris-HCl solution was added to the sample solution after the reduction alkylation reaction to dilute the urea concentration in the sample solution until the urea concentration in the sample solution was diluted to below 2 mol / L.
[0025] Then, trypsin was added to the sample solution at a mass ratio of 1:50 to the protein. The digestion was performed overnight at 37°C with shaking. The next day, trifluoroacetic acid was added to the sample solution to terminate the digestion. The supernatant was then desalted using a styrene-divinylbenzene-reverse-phase sulfonic acid-based desalting column. After vacuum drying, the sample was frozen at -20°C. Mass spectrometry data were acquired using a liquid chromatography-mass spectrometry (LC-MS) system with a mass spectrometry scanning range of 350-1500 m / z. The identified peptides were then combined with the WALTZ algorithm to predict whether there were potentially fibrotic amino acid sequences in the peptides. Finally, the amino acid sequence of the fibrotic quinoa decapeptide was obtained, which is valine-isoleucine-serine-asparagine-isoleucine-tyrosine-glutamine-isoleucine-serine-arginine.
[0026] S2: Synthesis of quinoa decapeptide: The Fmoc solid-phase synthesis method was adopted, starting with Fmoc-Arg(pbf)-WangResin. Through a four-step cycle of "de-wash-attach-wash", the Fmoc-protected amino acids were extended one by one from the C-terminus to the N-terminus and attached to the resin. Finally, the synthesized peptide was cleaved from the resin using TFA (trifluoroacetic acid). The TFA simultaneously removed the side chain protecting groups of the amino acids. The obtained peptide was purified by high performance liquid chromatography, lyophilized, and the sequence and molecular weight were verified by electrospray ionization mass spectrometry. The purity was analyzed by analytical HPLC.
[0027] S3: Preparation of quinoa polypeptide fiber: Weigh out quinoa decapeptide lyophilized powder and disperse it in water to form a quinoa decapeptide solution. The concentration of quinoa decapeptide in the water needs to reach 30 mg / mL. Adjust the pH of the quinoa decapeptide solution to 7.0 and place it in a water bath at 95°C for 30 min. Immediately after heat treatment, cool it in an ice-water bath to obtain a polypeptide fiber solution, which is then stored in a refrigerator at 4°C for later use.
[0028] S4: Preparation of quinoa polypeptide aerogel: Sodium alginate powder was dispersed in water to form a sodium alginate solution, and the final concentration of sodium alginate in the solution was controlled to reach 20 mg / mL. The solution was magnetically stirred overnight to ensure full hydration. The polypeptide fiber solution and sodium alginate solution were added to beakers at mass ratios of 1:1, 2:1, and 3:1, respectively, and stirred to form a hydrogel. The hydrogel was soaked in 10 mg / mL CaCl2 solution for 30 min, and then washed repeatedly with deionized water three times to remove excess calcium ions from the surface. Finally, the hydrogel was freeze-dried for 72 h to form the desired high-adsorption quinoa polypeptide aerogel.
[0029] Following the steps described above, samples of pure sodium alginate aerogel and pure polypeptide fiber were prepared separately. The pure sodium alginate aerogel sample was prepared without fiber solution, and the pure polypeptide fiber sample was prepared without sodium alginate. Other preparation methods were the same as those described above. Example 2
[0030] Without performing steps S1 and S2, in step S3, quinoa 11S globulin is directly used as the raw material to prepare quinoa 11S globulin fiber solution with a concentration of 30 mg / mL. In step S4, without adding sodium alginate, aerogel is prepared directly by freeze-drying the protein fiber solution for 72 h. Example 3
[0031] Similarly, steps S1 and S2 are omitted. In step S3, quinoa 11S globulin is directly used as the raw material to prepare quinoa 11S globulin fiber solution with a concentration of 30 mg / mL. In step S4, 800 mg of chitosan powder is dissolved in 20 mL of acetic acid aqueous solution with a concentration of 30 mL / L until the solution becomes clear, resulting in a chitosan solution with a final concentration of 40 mg / mL. Then, the prepared quinoa 11S globulin fiber solution and chitosan solution are mixed sequentially at mass ratios of 1:1, 2:1, and 3:1. Each mixture is added to a glutaraldehyde solution (2%, v / v) using a syringe, stirred evenly, and incubated overnight at 4°C to form a composite hydrogel. Finally, each hydrogel is further soaked in a glutaraldehyde solution with a concentration of 20 mL / L for 12 h for fixation. After washing with deionized water, the hydrogel is placed in a -80°C freezer and then freeze-dried for 72 h to obtain the desired aerogel.
