102results about How to "Small molecular weight" patented technology

The invention discloses a preparation method of a fructus cannabis protein peptide product with effects of resisting fatigue and improving exercise ability, which comprises the following steps: performing preliminary crushing, ultralow-temperature freezing micro-crushing and low-temperature continuous phase-change extraction degreasing on fructus cannabis, performing step-by-step hydrolysis by using polysaccharase and 2.4 L bacterial protease to extract fructus cannabis protein, performing low-temperature salting-out, and performing freeze-drying to obtain the fructus cannabis protein peptide product with the effects of resisting fatigue and improving exercise ability. The fructus cannabis protein peptide powder is prepared through low-temperature ultrasonic dissolution promotion, high-pressure micro-jet homogenization, compound enzyme C hydrolysis, 1% pepsase, high-temperature enzyme deactivation, chlorophyll removal through counter-current extraction, hydrogen peroxide decoloration, ultralow-temperature instantaneous concentration, low-temperature vacuum belt type drying and low-temperature ultrahigh-pressure sterilization. The fructus cannabis protein peptide prepared by the invention has the following remarkable effects: 1, the exercise ability is remarkably improved, the accumulation of lactic acid and urea nitrogen is reduced, the exhaustion time is prolonged, and the physical and mental fatigue is relieved; 2, the content of hepatic glycogen and muscle glycogen is obviously increased, the energy reserve of the body is increased, the explosive power and the reactivity are improved, and the athletic performance is improved; and 3, the antioxidant level of the body is improved, and fatigue and immune recovery after exercise are promoted.

The application discloses a use of a quaternary deep eutectic solvent of zinc chloride tetrahydrate and phosphoric acid, the quaternary deep eutectic solvent of zinc chloride tetrahydrate and phosphoric acid is composed of zinc chloride as a hydrogen bond acceptor, phosphoric acid as a hydrogen bond donor and water as a solvation regulator; the quaternary deep eutectic solvent of zinc chloride tetrahydrate and phosphoric acid is used for depolymerizing lignin to prepare small molecule lignin; the quaternary deep eutectic solvent of zinc chloride tetrahydrate and phosphoric acid of the application utilizes Lewis acid and Bronsted acid to synergistically catalyze, efficiently depolymerizes lignin at 60-105 DEG C, and targets to cut off aryl ether bonds; the quaternary deep eutectic solvent has low viscosity and good fluidity, meanwhile, water molecules play a nucleophilic quenching role, and inhibit secondary condensation reaction; after the depolymerization reaction is completed, high-activity small molecule lignin can be obtained through simple water addition and precipitation; the solvent can be recycled; washing liquid can be closed-loop circulated, zero wastewater discharge is realized; the obtained product has a significantly reduced weight average molecular weight and abundant free phenolic hydroxyl groups, and can replace phenol to directly serve as a raw material to synthesize phenol-formaldehyde resin adhesive and the like.

This invention belongs to the field of functional substance research, specifically relating to the use of casein hydrolyzed peptide compositions in improving aging, and more specifically to their use in the preparation of products for improving aging. The casein hydrolyzed peptide compositions are obtained by enzymatically hydrolyzing casein solution using serine protease and flavor protease. Furthermore, in the casein hydrolyzed peptide compositions, the relative strength of total functional peptides is above 25%, the relative strength of casein phosphopeptides is above 9%, and the relative strength of functional peptides other than casein phosphopeptides is above 11%. This casein hydrolyzed peptide composition can effectively alleviate oxidative stress caused by aging, inhibit chronic low-grade inflammation, reduce aging-related damage to vital organs such as the liver and brain, improve the body's immune function, and improve the external phenotype of aging, thereby comprehensively exerting an anti-aging effect.

This invention belongs to the field of photocrosslinking probe technology, specifically relating to a GUSB photocrosslinking probe, its preparation method, and its application. The GUSB photocrosslinking probe has the general chemical formula C0. 13 H 18 N2O6-R, wherein R is any one of the oxalic group elements or peptide bonds. The R group covalently connects the glucuronic acid recognition core and the photosensitive unit in the GUSB photocrosslinking probe, and the R group contains no more than 4 atoms, resulting in a small size and low steric hindrance. The GUSB photocrosslinking probe provided by this invention uses glucuronic acid as the recognition core, combined with a small-volume diazacyclopropane photosensitive unit and a terminal alkyne group, to achieve µM-level in-situ covalent capture of active GUSB in complex systems such as cells or tissues. The probe of this invention significantly improves positioning accuracy, sensitivity, data availability, quantification, and enrichment, while also possessing advantages such as modular synthesis, mild conditions, and strong system compatibility, effectively addressing the technical shortcomings of existing technologies that struggle to accurately obtain GUSB activity in situ under low-dose conditions.

