443 results about "Methionine" patented technology

The invention relates to the technical field of biological catalysis, and discloses an M88V mutant enzyme for preparing rebaudioside I. The M88V mutant enzyme is obtained by the following mutations generated by UGT76G1: M88V: methionine of the 88th amino acid sequence of UGT76G1 is mutated into valine. Aiming at the technical bottlenecks of low RI yield and poor selectivity in the existing RA biotransformation process, an efficient solution is provided for the UGT76G1 mutant developed by the invention. The mutant can specifically catalyze conversion from RA to RI, and the conversion rate of a target product is remarkably increased to 65% or above from general less than 7%. The excellent catalytic performance of the catalyst is verified in milliliter-level to upgraded reaction systems, the key problems of conversion efficiency and process amplification are solved, and a foundation is laid for large-scale green manufacturing of a high-added-value product RI.

The invention relates to a betaine phosphate-containing feed additive for improving net energy level and a preparation method and application thereof, and belongs to the technical field of feed additives, the preparation method comprises the following steps: preparing composite betaine phosphate, preparing composite zinc methionine, and mixing; the preparation of the composite betaine phosphate comprises the following steps: preparing a betaine phosphate crude product, preparing a composite silicon dioxide carrier, and crystallizing; the preparation of the compound zinc methionine comprises the following steps: preparing an activated silicon dioxide carrier, adsorbing starch and adsorbing the zinc methionine; in the step of mixing, the compound betaine phosphate and the compound zinc methionine are mixed and then stirred at room temperature, and the betaine phosphate-containing feed additive capable of improving the net energy level is obtained. The feed additive prepared by the invention has a strong effect of improving the net energy level of broiler chickens, is not easy to have the problems of bonding and clustering, and is good in storage resistance.

The invention relates to the technical field of biological catalysis, and discloses an M88A mutant enzyme for preparing rebaudioside I. The enzyme is obtained by the following mutations generated by UGT76G1: M88A: methionine of the 88th amino acid sequence of UGT76G1 is mutated into alanine; the key conversion rate of RI is greatly increased from 7% to 85% (increased by more than 12 times), and the utilization rate and economical efficiency of raw materials are remarkably improved; the method can be perfectly reproduced under any test scale (10mL, 100mL and 5L), the conversion rate is always anchored to be more than 85%, and incomparable stability and amplification potential are shown.

The invention provides pantoea agglomerans and application thereof, and belongs to the technical field of microorganisms, the strain is preserved in China General Microbiological Culture Collection Center (CGMCC), and the preservation number is CGMCC No.36122; the strain has very high selenium tolerance and transformation capacity, and can transform inorganic selenium (such as Se (IV)) with relatively high toxicity into organic selenium (such as selenomethionine and selenocystine) with low toxicity and zero-valent nano-selenium (Se0) in a culture medium containing sodium selenite. The pantoea agglomerans obtained by the invention has the characteristics of selenium-addictive microorganisms, and has potential application value in biotransformation of selenium, microbial synthesis of nano-selenium, and growth promotion and selenium enrichment of crops. The pantoea agglomerans can promote plant growth, a liquid fermentation process developed by the strain is utilized, the highest conversion rate of organic selenium can reach 92.5%, and the synthesis efficiency of nano-selenium reaches 88.3%. And development of organic selenium agricultural products is well facilitated.

The invention discloses a diluent for whole blood lateral immunochromatography detection as well as a preparation method and a detection method thereof, and belongs to the technical field of immunochromatography detection. The diluent solves the technical problems of unsmooth chromatography, background interference, poor stability of detection results and the like caused by red blood cells during direct detection of whole blood samples. The diluent comprises a buffer system, an osmotic pressure regulator glycine, a nonionic surfactant polysorbate, an erythrocyte aggregation inducer polyvinylpyrrolidone, a dynamic viscosity regulator trehalose, a blocking protein, a stabilizer combination L-methionine and L-histidine, and a composite formula of water. Red blood cells are effectively induced to gather and intercept on the sample pad through the synergistic effect of all the components, and meanwhile the stability of the chromatography process and the activity of the detection reagent are maintained. The diluent is mainly used for lateral immunochromatography quantitative detection of markers such as pro-enkephalin, C-reactive protein, cardiac troponin I or N-terminal pro-brain natriuretic peptide in a whole blood sample.