[0032] The aerogels prepared in Examples 1, 2, and 3 were used to adsorb microplastics in water, and the adsorption results are as follows: Figure 7 As shown, from the appendix Figure 7 The comparison shown indicates that the adsorption capacity of Examples 2 and 3 is much lower than that of Example 1.
[0033] To further demonstrate the advantages of this invention, a comparative analysis was conducted on quinoa polypeptide amyloid fiber aerogels with different mass ratios of quinoa decapeptide amyloid fiber and sodium alginate. The results are as follows: Sample preparation and processing Quinoa decapeptide amyloid fiber samples were prepared according to the procedure in step S2 above, and quinoa decapeptide amyloid fiber aerogel samples were prepared according to the procedure in step S3 above. The obtained quinoa decapeptide amyloid fiber samples were placed in a room temperature drying oven for later use.
[0034] 2. Transmission electron microscopy was used to verify the formation of quinoa decapeptide amyloid fibrils. Using the quinoa decapeptide amyloid fiber sample obtained above, a 0.05% (w / v) quinoa decapeptide amyloid fiber sample solution was prepared. Then, 10 μL of the quinoa decapeptide amyloid fiber sample solution and 4 μL of phosphotungstic acid (2%) were added dropwise onto a carbon film on a special copper mesh. After 30 s and 1 min, respectively, the excess solution was absorbed with filter paper. Transmission electron microscopy images of quinoa decapeptide amyloid fiber aggregates were obtained using a 120 kV transmission electron microscope, and the length of the amyloid fibers in the images was statistically analyzed.
[0035] 3. Amyloid fiber conversion rate of quinoa decapeptide The quinoa decapeptide amyloid fiber sample solution was diluted to 2 mg / mL. Then, 40 μL of 2% (w / v) trypsin (enzyme activity ≥ 250 units / mg protein) was added to the quinoa decapeptide amyloid fiber sample solution. The sample solution was placed in a shaker at 37℃ and 150 rpm for 4 h. PMSF (phenylmethyl sulfonyl fluoride) was then added to inhibit enzyme activity. The resulting sample (2 mg / mL) was added to an ultrafiltration tube with a fraction cutoff of 100 kDa. The sample was centrifuged at 3000g for 15 min. The filtrate after centrifugation was designated "fraction 1". The filtrate was washed twice with ultrapure water, and the resulting filtrates were designated "fraction 2" and "fraction 3". After measuring the filtrate volume, the protein concentration of each component was determined at 280 nm using a UV-Vis spectrophotometer. A standard curve was prepared using different concentrations of bovine serum albumin. The conversion rate was calculated using the following formula: In the above formula, F(g) is the protein content of the diluted sample, and F1, F2, and F3(g) are the protein contents of fraction 1, fraction 2, and fraction 3, respectively.
[0036] 4. Morphology and microstructure of quinoa decapeptide amyloid fiber aerogel Quinoa decapeptide amyloid fibrous aerogel samples were cut into cubes, each measuring 0.5 × 0.5 × 0.5 cm. 3 Quinoa decapeptide amyloid fiber aerogel samples were attached to the sample stage with conductive adhesive and sputtered with gold. Finally, the cross-sectional structure of the gel samples was observed and photographed under a scanning electron microscope at 20kV.