The present invention provides a high-protein bio-fermented aquatic feed and a preparation method thereof. The aquatic feed comprises the following raw materials in parts by weight: 20-30 parts of imported fish meal, 10-15 parts of compound minerals, 5-10 parts of bioactive peptides, 5-10 parts of lysine, 5-10 parts of compound trace elements, 3-8 parts of compound vitamins, 3-6 parts of herbal extracts, 2-5 parts of compound probiotics, 2-4 parts of immune polysaccharides, and 1-3 parts of compound enzymes; the herbal extracts are prepared by fermenting astragalus membranaceus, isatis root, liquorice root, calotropis gigantea, ventilago leiocarpa benth, clove, rhizoma chuanxiong, and galangal officinale. By organically integrating imported fish meal, astaxanthin-peptide chelate, herbal extracts, compound immune polysaccharides, compound probiotics and various nutrients, the present invention realizes the synergistic effect of "promoting feeding - enhancing digestion - strengthening liver and gall - enhancing immunity - resisting stress - inhibiting bacteria - stabilizing water quality", significantly improves the growth rate, survival rate and comprehensive breeding benefit of crustacean aquatic animals, and has good economic value and application prospect.

This invention discloses a method and system for treating landfill leachate stock, belonging to the field of wastewater treatment technology. The method includes the following steps: first, adding an appropriate amount of acid to the landfill leachate and stirring until homogeneous to obtain an acidic solution with a pH value below 1.5; then, adding silicate cement to the acidic solution in one go or in small amounts multiple times, mixing thoroughly, and allowing it to settle until solids precipitate before discharging the liquid to the external environment or transporting it to the next process. The total amount of silicate cement added is 6%-10% of the mass of the acidic solution. This method can simultaneously treat TP, TN, and NH3 in landfill leachate. 3 Removal of -N and COD, TP, TN, NH 3 The removal rate of nitrogen (-N) can reach over 75%, and the COD removal rate can reach over 30%. The levels of recalcitrant organic macromolecules and benzene ring compounds are significantly reduced. The organic matter in the water sample is reduced, and the molecular structures are simpler and smaller, which is beneficial for biological decomposition and utilization. The system has a simple structure, is easy to use, and significantly reduces water treatment costs.

The invention relates to the field of biological medicine, in particular to a cyclic peptide capable of being specifically combined with tiralizumab, a cyclic peptide derivative and application of the cyclic peptide derivative in recognition and combination of tiralizumab. The invention provides a novel teralizumab specific binding cyclic peptide which can specifically recognize and bind to teralizumab. The polypeptide can be chemically synthesized and labeled with various reporter molecules, has small batch difference, small molecular weight and high stability, and can be stored and used for a long time. According to the present invention, after the teralizumab specific binding cyclic peptide modifies different reporter molecules, the biosensor for detecting the blood concentration of the teralizumab can be constructed;

The application relates to the field of biological medicine, and particularly discloses application of a polypeptide in preparation of a specific targeting molecular probe for tumors with DLL3 overexpression. The application finds that a molecular probe prepared from a polypeptide shown in SEQ ID No. 4 can effectively target tumor tissues with DLL3 overexpression, thereby providing application of a polypeptide or a dimer or a multimer thereof in preparation of a specific targeting molecular probe for tumors with DLL3 overexpression, wherein the amino acid sequence of the polypeptide is shown in SEQ ID No. 4. The molecular probe of the application has high imaging precision, good affinity with DLL3, can realize early diagnosis and imaging of tumor tissues, and can also be used for preoperative and intraoperative image navigation, thereby improving the operation accuracy.

The application discloses a polypeptide ligand for brain glioma diagnosis and preparation and application of a radioactive molecular probe. The polypeptide targeting a TREM2 protein has the amino acid sequence as shown in the following: HLRKLRKR. The targeted polypeptide designed by the application has the characteristics of small molecular weight, strong blood brain barrier penetration and strong TREM2 protein binding capacity. The radioactive nuclide labeled molecular probe prepared by the application has the characteristics of strong targeting and easy observation as a brain glioma imaging drug, and is convenient for clinical application. The application improves the diagnosis effect of brain glioma and provides a new idea for early discovery and early treatment of brain glioma.