The invention belongs to the technical field of soil organic matter improvers, and discloses a soil organic matter improver based on a compound microbial agent and a preparation method thereof, and the soil organic matter improver comprises the following components: a compound enzyme, a modified chitosan microsphere complex, a modified polyelectrolyte, an inhibitor L-methionine sulfoximine, a substrate, an auxiliary factor and the compound microbial agent. A compound enzyme system is used as a core, soil ammonium ions are circularly and efficiently assimilated through glutamine synthetase / glutamate synthetase, and the soil ammonium ions are converted into organic nitrogen; and energy guarantee is provided by virtue of polyphosphate kinase. The modified chitosan microsphere complex is used for protecting and slowly releasing enzyme and a substrate, and controlled release of the inhibitor L-methionine sulfoximine is realized through the modified polyelectrolyte, so that carbon-nitrogen balance of soil is regulated and controlled. The system has a synergistic effect with a compound microbial agent, the problem of soil organic matter reduction caused by excessive nitrogen application is effectively solved, meanwhile, the crop root biomass is remarkably increased, and the soil organic matter content is increased.

The invention relates to the field of plant molecular biology and forest genetic engineering, and particularly provides a PagRAP2.3 protein point mutant and application thereof in drought resistance of poplar. The mutant PagRAP2.3 MA is obtained by mutating methionine at the first site and cysteine at the second site of a wild type PagRAP2.3 protein into methionine and alanine. The invention further discloses a preparation method of the mutant PagRAP2.3. An expression vector containing the PagRAP2.3 MA gene is constructed, poplar 84K is transformed through an agrobacterium-mediated method, and a transgenic line with stable expression is obtained. Functional verification results show that overexpression of PagRAP2.3 MA can significantly increase the plant height of the poplar and promote plant growth, but the sensitivity to moisture is enhanced under drought stress. The mutant can be used for regulating and controlling the growth and development of forest trees and evaluating the drought resistance, and has a forestry breeding application prospect.

The invention relates to the technical field of biological catalysis, and discloses an M88F mutant enzyme for preparing rebaudioside I. The enzyme is obtained by the following mutations generated by UGT76G1: M88F: methionine of the 88th amino acid sequence of UGT76G1 is mutated into phenylalanine; and the substrate rebaudioside A (RA) can be efficiently and directionally converted into rebaudioside I (RI) with higher value. In an optimized reaction system, the conversion rate stably reaches 40%, and the catalytic efficiency is improved by more than 5-8 times compared with the common reference enzyme. The enzyme preparation has the characteristics of high catalytic activity, mild reaction conditions, simplicity and convenience in operation and the like, shows good stability and reproducibility in laboratory research and large-scale production, and has a wide industrial application prospect.

The invention discloses a method for improving the fermentation performance of clostridium aerovorans and application of the clostridium aerovorans, and according to the method, an effective amount of methionine or a derivative thereof is added into a fermentation culture medium of the clostridium aerovorans to completely replace expensive complex organic nitrogen sources such as yeast extracts. The method successfully solves the three technical bottlenecks of slow biomass accumulation, low ethanol yield and dependence on expensive nitrogen sources in the fermentation process of the clostridium aerovorans by utilizing synthesis gas or CO2 / H2 mixed gas. Experiments prove that methionine or a derivative thereof can synergistically promote growth metabolism of thalli and a synthesis path of a product, so that the gas conversion efficiency of a carbon source is remarkably improved and metabolism is guided to flow to ethanol synthesis while the growth rate and the final biomass of the thalli are improved, and thus the production capacity of alcohols is synchronously enhanced. The method is simple in process and remarkable in effect, and an efficient and economical new strategy is provided for reducing the production cost of biofuel and promoting industrial application of a synthesis gas biorefinery technology.

The invention discloses a compound rumen bypass guanidinoacetic acid additive as well as a preparation method and application thereof, and belongs to the technical field of animal feed additives. The compound rumen bypass guanidinoacetic acid additive provided by the invention is prepared from the following components in parts by mass: 40 to 60 parts of guanidinoacetic acid, 0.1 to 0.5 part of selenium yeast, 5 to 10 parts of nicotinamide, 5 to 12 parts of DL-methionine, 0.01 to 0.05 part of vitamin B12, 1 to 3 parts of compound probiotics, 3 to 5 parts of hydroxypropyl methyl cellulose, 1 to 2 parts of ethyl cellulose, 15 to 25 parts of hydrogenated palm oil and 3 to 5 parts of glyceryl monostearate. The compound probiotics comprise bacillus subtilis and saccharomyces cerevisiae. The compound additive provided by the invention can significantly improve the daily gain of ruminants and reduce the feed-gain ratio, and meanwhile, due to the improvement of the energy utilization efficiency and the enhancement of the antioxidant ability, the immunity of animals is improved, the morbidity is reduced, and the meat quality is improved.