[0037] 5. Intermolecular force analysis between quinoa decapeptide amyloid fibers and sodium alginate The secondary structure of quinoa decapeptide amyloid fiber aerogel samples was determined by FTIR. Appropriate amounts of lyophilized sample and dried potassium bromide were pressed into thin sheets using a tablet press. Each sample underwent full-spectrum FTIR (4000-4000 cm⁻¹). -1 Scan, resolution 4cm -1 .
[0038] 6. The gel's adsorption capacity for microplastics in water The adsorption kinetics of microplastics were tested at 25℃ and pH 7. Fluorescence of 50 mL polystyrene suspension was measured at 0, 1, 3, 5, 10, 20, 30, 60, 120, and 180 min using a fluorescence spectrophotometer. The particle size of the polystyrene suspension was 1 μm, and the concentration was 0.1 mg / mL. The excitation and emission wavelengths were 488 nm and 518 nm, respectively. The adsorption capacity was obtained from the concentration change using the following formula: In this formula, q t The adsorption capacity at time t is expressed as (mg / g), C0 and C2. t Let m represent the initial and time t concentrations of microplastics (mg / mL), m be the weight of the aerogel (g), and V be the volume of the microplastic solution (mL).
[0039] 7. Statistical analysis and graphing Experimental data were analyzed using IBM SPSS Statistics 26. Results are expressed as mean ± standard deviation of at least three independent samples (p < 0.05). All images were generated using Origin 2018.
[0040] 8. Results and Analysis 1) Morphology of quinoa decapeptide amyloid fibers at different concentrations Figure 1 , Figure 2 The image shows the morphology of quinoa decapeptide amyloid fibers at different concentrations. When the concentration of quinoa decapeptide is 1.0 mg / mL, a large number of long, rigid amyloid fibers are formed after heating. Figure 3 , Figure 4The diagram shows the outline length distribution of quinoa decapeptide amyloid fibers. The length of the amyloid fibers formed by the self-assembly of quinoa decapeptide varies at different concentrations, and the amyloid fibers become longer as the concentration of quinoa decapeptide increases.
[0041] Table 1 shows the conversion rate of quinoa decapeptide amyloid fiber at different concentrations: Table 1 Table 1 shows the conversion rate of quinoa decapeptide amyloid fiber at different concentrations. When the concentration of quinoa decapeptide increased from 0.5 mg / mL to 1.0 mg / mL, the conversion rate increased from 96.0% to 96.9%, indicating that more amyloid fiber was formed.
[0042] 2) Effects of different composite ratios on the morphology and microstructure of quinoa decapeptide amyloid fiber aerogel before and after microplastic adsorption Figure 5 The images show the microstructure of different groups of aerogels before and after adsorbing microplastics. The SEM image of sodium alginate aerogel shows a relatively smooth lamellar structure, which is formed during freeze-drying. Ice crystals formed during the freezing process of the polysaccharide gel are removed during the dehydration stage, leaving behind polysaccharide-rich flakes. Quinoa decapeptide amyloid fiber aerogel contains numerous long amyloid fibers. After quinoa decapeptide amyloid fibers are combined with sodium alginate, the amyloid fibers adhere between the lamellar structures, such as... Figure 5 As shown by the green arrows, this creates a more interconnected network structure.
[0043] 3) FTIR analysis of different groups of aerogels Figure 6 The images show the FTIR spectra of quinoa decapeptide, sodium alginate, and aerogels formed by mixing the two in different proportions. In the composite system, due to the high content of quinoa decapeptide, the FTIR spectrum is dominated by quinoa decapeptide. As the proportion of quinoa decapeptide increases, the stretching vibration peak of OH in sodium alginate increases from 3435 cm⁻¹. -1 The peak gradually red-shifts and the peak intensity gradually increases, indicating that hydrogen bonding is enhanced in the composite aerogel.