The application belongs to the technical field of biological medicine, and particularly relates to a polypeptide degradation agent for targeted degradation of CD26 and a preparation method and application thereof. The polypeptide degradation agent is obtained after coupling of a tetrapeptide and lenalidomide. The amino acid sequence of the tetrapeptide is any one of SEQ ID NO. 1 and SEQ ID NO. 2. The polypeptide degradation agent can specifically target and degrade DPP4, i.e. CD26, but cannot degrade DPP4 isozymes such as DPP7, DPP8 and DPP9, and thus has high selectivity. In addition, the polypeptide degradation agent has small molecular weight, one end is a natural short peptide, has good tissue compatibility, can quickly degrade target proteins in 6 hours, and thus has good tissue permeability.

This invention discloses a micropeptide, its encoding nucleic acid, and its application in regulating inflammatory activation of microglia. The amino acid sequence of the micropeptide is shown in SEQ ID NO:3. Simultaneously, this invention discloses the nucleic acid encoding the micropeptide, which contains either the nucleotide sequence shown in SEQ ID NO:1 or the nucleotide sequence shown in SEQ ID NO:2, wherein SEQ ID NO:2 is a small open reading frame located within the sequence of SEQ ID NO:1. This invention validated the translational expression of the micropeptide in microglia by constructing an EGFP reporter gene fusion vector and a SUMO tag fusion expression vector. Functional experiments showed that under oxygen-glucose deprivation / reperfusion injury conditions, the micropeptide significantly inhibited inflammatory activation of microglia. This invention provides a new potential target and candidate drug for the treatment of neuroinflammatory diseases such as stroke.

This invention belongs to the field of molecular biology and medical detection technology, and discloses a bladder cancer-specific nucleic acid aptamer, nucleic acid aptamer derivatives, and their applications. The nucleotide sequences of the nucleic acid aptamer are shown in SEQ ID NO: 1, 2, and 3. This invention screened three monoclonal nucleic acid aptamer DNA chains from bladder cancer tissue samples using the exponential enrichment systematic evolution (SELEX) technique and identified two target proteins that bind to these three nucleic acid aptamers. The nucleic acid aptamers specifically target the target proteins CAPRIN1 and FXR1 on the surface of bladder tumor cells. The nucleic acid aptamers obtained by this invention have advantages such as high affinity and specificity, no immunogenicity, simple chemical synthesis, stability, and ease of storage and labeling, providing a new molecular tool for the early diagnosis and targeted therapy of bladder cancer.

This invention discloses an environmentally friendly plasticizer using modified lignin as a carrier, a rubber composition, and a method for preparing the same, relating to the field of rubber processing technology. The environmentally friendly plasticizer using modified lignin as a carrier, by weight, comprises the following components: 50 parts modified lignin, 25 parts plasticizing active ingredient, 8 parts dispersant, 5 parts anti-aging agent, and 3 parts stabilizer. The modified lignin is a lignin oligomer containing ester, acetyl, and ether cross-linked structures, with a weight-average molecular weight of 800-1200 Da, a dispersion coefficient ≤1.5, and a carboxyl content ≤0.2 mmol / g. This invention successfully overcomes the technical defects of existing plasticizer carriers, such as high toxicity, difficulty in degradation, and poor compatibility with polymer matrices, providing an environmentally friendly plasticizer using modified lignin as a carrier. This technical solution achieves the dual goals of high-value utilization of lignin and greening of the plasticizer product.

The invention discloses brown cattle bone marrow collagen polypeptide with an immunoregulation effect as well as a preparation method and application of the brown cattle bone marrow collagen polypeptide, and belongs to the technical field of animal-derived food processing. The preparation method comprises the following steps: pretreating brown cattle bone marrow; the method comprises the following steps: dissolving pretreated brown cattle bone marrow in water, firstly adding alkaline protease to carry out enzymolysis, then simultaneously adding collagenase U and basophilic protease into a system, carrying out coupled enzymolysis under the protection of nitrogen, then cooling the system to 0-4 DEG C, regulating the pH value to 3-4, then carrying out autolysis for 10-30 minutes, and finally carrying out enzyme deactivation; centrifuging an enzyme deactivation product, taking supernatant, adjusting the pH value to be neutral, concentrating, dialyzing and freeze-drying to obtain crude collagen peptide; and carrying out primary purification and secondary refining on the crude collagen peptide to obtain the collagen peptide. The preparation process is simple, the molecular weight of the prepared polypeptide is 366-1514 Da, and the polypeptide has immunoregulation and antioxidant activity, can be used for preparing food, health care products or medicines for improving immunity and resisting oxidation, and realizes high-value utilization of livestock and poultry byproducts.

