32 results about "Diaminopimelic acid" patented technology

The invention relates to an antibiotic streptomyces, fermentation product of which can inhibit broad spectrum fungus and protozoan, and field experiment can control crop fungus plant disease and root-knot nematode. The antibiotic streptomyces has good effect, no pollution nuisance and no residue. The antifungal agent has extremely low hazardness for the people and good performance and development prospect for medical and agricultural use. The invention is named as SIM001 antibiotic streptomyces which is Streptomyces antibioticus subspecies xi an, and is preserved as patent in the depositary institution appointed by patent office of state intellectual property office; the preservation data is April 14th, 2005, the name of the depositary institution is CGMCC, and the number of preservation is CGMCC No.1349. The whole cell hydrolysate of the antibiotic streptomyces contains L, L-DAP (Diaminopimelic acid) and no characteristic glucide; the cytoderm belongs to I type and glucide type C; one of the main antibacterial materials is polyene macrocyclic ketolide which belongs to the broad spectrum antifungal substance.

The invention provides recombinant escherichia coli and application to synthesis of tetrahydropyrimidine. The recombinant escherichia coli is obtained by knocking out a diaminapimelate decarboxylase lysA gene of escherichia coli E.coli MG1655 and introducing a tetrahydropyrimidine synthetic gene luster ectABC with a nucleotide sequence shown as SEQ ID NO. 1. The nucleotide sequence of the diaminapimelate decarboxylase lysA gene is shown as SEQ ID NO. 2. A thallus subjected to induced expression takes L-sodium aspartate as a substrate and the substrate is biologically converted to prepare the tetrahydropyrimidine. After conversion is carried out for 20 to 30h, the yield of the tetrahydropyrimidine reaches 2.5 to 3.5g/L, and therefore, the recombinant escherichia coli has relatively good industrial application value.

L-lysine can be produced by culturing an Escherichia coli cell in a culture medium, and collecting L-lysine from the culture medium, wherein the Escherichia coli cell is capable of producing L-lysine, is so modified that the activities of one or more enzymes involved in the synthetic pathway of meso-a,e-diaminopimelic acid (e.g., 2,3,4,5-tetrahydropyridine-2,6-dicarboxylate N-succinyltransferase, succinyldiaminopimelate transaminase, succinyldiaminopimelate desuccinylase, diaminopimelate epimerase) are decreased, and has a gene encoding diaminopimelate dehydrogenase introduced therein.

The invention is applicable to the technical field of plant cultivation, and provides an ornamental plant cultivation medium, a bottled ornamental plant and a preparation method of the bottled ornamental plant. A formula of the ornamental plant cultivation medium is as follows: a 1/2MS cultivation medium is used as a basic material, meanwhile 1.8-2.3 g/L of agar, 7-9 g/L of phytagel, 48-53 mg/L of diaminopimelic acid, 9.5-10.5 [mu]mol/L of PQQ and 23-26 mg/L of kanamycin are added, and then the pH value of the ornamental plant cultivation medium is adjusted to be 6.5-6.9. The provided cultivation medium can be used for accelerating plant growth, is also relatively firm, is suitable for long-time plant growth, and is particularly suitable for being used as the cultivation medium of the bottled ornamental plant; the plant is relatively vigorous in growth, relatively strong in stability, better in ornamental value and longer in growth cycle.

Process for the production of -lysine by constructing a recombinant microorganism which has a deregulated lysine 2,3-aminomutase gene and at least one deregulated gene selected from the group (i) which consists of aspartokinase, aspartatesemialdehyde dehydrogenase, dihydrodipicolinate synthase, dihydrodipicolinate reductase, tetrahydrodipicolinate succinylase, succinyl-amino-ketopimelate transaminase, succinyl-diamino-pimelate desuccinylase, diaminopimelate epimerase, diamino-pimelate dehydrogenase, arginyl-tRNA synthetase, diaminopimelate decarboxylase, pyruvate carboxylase, phosphoenolpyruvate carboxylase, glucose-6-phosphate dehydrogenase, transketolase, transaldolase, 6-phosphogluconolactonase, fructose 1,6-biphosphatase, homoserine dehydrogenase, phophoenolpyruvate carboxykinase, succinyl-CoA synthetase, methylmalonyl-CoA mutase, provided that if aspartokinase is deregulated as gene (i) at least a second gene (i) other than aspartokinase has to be deregulated, and cultivating said microorganism.