[0044] Compared with the spectral density of quinoa decapeptide aerogel, the quinoa decapeptide / sodium alginate composite aerogel showed higher spectral density at 1548 cm⁻¹. -1 The peak at 1613 cm⁻¹ (the bending vibration peak of NH in quinoa decapeptide) shows a slight blue shift and the peak intensity is enhanced. Furthermore, compared to sodium alginate aerogel, the characteristic peaks of the asymmetric and symmetric stretched bands of -COO- in the composite aerogel are at 1613 cm⁻¹, respectively. -1 and 1428cm -1The shift of the characteristic peaks of NH and -COO- to higher wavelengths indicates an electrostatic interaction between negatively charged sodium alginate and positively charged quinoa decapeptide.
[0045] Meanwhile, the characteristic peak corresponding to the CH tensile vibration (2961 cm⁻¹) -1 The changes indicate that there is a hydrophobic interaction between quinoa decapeptide and sodium alginate.
[0046] Therefore, the intermolecular forces formed by the quinoa decapeptide / sodium alginate composite aerogel include hydrogen bonds, electrostatic interactions, and hydrophobic interactions.
[0047] 4) Effect of different mass ratios of quinoa decapeptide to sodium alginate on the adsorption of microplastics by aerogel Table 2 shows the effect of the ratio of quinoa decapeptide amyloid fiber to sodium alginate on the adsorption of microplastics by aerogel: Table 2 Table 2 shows the effect of different mass ratios of quinoa decapeptide to sodium alginate on the adsorption of microplastics by aerogels. Water can disrupt the hydrogen bonds and hydrophobic interactions in the quinoa decapeptide amyloid fiber aerogel, causing it to disintegrate upon contact with water, thus preventing the adsorption of microplastics. After adding sodium alginate, the composite aerogel does not disintegrate upon contact with water and retains the ability to adsorb microplastics. The adsorption capacity of PS by the sodium alginate group aerogel is relatively low, at 49.7 ± 7.3 mg / g. With the increase of quinoa decapeptide amyloid fiber content, the adsorption capacity of the quinoa decapeptide amyloid fiber / sodium alginate composite aerogel for PS gradually increases. When the ratio of quinoa decapeptide amyloid fiber to sodium alginate is 3:1, the aerogel exhibits the highest adsorption capacity for PS, reaching 326.2 ± 9.1 mg / g, exceeding that of common cellulose-based or graphene-based aerogels (adsorption capacity approximately 140-250 mg / g).
[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.
Claims
1. A method for preparing quinoa polypeptide aerogel with high adsorption performance, characterized in that: The process includes the following steps: First, the WALTZ algorithm is used to predict and identify the amino acid sequence of easily fibrozable quinoa polypeptides in the quinoa protein fiber solution, and the amino acid sequence of easily fibrozable quinoa polypeptides is obtained. Based on the amino acid sequence of the quinoa polypeptides, the corresponding quinoa polypeptides are synthesized using the Fmoc solid-phase synthesis method. Then, the synthesized quinoa polypeptides are dissolved in water to form a quinoa polypeptide fiber solution. Finally, the quinoa polypeptide fiber solution is mixed with sodium alginate solution to prepare quinoa polypeptide aerogel.