This invention belongs to the field of synthetic rubber preparation technology, specifically relating to low Mooney viscosity atactic 1,2-polybutadiene, its preparation method, and its applications. The preparation method of the low Mooney viscosity atactic 1,2-polybutadiene includes the following steps: under a protective gas atmosphere, adding a phosphate ester compound to a molybdenum compound, aging and cooling, then adding toluene to obtain a main catalyst; placing a trialkylaluminum alkane solution in an ice-water bath, adding aryloxy ligands dropwise to the container, and reacting in an ice-water bath to obtain a co-catalyst; dissolving butadiene in an alkane solution, adding the co-catalyst, main catalyst, activator, and molecular weight regulator respectively, and carrying out a polymerization reaction to obtain low Mooney viscosity atactic 1,2-polybutadiene. This invention provides a method for preparing low Mooney viscosity atactic 1,2-polybutadiene with high conversion rate; the obtained 1,2-PB has a low Mooney value and a high 1,2-structure content; it can be applied to rubber additives and damping materials to improve their performance.

The application provides a CRISPR-Cas protein for epigenetic editing and application thereof, and belongs to the technical field of nucleic acid editing.The application provides a PmCas12m protein for epigenetic editing, and the amino acid sequence is shown as SEQ ID NO:1.Meanwhile, the application obtains a group of PmCas12m protein mutants for epigenetic editing based on structure optimization, and the high-efficiency epigenetic editing capability of the PmCas12m protein is improved.The CRISPR-Cas12m system based on the PmCas12m protein or the mutant thereof can efficiently realize epigenetic regulation of prokaryotes and eukaryotes, and effectively realize the purpose of antiviruses, and provides a new strategy for virus treatment.

The application discloses a method for preparing modified carrageenan by using a slurry method and application thereof. The method comprises the following steps: uniformly mixing potassium salt, deionized water, an oxidant and carrageenan to obtain a slurry, preparing modified carrageenan by using the slurry oxidation method, and improving the stability of the modified carrageenan in the oxidation degradation reaction through the electrostatic action between potassium ions and sulfate radicals in the carrageenan, so that the content of the sulfate radicals in the modified carrageenan is improved. The method uses a single hydrogen peroxide oxidant, has simple and efficient preparation, low solvent consumption, is green and environment-friendly, and has the dual advantages of low molecular weight and high sulfate radical content of the prepared modified carrageenan, and has a wide application prospect in the field of anticoagulation.

The invention relates to the field of cosmetics, in particular to a cosmetic composition containing sturgeon polypeptide and a preparation method and application of the cosmetic composition. According to the cosmetic composition containing the sturgeon polypeptide, the cosmetic composition contains the sturgeon polypeptide, and the sturgeon polypeptide is derived from sturgeon eggs. The sturgeon polypeptide from sturgeon roes is selected as an active ingredient of the cosmetic, and the polypeptide is small in molecular weight, good in biocompatibility, capable of participating in skin cell metabolism regulation and beneficial to promoting synthesis of COL-I and ELN. Compared with an existing cosmetic mainly containing common protein or non-specific polypeptide, the composition has more obvious efficacy advantages in the aspect of improving skin fine wrinkles and wrinkles.

The application belongs to the technical field of biotechnology, and particularly relates to a pharmaceutical composition containing exosomes and application thereof. The pharmaceutical composition containing exosomes comprises stem cell exosomes, recombinant IGFBP7 protein and baeckea fruitin B; the amino acid sequence of the recombinant IGFBP7 protein is shown as SEQ ID NO:1. Test results show that the combination of umbilical cord mesenchymal stem cell exosomes, baeckea fruitin B and recombinant IGFBP7 protein can stimulate hair follicle stem cells, prolong the initial stage of hair growth of hair follicles, and thus effectively improve the hair loss of patients.