The invention relates to a Salmonella choleraesuis double-gene-deletion strain free of a resistance marker, Salmonella choleraesuis C7822 (with an accession number of CCTCC NO: M2011402 ). The strain is obtained by carrying out deletion of the asd gene, one of the important nutrition and metabolism genes of Salmonella choleraesuis, on Salmonella choleraesuis C7821 (with an accession number of CCTCC NO: M2010102 ) which has undergone deletion of the crp virulence gene. The gene-deletion strain C7822 loses the capability of synthesizing diaminopimelic acid (DAP), so the strain cannot survive in a DAP negative environment. After plasmids containing the asd gene are transformed into C7822, the asd gene in the plasmids can form a complementary gene with C7822, which enables C7822 to regain the capability of surviving in a DAP negative environment. The double-gene-deletion strain C7822 obtained in the invention has distinct genetic background, strong security and no resistance marker and can stably carry and express exogenous antigens; the double-gene-deletion strain is a good carrying vector and expression strain for exogenous antigens and has a wide application prospect.

The invention discloses meso-diaminopimelic acid dehydrogenase mutants with improved catalytic efficiency, and belongs to the technical field of gene engineering. According to the invention, single-site/double-site mutation is carried out on meso-diaminopimelic acid dehydrogenase shown as SEQ ID NO.2, and mutant enzymes D94A, W123K, D94A/W123K and W148K are successfully expressed and purified in escherichia coli. Enzyme activity measurement finds that the three meso-diaminopimelic acid dehydrogenase mutants have higher catalytic activity than the wild type, for example, the efficiencies of catalyzing phenylpyruvic acid by the mutant enzymes DAPDH-D94A, DAPDH-W123K and DAPDH-D94A/W123K are respectively improved by 3.5 times, 1.5 times and 1.3 times, and the enzyme activity of key enzymes issuccessfully improved.

The invention discloses a metabolic composition for pre-operative early warning of kidney delayed graft function of a donor donated after cardiac death. The metabolic composition is prepared from oneor more selected from seven metabolites including ascorbic acid, diaminopimelic acid, cinnamic acid, isobutyl-isobutyrate, androstenedione, 3-oxocaprylic acid and uroporphyrin. The invention further discloses a screening method of the metabolic composition. In the screened metabolic composition, the binding indication rate of ascorbic acid and diaminopimelic acid is 0.823, and the binding indication rate of cinnamic acid, isobutyl-isobutyrate, androstenedione, 3-oxocaprylic acid and uroporphyrin is 0.98.

The invention discloses an identification method of red norcardia cell wall skeleton. The method comprises the following steps: (1) sample spotting: using at least two silica-gel G thin-layer plates, spotting a proper amount of an alanine reference solution and a test sample solution on the first thin-layer plate; then spotting a proper amount of a meso-diaminopimelic acid reference solution and a test sample solution on the second thin-layer plate; (2) development: soaking the first thin-layer plate into a developing solvent composed of n-butanol-glacial acetic acid-water according to a volume ratio of 8:3:1, soaking the second thin-layer plate into a developing solvent composed of sodium dodecyl sulfate-n-butanol-n-hexane-water according to a volume ratio of 6:25:6:20; wherein the distance between the surface of the developing solvent to the bottom edge of the thin layer plate is in a range of 0.5 to 1.0 cm and the sample spots cannot be emerged by the developing solvent; sealing the top cover, when the developing solvent reaches the two thirds of the total length of the thin-layer plate, taking out the thin-layer plate, drying; (3) color developing; (4) observation. The identification method has the advantages of clear color development, high separation degree, and high reliability.

The invention provides a synthetic method of D-heterocyclic amino acid, a kit and an application. The synthetic method comprises the step that a keto acid compound of D-heterocycles is transformed into D-heterocyclic amino acid by diaminopimelic acid dehydrogenase shown as SEQ ID NO:1. The keto acid compound of D-heterocycles is transformed into D-heterocyclic amino acid by diaminopimelic acid dehydrogenase, so that non-natural chiral amino acid with higher transformation rate and higher ee can be obtained, the synthetic method based on diaminopimelic acid dehydrogenase adopts stable technological conditions and mild reaction conditions, the whole production process is simple to operate, less pollution is produced, and one new way of thinking is provided for artificial synthesis of D-heterocyclic amino acid.

This invention relates to an isolated nucleic acid fragment encoding a plant enzyme that catalyze steps in the biosynthesis of lysine, threonine, methionine, cysteine and isoleucine from aspartate, the enzyme a member selected from the group consisting of: dihydrodipicolinate reductase, diaminopimelate epimerase, threonine synthase, threonine deaminase and S-adenosylmethionine synthetase. The invention also relates to the construction of a chimeric gene encoding all or a portion of the enzyme, in sense or antisense orientation, wherein expression of the chimeric gene results in production of altered levels of the enzyme in a transformed host cell.