The invention provides an application of synbiotics in preparation of a composition for improving glucagon-like peptide-1 (GLP-1). The composition comprises litchi polyphenol, probiotics and methionine. The probiotics comprise bifidobacterium animalis BCRC910645, bifidobacterium longum BCRC910812, or a combination of the bifidobacterium animalis BCRC910645 and the bifidobacterium longum BCRC910812, so that the content of the glucagon-like peptide-1 is increased.

The invention provides a recombinant O-succinyl-L-homoserine mercaptotransferase mutant, a coding gene thereof, a recombinant vector containing the coding gene of the mutant, a recombinant genetically engineered bacterium obtained by converting the recombinant vector, and application of the recombinant O-succinyl-L-homoserine mercaptotransferase mutant in preparation of L-methionine. The novel recombinant O-succinyl-L-homoserine mercaptotransferase mutant with high activity and high selectivity is used as a catalyst to be applied to catalysis of O-succinyl-L-homoserine for synthesis and preparation of L-methionine, a catalytic reaction system is optimized, the feed ratio and reaction conditions in the reaction are finely regulated and controlled, and the yield of L-methionine is increased. The recombinant O-succinyl-L-homoserine mercaptotransferase mutant has high enzyme activity under the optimal reaction condition, the catalytic efficiency is further improved, the purposes of reducing cost and improving efficiency are achieved, and the method has important significance in promoting industrial application of biological catalysis preparation of L-methionine.

The invention belongs to the field of microbial breeding and fermentation engineering, and particularly relates to a saccharomyces cerevisiae mutagenesis strain with high yield of S-adenosyl-L-methionine as well as a mutagenesis method and application of the saccharomyces cerevisiae mutagenesis strain. Saccharomyces cerevisiae is induced to generate genetic diversity through multiple rounds of ultraviolet mutagenesis, and high-throughput screening is performed in combination with strain color phenotypic difference; and the mutant strain HY2402-Z18 with high yield of S-adenosine-L-methionine and genetic stability is obtained. The SAM yield of the mutagenic strain is increased by 40.1% compared with that of an original strain, the SAM yield reaches 13.44 g / L when the mutagenic strain is fermented for 60 h in a 5 L fermentation tank system, the unit yield reaches 0.156 g / L / OD, and the methionine conversion rate is 75%. After thalli are collected through centrifugation of fermentation liquor, an S-adenosine-L-methionine product with the purity of 98%-100% can be obtained through purification of ion exchange resin, no by-products are accumulated, the yield, the substrate conversion rate and the production efficiency of the S-adenosine-L-methionine can be remarkably improved when the mutagenesis strain is used for fermentation production, and the production cost is reduced. The production cost is effectively reduced, the product purity and quality are improved, and the method is suitable for industrial large-scale production of SAM.

The invention discloses an ergothioneine-producing recombinant engineering bacterium as well as a construction method and application thereof, and belongs to the technical field of gene recombination fermentation. The method comprises the following steps: by taking escherichia coli as a starting bacterium, carrying out recombinant expression on a histidine trimethyl inner salt cysteine sulfoxide synthetase egt1 gene, an L-histidine methyltransferase egtD gene, a histidine trimethyl inner salt cysteine sulfoxide lyase egt2 gene, a methionine adenosine transferase metK gene, an adenylate kinase adK gene and an adenine phosphoribose transferase apt gene; on this basis, supply of precursor substances including histidine, cysteine and methionine is further improved through metabolic transformation, the yield of the finally obtained recombinant engineering bacterium for producing ergothioneine reaches 2.54 g / L after 48 h of shake-flask culture, the yield of a 5L fermentation tank reaches 18 g / L after further enlarged culture, the yield of ergothioneine is guaranteed while energy consumption and cost are reduced, and the method is suitable for industrial production. The method is suitable for practical popularization.

The invention relates to aspartate kinase for relieving feedback inhibition of L-threonine and application of aspartate kinase, and belongs to the field of enzyme engineering and metabolic engineering. The mutant is obtained by carrying out E253K and / or K507E mutation on the basis of wild type aspartate kinase as shown in SEQ ID NO.1, the enzyme activity of the mutant is not obviously changed under the condition that the concentration of L-threonine is 0-12 mmol / L, and the feedback inhibition effect of L-threonine on the mutant is relieved. The method can be widely applied to synthesis of essential amino acids including L-threonine, L-tryptophan, L-isoleucine, L-lysine, L-leucine, L-valine, L-methionine, L-phenylalanine and the like.

