CN-122011373-A - Synthesis and application of polycaprolactone-glutamic acid block polymer

Abstract

The invention relates to synthesis and application of polycaprolactone-glutamic acid block polymer, and provides a polypeptide vesicle synthesized by PCL-NH2 initiated BLG polymerization through a self-designed catalytic system. Experiments prove that the constructed vesicles have double functions, can obviously promote cell proliferation in the fermentation process of cassava clear liquid, and can synchronously improve the sugar consumption rate. The system breaks through the traditional limitation of the application fields of biomedicine and biofuel, shows an example of actively regulating and controlling the biosynthesis of microorganisms by polypeptide vesicles for the first time, and builds a sustainable research platform for polypeptide nano particles and biorefinery.

Inventors

• BAI YUGANG
• YAO YUAN

Assignees

• 湖南大学

Dates

Publication Date

20260512

Application Date

20251218

Priority Date

20251201

Claims (6)

1. 1. A method for synthesizing an NCA polymerization catalyst, comprising the steps of: Step 1, synthesizing SiO 2 nanosphere particles; Preparing a solution A, namely uniformly mixing ammonia water, ethanol and deionized water; Preparing a solution B, namely mixing triethoxysilane with ethanol; Rapidly pouring the solution B into the solution A at one time while vigorously stirring the solution A, stirring at room temperature, centrifugally collecting a solid product, washing, centrifugally treating, washing with ethanol for three times, and finally drying in a vacuum oven to obtain SiO 2 nanosphere particles; Step 2, amination (SiO 2 -NH 2 ) modification of SiO 2 nanosphere particles; Dispersing the obtained SiO 2 nanosphere particles in toluene solution, then adding APTES, heating the mixture for reaction, collecting a solid product through centrifugation after the reaction is finished, washing the solid product with ethanol for three times, and finally drying the solid product in a vacuum oven; Step 3, initiating polymerization by SiO 2 -NH 2 to generate a polymerization catalyst (SiO 2 @PBLG); Dispersing synthetic SiO 2 -NH 2 in dichloromethane, adding BLG monomer, directly and rapidly initiating NCA polymerization reaction by SiO 2 -NH 2 to generate a silicon dioxide polypeptide compound, drying the compound under vacuum, grinding dried solid particles, adding acetic anhydride, reacting excessive surface amino groups, washing the obtained solid with methanol, and finally drying in a vacuum drying box to obtain the silicon dioxide polypeptide catalyst.
2. 2. The synthesis according to claim 1, wherein the synthesized SiO 2 -NH 2 is dispersed in methylene chloride and BLG monomer is added in a mass ratio of 1:1.
3. 3. An NCA polymerization catalyst (SiO 2 @ PBLG) synthesized by the synthetic method of any one of claims 1-2.
4. 4. A method for synthesizing a block polymer additive of polycaprolactone-glutamic acid using the NCA polymerization catalyst of claim 3, comprising the steps of: Dissolving BLG-NCA in dichloromethane, pre-dispersing SiO 2 @PBLG catalyst in dichloromethane by ultrasonic treatment, adding the catalyst into the dichloromethane mixture, stirring, quickly adding PCL-NH 2 initiator into the reaction solution, stirring at room temperature, monitoring the conversion rate of NCA by utilizing Fourier transform infrared spectroscopy (FT-IR), centrifuging the reaction mixture after the reaction is finished, and adding the supernatant into methanol to precipitate a polypeptide product (PCL@PBLG); Step two, the obtained PCL@PBLG product is added to HBr-CH 3 COOH solution, stirred at room temperature overnight, then concentrated in vacuo, then the crude product is dried with an oil pump to remove the excess acid, finally the residue is added to DMF/H 2 O mixed solution in a ratio of 1:3 (volume ratio), and purified by dialysis treatment in 30% NaHCO 3 solution and pure water, and the dialysate is treated by freeze drying to obtain the deprotected product.
5. 5. A method of promoting vesicle proliferation using the additive of claim 4.
6. 6. The method of claim 5, wherein vesicle proliferation is promoted by intracellular targeting of mitochondrial organelles and lowering mitochondrial ROS levels.