2. The method for preparing quinoa polypeptide aerogel with high adsorption performance according to claim 1, characterized in that: The specific steps are as follows: S1: Prediction and identification of amino acid sequences of easily fibrozed quinoa polypeptides: First, the protein in the quinoa protein fiber solution was precipitated by the trichloroacetic acid precipitation method, and the protein precipitate was reconstituted by adding a reconstitution solution to obtain the sample solution. The reconstitution solution was a mixture of urea and Tris-HCl solution. Secondly, the protein concentration in the sample solution was determined by the dioctanine method. After taking an equal amount of protein to make up the same volume, the sample solution was subjected to a reduction alkylation reaction. Then, Tris-HCl solution was added to the sample solution after the reduction alkylation reaction to dilute the urea concentration in the sample solution. Then, trypsin was added to the sample solution, and the enzyme digestion was performed by shaking overnight at 37°C. The next day, trifluoroacetic acid was added to the sample solution to terminate the enzyme digestion. The supernatant was taken and desalted on a styrene-divinylbenzene-reverse-phase sulfonic acid-based desalting column. After vacuum drying, it was frozen at -20°C. Mass spectrometry data were acquired using a mass spectrometer-liquid chromatography-mass spectrometry system with a mass spectrometry scanning range of 350-1500 m / z. The identified peptides were then combined with the WALTZ algorithm to predict whether there were potentially fibrotic amino acid sequences in the peptides. Finally, the amino acid sequence of the fibrotic quinoa decapeptide was obtained, which is valine-isoleucine-serine-asparagine-isoleucine-tyrosine-glutamine-isoleucine-serine-arginine. S2: Synthesis of Quinoa Decapeptide: The Fmoc solid-phase synthesis method was adopted, starting with Fmoc-Arg(pbf)-WangResin. Through a four-step cycle of "de-wash-attach-wash", the Fmoc-protected amino acids were extended one by one from the C-terminus to the N-terminus and attached to the resin. Finally, the synthesized peptide was cleaved from the resin by TFA, and the side chain protecting groups of the amino acids were removed. The obtained peptide was purified by high performance liquid chromatography, lyophilized, and the sequence and molecular weight were verified by electrospray ionization mass spectrometry. The purity was analyzed by analytical HPLC. S3: Preparation of quinoa polypeptide fiber: Weigh quinoa decapeptide freeze-dried powder and disperse it in water to form a quinoa decapeptide solution. Place it in a water bath and heat it. After heat treatment, immediately cool it in an ice water bath to obtain a polypeptide fiber solution, and store it in a refrigerator at 4°C for later use. S4: Preparation of quinoa polypeptide aerogel: Sodium alginate powder was dispersed in water to form a sodium alginate solution with a final concentration of 20 mg / mL. The solution was magnetically stirred overnight to ensure full hydration. The polypeptide fiber solution and sodium alginate solution were added to a beaker and stirred to form a hydrogel. The hydrogel was soaked in a 10 mg / mL CaCl2 solution for 30 min, and then washed repeatedly with deionized water three times to remove excess calcium ions from the surface. Finally, the hydrogel was freeze-dried for 72 h to form the desired high-adsorption quinoa polypeptide aerogel.
3. The method for preparing high-adsorption-performance quinoa polypeptide aerogel according to claim 2, characterized in that: In step S1, the reconstitution solution is a mixture of 8 mol / L urea and 100 mmol / L Tris-HCl solution with a pH of 8.
5. After the reductive alkylation reaction, 100 mmol / L Tris-HCl solution is added to the sample, and the concentration of urea in the sample needs to be diluted to below 2 mol / L.
4. The method for preparing quinoa polypeptide aerogel with high adsorption performance according to claim 2, characterized in that: In step S1, the mass ratio of enzyme to protein in trypsin is 1:
50.
5. The method for preparing quinoa polypeptide aerogel with high adsorption performance according to claim 2, characterized in that: In step S3, when weighing the quinoa decapeptide freeze-dried powder and dispersing it in water, the concentration of quinoa decapeptide in the water needs to reach 30 mg / mL, and the pH of the quinoa decapeptide solution needs to be adjusted to 7.
0.
6. The method for preparing quinoa polypeptide aerogel with high adsorption performance according to claim 2, characterized in that: In step S3, the temperature of the water bath is 95°C, and the heating time in the water bath is 30 minutes.
7. The method for preparing quinoa polypeptide aerogel with high adsorption performance according to claim 2, characterized in that: In step S4, when adding the polypeptide fiber solution and sodium alginate solution to the beaker, the polypeptide fiber solution and the polypeptide fiber solution and sodium alginate solution are added to the beaker in the order of mass ratio 1:1, 2:1 and 3:1, respectively.