An Fc-binding polypeptide with improved alkaline stability comprising a mutant of the Fc-binding domain of Staphylococcus protein A (SpA), said mutant being defined by SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 22, SEQ ID NO 51 or EQ ID NO 52, wherein at least the asparagine or serine residue at a position corresponding to position 11 in SEQ ID NO: 4-7 has been mutated to an amino acid selected from the group consisting of glutamic acid, lysine, tyrosine, threonine, phenylalanine, leucine, isoleucine, tryptophan, methionine, valine, alanine, histidine and arginine.

The invention discloses a pharmaceutical composition for improving liver dysfunction, the pharmaceutical composition comprises a tablet core and a coating film, the tablet core comprises 30-40 parts of mono-ammonium glycyrrhizinate (20-30 parts by weight of glycyrrhizin), 20-30 parts of glycine, 20-30 parts of methionine, 55-65 parts of a filler, 2-10 parts of a disintegrating agent, 1-10 parts of an adhesive and 1-10 parts of a lubricant, and the coating film is a gastric soluble film coating; wherein the filling agent is formed by compounding lactose, microcrystalline cellulose, calcium carbonate, calcium hydrophosphate and mannitol, the mass ratio of the lactose to the microcrystalline cellulose to the calcium carbonate to the calcium hydrophosphate to the mannitol is (1-24): (1-35): (1-25): (1-9): (1-9), and the pharmaceutical composition for improving liver dysfunction has good dissolution and stability.

The application discloses application of a combined inhibitor in associated gold-silver-lead-zinc sulfide ore flotation separation, wherein the combined inhibitor is a combination of zinc sulfate and methionine, and the mass ratio of the two combined is 2:1; the combined inhibitor is used to realize associated gold-silver-low-copper-lead-zinc polymetallic sulfide ore flotation separation in a low-alkali environment, has a good separation effect, high concentrate grade, effectively reduces the zinc content of lead concentrate, improves the gold and silver recovery rate in the lead concentrate, and has important significance for improving the quality and efficiency of associated gold-silver-low-copper-lead-zinc polymetallic sulfide ore flotation separation. In addition, the methionine in the combined inhibitor is a small-molecule organic substance, is non-toxic and non-polluting, and is easy to degrade, thereby avoiding the problems of traditional inhibitors, such as toxicity, environmental unfriendliness and human body unfriendliness. The combined inhibitor has small dosage, stable effect, and good process application prospect.

The invention relates to a protein consisting of an amino acid sequence in which at least one modification selected from the group consisting of the following [1] to [7] is introduced in the amino acid sequence represented by SEQ ID NO: 1: [1] a modification in which the amino acid residue at a position 103 is substituted with a lysine residue, [2] a modification in which the amino acid residue at a position 76 is substituted with a cysteine residue, [3] a modification in which the amino acid residue at a position 144 is substituted with a cysteine residue, [4] a modification in which the amino acid residue at a position 134 is substituted with a glycine residue, [5] a modification in which the amino acid residue at a position 222 is substituted with a methionine residue, [6] a modification in which the amino acid residue at a position 73 is substituted with a glutamine residue, and [7] a modification in which the amino acid residue at a position 203 is substituted with a threonine residue.

The invention belongs to the technical field of enzyme gene engineering, and particularly relates to a methionine gamma-lyase mutant with improved enzyme activity and application thereof. The methionine gamma-lyase mutant CqMGLV160I / V265I with high activity is obtained by taking methionine gamma-lyase (CqMGL) which is derived from Calorama quimayensis and of which cysteine residues at 116 sites are replaced by histidine residues as a parent and carrying out site-specific mutagenesis on amino acid residues at key sites through transformation. The methionine gamma-lyase mutant CqMGLV160I / V265I with high activity can be obtained by using the methionine gamma-lyase mutant CqMGLV160I / V265I as the parent. By adopting the CqMGLV160I / V265I mutant disclosed by the invention, the conversion rate of enzyme catalysis can be improved, allicin is efficiently synthesized, and the mutant is successfully applied to the aspects of food, feed, chemical industry, medicine preparation and the like.