Description

Synthesis and application of polycaprolactone-glutamic acid block polymer Technical Field The invention relates to the technical field of yeast fermentation and application thereof, in particular to application of polypeptide polymer synthesis and development with promotion effect on yeast cell proliferation in the fermentation process. Background Saccharomyces cerevisiae (Saccharomyces cerevisiae) is the most critical industrial microorganism worldwide, not only the most prominent ethanol producer in the alcoholic beverage and biofuel fields, but also more than 80% of renewable fuel supplies worldwide provide support. The high-efficiency fermentation capability of the fermentation material forms the basis of the industries of beer, wine, distilled liquor and bioethanol and becomes an indispensable core element in multi-national economy and energy strategy. During fermentation, yeast cells typically require nitrogen sources and minerals such as magnesium/zinc as essential nutrients to maintain growth and metabolic activity. However, continuous fermentation often results in nutrient depletion, leading to metabolic starvation, and thus fermentation stagnation or reduced efficiency. Conventional optimization strategies typically rely on supplementation of nitrogen sources (e.g., urea) or exogenous magnesium/zinc ions to boost enzyme activity, but such methods have significant drawbacks while improving fermentation performance, not only due to increased risk of cytotoxicity by using poorly biocompatible additives (especially in food grade applications), but also due to the need for continuous exogenous supplementation, which greatly increases the process complexity and cost burden of industrial-grade production. In contrast, the introduction of biocompatible additives at the initial stages of fermentation, whereby activation of cell viability by modulating organelle function is considered to be a more efficient optimization pathway, may enable an increase in overall process fermentation efficiency. The prior researches find that certain Mitochondrial Targeting Peptides (MTPs) can enhance mitochondrial activity so as to regulate and control the cell life process, but the peptide substances require complex synthesis and purification steps due to special structural motifs, and seriously restrict the industrial application of the peptide substances. Disclosure of Invention The invention relates to a polypeptide macromolecule which has the capability of promoting the proliferation of yeast cells and improving the fermentation efficiency. The core of the invention is that polycaprolactone-glutamic acid segmented copolymer is conveniently and efficiently synthesized by an independently designed NCA polymerization catalyst, and the polypeptide macromolecule is found to be used as a biocompatible additive to effectively promote cell proliferation, thereby effectively improving the yeast fermentation efficiency. The core of the invention is that the adopted self-designed catalyst is used for NCA polymerization initiation of polycaprolactone-NH 2, the mode can overcome the defect that the traditional polymerization mode has severe requirements on polymerization conditions, the rapid polymerization is realized under the condition of water and oxygen, the polymer formed by polymerization forms a polypeptide vesicle after the end deprotection, and the vesicle has good biocompatibility and can directly target mitochondrial organelles in cells. A method for synthesizing NCA polymerization catalyst comprises the following steps of 1, synthesizing SiO 2 nanosphere particles, preparing solution A by uniformly mixing ammonia water, ethanol and deionized water, preparing solution B by mixing triethoxysilane and ethanol; The preparation method comprises the steps of rapidly pouring a solution A into the solution A at one time while stirring the solution A vigorously, stirring the solution B at room temperature, centrifugally collecting a solid product, washing the solid product, centrifugally treating the solid product, washing the solid product with ethanol for three times, finally drying the solid product in a vacuum oven to obtain SiO 2 nanosphere particles, performing amination (SiO 2-NH2) modification on the SiO 2 nanosphere particles in the step 2, dispersing the obtained SiO 2 nanosphere particles in a toluene solution, adding APTES, heating the mixture for reaction, centrifugally collecting the solid product after the reaction, washing the solid product with ethanol for three times, finally drying the solid product in the vacuum oven, performing polymerization by using SiO 2-NH2 to obtain a polymerization catalyst (SiO 2 @PBLG), dispersing the synthesized SiO 2-NH2 in dichloromethane, adding a BLG monomer, performing direct and rapid NCA polymerization reaction by using the SiO 2-NH2 to obtain a silica polypeptide compound, drying the compound under the vacuum condition, grinding the dried solid particles, adding acetic anhy