The present application relates to the technical field of gene editing, in particular to a Slug mutant protein, a CRISPR / Cas9 gene editing system comprising the same, and application thereof. More particularly, the SlugCas9 mutant protein of the present application forms a complex with a single-stranded guide RNA, which has a simpler PAM than the wild-type SlugCas9 complex, a larger targeting range, can accurately locate a target DNA sequence and produce a cut, cause double-strand breakage damage to the target sequence, has high specificity, can reduce off-target rate of gene editing in cells or in vitro, and has a wide application prospect.

On one hand, the invention discloses an anti-FOLR1 single-domain antibody VHH-F01, the amino acid sequence of the VHH-F01 is as shown in SEQ ID NO: 2, and the gene sequence of the VHH-F01 is as shown in SEQ ID NO: 1. The invention also discloses an umbilical cord mesenchymal stem cell preparation, which is characterized in that the preparation introduces the single-domain antibody VHH-F01 targeting the human FOLR1 and the gene of the human Bcl-2 anti-apoptotic protein into umbilical cord mesenchymal stem cells together through a lentiviral vector to obtain a stable and high-expression cell population; vHH-F01 expressed on the membrane surface of the preparation can specifically recognize ovarian cancer cells highly expressed by FOLR1 and can be combined with the ovarian cancer cells highly expressed by FOLR1 with high affinity, and meanwhile, the survival ability of stem cells in a tumor microenvironment can be remarkably enhanced by intracellular highly expressed Bcl-2 protein. In-vitro and animal experiments show that the preparation has excellent targeting homing efficiency and remarkable tumor inhibition effect on ovarian cancer tissues, can effectively prolong the lifetime of model animals, and provides a novel efficient targeting treatment tool for cell therapy of ovarian cancer.

The invention relates to the technical field of immunity, in particular to a nano antibody specifically combined with CD276 and application of the nano antibody. The preparation method comprises the following steps: immunizing alpaca by adopting human CD276 antigen protein to obtain peripheral blood PBMC (peripheral blood mononuclear cell), then calling a nano antibody gene, establishing a phage library, finally obtaining an antibody sequence with relatively high antigen affinity respectively through a single B cell antibody screening technology and a phage library screening technology, and then applying the found antibody sequence to CAR-T to obtain a CAR-T antibody sequence with relatively high antigen affinity. Animal in-vivo and in-vitro drug effects show that the obtained antibody sequence is suitable for various solid tumor indications and has a remarkable anti-tumor effect on lung cancer, colorectal cancer and pancreatic cancer. The antibody sequence can be applied to development of antibody drugs, cell therapy drugs, ADC drugs and the like.

The invention discloses a novel oligopeptide PSP for angiogenesis and vascularized bone regeneration. The tripeptide innovatively screened by the invention is short in amino acid sequence, small in molecular weight, high in bioavailability, low in synthesis cost and easy to transport, modify and recombine. The tripeptide provided by the invention can significantly promote vascularized bone regeneration and improve skull defect repair. Good application prospects are realized.

The application discloses a bovine type I alpha interferon-ferritin fusion protein, a mutant thereof, and a preparation method and application thereof. The bovine type I alpha interferon is fused with a ferritin subunit, the self-assembly characteristics of the ferritin are utilized, the interferon molecules are highly repeated and orderly displayed on the surface of the ferritin nanocage, and the expression level, structural stability and antiviral activity of the interferon are significantly improved. The fusion protein is further subjected to rational design mutation at a unit point or multiple points, and a mutant with significantly improved antiviral activity and stability is obtained. The fusion protein or the mutant thereof is expressed by using a silkworm or insect cell eukaryotic expression system, the expression system is safe in operation, simple in procedure, low in cost, and extremely beneficial to large-scale industrial production, and the prepared fusion protein or mutant nanometer particle has application prospects in the preparation of medicines or reagents for preventing or treating bovine viral diseases.

The present application relates to a polypeptide for repairing skin injury or mucosa injury, which has obvious effects of reducing pathological development of acute and chronic gastrointestinal diseases, promoting repair of skin or mucosa injury, treating tumors and the like, and use of the polypeptide for repairing skin injury or mucosa injury. Specifically, the present application relates to a polypeptide capable of binding to FGFR1 receptor, which plays a role in inhibiting or promoting cell proliferation, vascular proliferation, collagen formation and the like by blocking or activating FGF / FGFR1 signal transmission.