The invention provides a dipeptide capable of rapidly supplementing methionine and application thereof, and belongs to the field of nutritional and functional food. The problems of quickly supplementing methionine and promoting lactation are solved. The preparation method comprises the step of preparing the dipeptide GM of which the C terminal is methionine through solid-phase synthesis. The dipeptide GM can be used for supplementing methionine, and it is verified that compared with EM, KM and MM, the dipeptide GM has the higher methionine absorption rate in cells based on the PepT1 vector. The dipeptide GM can also be used for promoting lactation, and it is verified that the dipeptide GM has a better lactation promoting effect compared with EM, KM and MM.

The present invention relates to a cosmetic composition, advantageously an eco-biological cosmetic composition, comprising: - polyglutamic acid or a salt thereof; and - at least one peptide derivative represented by the general formula (I) in which: - R1 represents a hydrogen atom, an acyl radical or an acyloxy radical; and - R2 represents the side chain of an alpha-amino acid chosen from the group consisting of phenylalanine, glutamic acid, arginine, cysteine, methionine, histidine and tyrosine. The present invention also relates to the use of said cosmetic composition for combating skin redness and / or skin aging; to its use for preventing and / or combating cutaneous vascular hyperproliferation and / or cutaneous inflammation and / or rosacea; and to a method for selecting compounds suitable for preventing and / or combating these pathologies.

This invention discloses a carbetocin injection solution and its preparation process. The raw materials for the carbetocin injection solution include at least carbetocin, methionine, disodium edetate, an antibacterial agent, a pH adjuster, and a solvent. The pH of the carbetocin injection solution is 4.0-4.5. The concentration of carbetocin is 50 μg / ml-80 μg / ml, the concentration of methionine is 10 mg / ml-20 mg / ml, the concentration of disodium edetate is 5 mg / ml-10 mg / ml, and the concentration of the antibacterial agent is 2 mg / ml-3 mg / ml. By controlling the concentrations of carbetocin, methionine, disodium edetate, and the antibacterial agent, and simultaneously adjusting the pH of the injection solution to 4.0-4.5, this invention eliminates the need for nitrogen purging during the preparation process, thereby enabling the prepared carbetocin injection solution to exhibit high antioxidant properties and stability, allowing for long-term storage at room temperature.

The invention relates to the technical field of nestling pigeon breeding, and discloses an artificial irrigation feed for nestling pigeons at the age of 20-28 days in the later growth period and a preparation method of the artificial irrigation feed for the nestling pigeons at the age of 20-28 days. Fully stirring and mixing with monocalcium phosphate, mountain flour, DL-methionine, DL-lysine and sodium chloride according to a formula proportion to obtain a coarse powder mixture; carrying out superfine grinding on the coarse powder mixture, and sieving with a 60-mesh sieve to obtain a superfine powder mixture; and fully stirring and uniformly mixing the superfine powder mixture, the premix and the grease according to the formula proportion to obtain the manual feed for the squeaker in the later growth period. According to the invention, the raw materials and the premix are scientifically proportioned according to the nutritional requirements of the young pigeons, and a reasonable feed preparation method and a reasonable feeding method are formulated, so that the growth requirements of the young pigeons are met, the quality of the meat pigeons is ensured, and the standardization and scale of the meat pigeon industry are further improved.

The invention belongs to the technical field of pet nutrition, and discloses a trace element composite additive for improving the reproductive performance of pets, which comprises the following raw materials: zinc sulfate, sodium selenite, copper sulfate, manganese sulfate, vitamin E acetate, L-lysine hydrochloride, taurine, methionine, selenium yeast and zeolite powder. The zeolite powder is subjected to a specific acid treatment activation process, so that the adsorbability and the stability are improved. The invention also discloses a preparation method of the additive. A three-step mixing process is adopted to ensure the uniformity of the product. The additive is suitable for being added into feed in the breeding period of canine or feline pets, the adding amount of the additive is 0.1-0.5% of the total weight of the feed, and the feeding time is 1 month before breeding and 1 month after breeding. Through scientific proportioning of organic trace elements and inorganic trace elements, in combination with specific amino acids and vitamins, the components have a synergistic effect, so that the pregnancy rate, the litter size and the survival rate of newborn animals of pets are remarkably increased, and meanwhile, the pet feed has good storage stability and use safety.

A method for controlling a chemical process, by preparing methanol, hydrogen sulfide, methyl mercaptan, hydrocyanic acid, acrolein, 3-methylthiopropionaldehyde, 5-(2-methylmercaptoethyl)-hydantoin, methionine, a salt of methionine, and a derivative of methionine. The method includes providing a training set TS1, wherein TS1 is process values PV1 and process values PV2 being correlated to one another, and / or laboratory values LV1 and process values PV2 being correlated to one another. The method includes training a processing unit on the training set TS1 to identify a pattern of correlation between one or more measured process variables and at least one process variable. The method includes developing a calibration function CF1 for a calibrated soft sensor from the identified pattern of correlation and predicting at least one operating parameter for the chemical process as an approximation to LV1 and / or PV1. A system for controlling a chemical process.