The present invention provides a method and composition for the treatment and prevention of an autoimmune disease such a multiple sclerosis which is mediated by autoreactive T cells. The administration of a NOD-1 agonist is shown to mediate an anti-inflammatory immune response. NOD-1 agonists suitable for use in the methods and compositions of the invention include diaminopimelic acid (DAP)-containing muropeptide compounds such as Tri-DAP and M-TriDAP.

The document describes biochemical pathways for producing 2- aminopimelate from 2,6-diaminopimelate, and methods for converting 2- aminopimelate to one or more of adipic acid, adipate semialdehyde, caprolactam, 6- aminohexanoic acid, 6-hexanoic acid, hexamethylenediamine, or 1,6-hexanediol by decarboxylating 2-aminopimelate into a six carbon chain aliphatic backbone and enzymatically forming one or two terminal functional groups, comprised of carboxyl, amine or hydroxyl group, in the backbone.

The invention provides a screening method of a medicine for treating citrus huanglongbing. The method comprises the following steps: 1) performing database comparison to obtain a succinyl diaminoheptanedioic acid desuccinylase gene sequence of Asia species of citrus huanglongbing; 2) carrying out mutation on amino acids at the fifth site and the fifteenth site of the succinyl diaminoheptanedioic acid desuccinylase protein sequence of the Asia species of citrus huanglongbing; 3) constructing a dimer protein with two active centers; 4) scoring molecular docking; 5) screening alternative compoundmolecules; 6) preparing a medicament for transfusion of citrus huanglongbing trees; 7) treating the sick trees; 8) taking phloem tissues of diseased branches, and extracting total DNA; and 9) selecting the alternative compound molecules with the most reduced germ concentration as target compound molecules by a PCR method. According to the screening method of the medicine for treating the citrus huanglongbing, the compound capable of treating the plant huanglongbing is obtained by molecular biological analysis and field screening.

The invention discloses a serum diaminopimelic acid detection kit based on liquid chromatography-mass spectrometry, a detection method and application, and belongs to the technical field of biological detection. The detection kit comprises an extraction reagent and a derivatization reagent; the extraction reagent comprises a DAP standard substance and a DAP isotope internal standard substance, and the derivatization reagent comprises a borate buffer solution and 6-aminoquinoline-N-succinimide methyl ester (AQC). Through research and development of the kit, the content of DAP in serum/plasma can be relatively rapidly and accurately quantified, and the repeatability is good. And the detection accuracy and stability can be improved by using the isotope internal standard. And the detection sensitivity can be improved by utilizing derivatization.

The invention discloses tricarboxylic acid cycle-free Escherichia coli chassis bacteria as well as a construction method and application thereof. The preparation method of the Escherichia coli chassis bacteria comprises the following steps: increasing the expression quantity and/or activity of tetrahydropyridine dicarboxylic acid: N-acetyltransferase, N-acetyl diaminopimelic acid deacetylase, N-acetyl diaminopimelic acid aminotransferase, O-acetyl homoserine thiolase and homoserine: O-acetyltransferasein host bacteria (Escherichia coli or mutant Escherichia coli), reducing the expression quantity and/or activity of tetrahydropicolinic acid: N-succinyltransferase and homoserine: O-succinyltransferase in the host bacteria, and obtaining the tricarboxylic acid cycle-free Escherichia coli chassis bacteria. Experiments prove that the Escherichia coli chassis bacteria can reduce the carbon loss rate and improve the capability of synthesizing a target product by taking central metabolic intermediates (such as acetyl coenzyme A, pyruvic acid and alpha-ketoglutaric acid) as precursors. The tricarboxylic acid cycle-free Escherichia coli chassis bacteria and the preparation method have an important application value.

A bacterium belonging to the genus Escherichia, which is transformed by introducing, into its cells, a DNA coding for a dihydrodipicolinate synthase originating from a bacterium belonging to the genus Escherichia having mutation to desensitize feedback inhibition by L-lysine and a DNA coding for an aspartokinase III originating from a bacterium belonging to the genus Escherichia having mutation to desensitize feedback inhibition by L-lysine; preferably a bacterium belonging to the genus Escherichia in which a dihydrodipicolinate reductase gene and a diaminopimelate dehydrogenase gene originating from Brevibacterium lactofermentum (or a succinyldiaminopimelate transaminase gene and a succinyldiaminopimelate deacylase gene) are further enhanced, is cultivated in an appropriate medium, L-lysine is produced and accumulated in a culture thereof, and L-lysine is collected from the culture.