This invention relates to the field of ginseng extract technology, specifically to a composition containing ginseng extract and its preparation method. The provided composition containing ginseng extract comprises the following substances in parts by weight: 5-30 parts of a ginseng peptide composition with a molecular weight less than 3000 Da; 1-15 parts of a saponin composition composed of rare ginsenosides Rg3, Rg5, and Rh2; 3-10 parts of a ginseng polysaccharide-selenium nanocrystal composition; 1-5 parts of *Lactobacillus plantarum* P-8 lyophilized powder; 0.5-3 parts of sodium tanshinone; 3-20 parts of a prebiotic composition; and 0.1-5 parts of a vitamin composition. A method for preparing the aforementioned ginseng extract composition is also provided. The prepared ginseng extract composition exhibits excellent properties and has good application prospects.

The application belongs to the technical field of biological medicine, and particularly relates to an anti-CD22 nanobody and a preparation method and application thereof. The anti-CD22 nanobody comprises a framework region and a complementarity determining region, wherein the complementarity determining region comprises CDR1 (SEQ ID NO: 1), CDR2 (SEQ ID NO: 2) and CDR3 (SEQ ID NO: 3). The preparation method comprises the following steps: immunizing a llama with a Human CD22 / His protein, extracting RNA from PBMC cells and reverse transcribing the RNA into cDNA, constructing a phage display library, obtaining a positive clone through CD22 antigen protein panning after sequencing analysis, and expressing the antibody through a mammalian cell expression system. The application adopts an optimized phage display technology, has a short screening cycle, and the obtained nanobody has a small molecular weight, a stable structure and high affinity to CD22. The antibody can be efficiently expressed through a mammalian cell, and retains natural modification activity.

The application relates to the technical field of wood decoration materials, and particularly discloses a wood surface composite structural color protective layer and a preparation method. The application first self-assembles and constructs a structural color layer on the wood surface; then applies PVB ethanol solution, and forms a PVB layer which internally strengthens the structural color layer in a dot-shaped bonding mode after drying; and finally coats UV paint and forms an outer protective layer through ultraviolet light curing. The PVB layer of the application effectively strengthens the cohesive force and the adhesion to the substrate without destroying the order of the structural color layer; the UV paint layer is firmly combined with the PVB layer through possible chemical bonding, and excellent wear resistance and scratch resistance are provided. The two are synergistic, solve the technical problem that the adhesion of the traditional wood surface structural color layer is poor and the structural color layer is easily damaged, and the prepared color protective layer is bright in color and has a wide application prospect.

The application discloses a transcritical CO2 air source heat pump system and a control method thereof. The transcritical CO2 air source heat pump system comprises a carbon dioxide compressor, a gas cooler, an electronic expansion valve, an outdoor fan, a cold storage device, a heat storage water tank, a high-temperature heat accumulator, a low-temperature heat accumulator and a floor buried pipe heat exchanger. The gas cooler comprises a first working medium pipeline and a first heat exchange pipeline for realizing heat exchange. The cold storage device comprises a second working medium pipeline and a second heat exchange pipeline for realizing heat exchange. The heat storage water tank comprises a hot end heat exchange pipeline and a cold end heat exchange pipeline for realizing heat exchange. The transcritical CO2 air source heat pump system can be controlled to be in various working conditions, such as single hot water production, refrigeration and hot water production, single heating, heating and hot water production and the like, by controlling the opening and closing of each component and valve, and is integrated and multipurpose to adapt to different requirements.

This invention relates to the field of biomedical technology, and more particularly to a PD-L1-targeting polypeptide, its conjugate, and its applications. The polypeptide possesses the amino acid sequence shown in SEQ ID NO.1 or SEQ ID NO.2. This invention de novo designs a high-affinity PD-L1-targeting specific polypeptide. This polypeptide achieves extremely high affinity with the extracellular domain of the PD-L1 protein through its unique spatial conformation, exhibiting excellent targeting and recognition capabilities. The polypeptide provided by this invention can be conjugated with various modified molecules, such as radionuclides, and the constructed molecular imaging probe exhibits excellent tumor tissue targeting and enrichment capabilities, superior biocompatibility, and clear imaging contrast, enabling specific recognition of PD-L1-positive tumor lesions. It can be applied to clinical scenarios such as early precision diagnosis of tumors, screening of patients for immunotherapy, real-time monitoring of efficacy, and prognostic assessment, possessing significant translational medical value and broad application prospects.