The invention provides a preparation method of a recombinant human blood coagulation factor VIII and a product of the recombinant human blood coagulation factor VIII. The preparation method comprises the step of culturing a mammalian cell strain for expressing the recombinant human blood coagulation factor VIII in a serum-free culture medium of a compound containing copper ions and methionine sulfoximine. By adopting the preparation method provided by the invention, the purity of the recombinant human blood coagulation factor VIII product can be further improved on the basis of keeping the high activity and high yield of the recombinant human blood coagulation factor VIII product obtained by culture.

This invention belongs to the field of biomedical technology and relates to the application of YMRFamide short peptide in anti-inflammation. The amino acid sequence of the YMRFamide short peptide is Tyr-Met-Arg-Phe. This invention provides a complete solid-phase synthesis and purification method for this peptide, including using Fmoc-Phe-Wang resin as a starting material, sequentially linking arginine, methionine, and tyrosine, followed by deprotection, resin cleavage, and activated carbon-ethanol crystallization purification steps to finally obtain a high-purity YMRFamide short peptide. The preparation process of this invention is simple, efficient, and reproducible, with significantly improved product stability and solubility. The YMRFamide short peptide exhibits multi-pathway anti-inflammatory potential, is expected to effectively regulate the expression of inflammatory factors, and has high biocompatibility and good safety, providing an important candidate molecule for the development of novel anti-inflammatory drugs.

The present invention relates to peptide conjugates that comprise a plant-derived oligopeptide capable of crossing the blood-brain barrier (BBB) and a therapeutic or diagnostic agent. The BBB-penetrating oligopeptide is an oligopeptide according to Formula I, Asp–R2–Gly–Leu–R5–R6–R7–Leu–Gly–R10–R11–R12, wherein R2 represents Arg, Lys, Cyt, D-Arg or Orn; R5 represents Phe, Arg, Lys, His, Trp, Tyr, D-Tyr, D-Phe, Orn, 4-aminophenylalanine or 3-phenylpropionate; R6 represents Pro, Leu, Glu or Lys; R7 represents Phe or Trp; R10, R11 and R12 each independently represent Lys, Arg or Orn; or an oligopeptide according to Formula II, Glu–R2'–R3'–Gly–R5'–R6'–Glu–R8'–R9'–R10'–Glu–R12'–Leu–Pro–Gly, wherein R2', R3', R8', R10' and R12' each independently represent Lys, Arg or Orn; R5' represents Phe, Ile, Arg, Lys, His, Trp, Tyr, D-Tyr, D-Phe, 4-aminophenylalanine, or 3-phenylpropionate; R6' represents Met, Leu, Ile, Asn, norleucin, D-norleucin, seleno- methionine or D / L-2-hydroxy-(4-methylseleno)butanoic acid; and R9' represents Leu or Ile. The conjugates comprising a BBB-penetrating oligopeptide compound and a therapeutic agent can be used in treatments for diseases of the central nervous system (CNS). Furthermore, conjugates with a BBB-penetrating oligopeptide compound and a diagnostic agent can be used in both in vivo and in vitro diagnostic methods.

This invention relates to a method for the targeted cultivation of live feed to enhance the stress resistance of grouper fry, specifically a method for the targeted cultivation of grouper fry and its live feed. The live feed includes artichoke culture and rotifer culture. The targeted cultivation of the artichoke culture includes the following steps: placing artichokes in seawater, adding *Cryptospira spp.* powder, *Spirulina* powder, arginine, and *Cinnamomum camphora* oil for cultivation to obtain the artichoke culture; the targeted cultivation of the rotifer culture includes the following steps: placing rotifers in seawater, adding *Nyctaginus* pink bacteria. Natrialba pink Rotifer cultures were obtained by cultivating bacterial powder, spirulina powder, methionine, and sunflower oil. This method, through targeted cultivation of live feed, enriches the live feed with corresponding functional components. After feeding it to newly hatched juvenile scorpion, it can significantly improve the stress resistance of the juveniles and increase their survival rate, thus solving the industry pain points of slow development, low survival rate, and poor stress resistance of newly hatched scorpion scorpion.