185 results about "Toxin protein" patented technology

The subject invention relates to the surprising discovery that toxin complex (TC) proteins, obtainable from Xenorhabdus, Photorhabdus, and Paenibacillus, can be used interchangeably with each other. In particularly preferred embodiments of the subject invention, the toxicity of a “stand-alone” TC protein (from Photorhabdus, Xenorhabdus, or Paenibacillus, for example) is enhanced by one or more TC protein “potentiators” derived from a source organism of a different genus from which the toxin was derived. As one skilled in the art will recognize with the benefit of this disclosure, this has broad implications and expands the range of utility that individual types of TC proteins will now be recognized to have. Among the most important advantages is that one skilled in the art will now be able to use a single set of potentiators to enhance the activity of a stand-alone Xenorhabdus protein toxin as well as a stand-alone Photorhabdus protein toxin. (As one skilled in the art knows, Xenorhabdus toxin proteins tend to be more desirable for controlling lepidopterans while Photorhabdus toxin proteins tend to be more desirable for controlling coleopterans.) This reduces the number of genes, and transformation events, needed to be expressed by a transgenic plant to achieve effective control of a wider spectrum of target pests. Certain preferred combinations of heterologous TC proteins are also disclosed herein. Other objects, advantages, and features of the subject invention will be apparent to one skilled in the art having the benefit of the subject disclosure.

The present invention relates to the field of recombinant toxin protein production in bacterial hosts. In particular, the present invention relates to production processes for obtaining high levels of a recombinant CRM197, Diphtheria Toxin, Pertussis Toxin, Tetanus Toxoid Fragment C, Cholera Toxin B, Cholera holotoxin, and Pseudomonas Exotoxin A, from a bacterial host.

The invention provides a bacterial traceless genetic manipulation vector. The vector contains a toxin inverse-screening element controlled by an antitoxin switch and an antibiotics resistance gene. The invention also provides a construction method of the vector and a method for application of the vector in bacterial traceless gene knock-out, knock-in, replacement, point mutation and insertion and deletion of large DNA fragments (larger than 194kb). By the utilization of a constitutive promoter for continuous expression of toxin protein and by the utilization of an inducible promoter for inducible expression of antitoxin protein, the toxin inverse-screening element (TCCRAS) controlled by the antitoxin switch is established, and the problem that specificity of existing genetic manipulation systems of gram-positive bacterium is not high, the systems are instable and screening is difficult is solved.

This invention relates to novel compositions of botulinum toxin that can be applied topically for various therapeutic, aesthetic and/or cosmetic purposes. The compositions may include botulinum toxin complexes, wherein the amounts of hemagglutinin, non-toxin non-hemagglutinin and/or exogenous albumin are selectively and independently reduced compared to conventional commercially available botulinum toxin. The compositions may further contain molecules that are not native to botulinum toxin and that bind non-covalently to the botulinum toxin complexes, thereby acting as skin-tropic “adhesion molecules” to improve the ability of the toxin complexes to adhere to and to penetrate the skin epithelium. The compositions have an improved safety profile compared to existing botulinum-containing compositions that are injected subcutaneously. Methods for the use of such compositions are also contemplated by this invention.

The present invention provides for immunogenic compositions and their methods of use as vaccines and their method of preparation. These immunogenic compositions comprise a recombinant protein of toxin A or toxin B of Clostridium difficile conjugated to a polysaccharide of a microbial pathogen. The immunogenic compositions may include only a truncated portion of toxin A or toxin B, particularly the repeating units (rARU or rBRU), that is associated with a microbial pathogen polysaccharide. Such compositions are effective in eliciting T-cell dependent and antibody responses. These compositions are therefore effective as vaccines for humans, particularly children, and animals in affording protection against one or more microbial pathogens.

The invention relates to the technical field of biologics, in particular to a method for extracting a toxin protein which causes vascular permeability increase from white cyanea tentacles. The method comprises the following steps: unfreezing fresh white cyanea tentacles which are frozen at a super-low temperature at a low temperature, washing by a small quantity of buffer solution, collecting the buffer solution, centrifuging to obtain a supernatant and using the supernatant as cyanea crude toxin, and sequentially separating by an ion chromatographic column and a gel chromatographic column to obtain the toxin protein CnP45 which causes vascular permeability increase, wherein the molecular weight of the toxin protein is 45kD. The extracting process of the jellyfish toxin is simplified, the interference of impurity proteins is reduced, and an important method instruction is provided for the further separation and purification of jellyfish toxin ingredients.

The invention relates to a detection kit for helicobacter pylori virulence protein antibody and a detection method by using the same. The kit comprises a microwell plate, an enzyme-labeled secondary antibody, a negative control serum, a positive control serum, a substrate, a stop buffer and a washing liquor, wherein the microwell plate is coated with purified recombinant helicobacter pylori virulence proteins, the substrate is a solution containing 1% m/m 3, 3', 5, 5'-tetramethyl benzidine and 30% v/v hydrogen peroxide, and the recombinant helicobacter pylori virulence proteins are cytotoxin-associated protein CagA, vacuolating toxin protein VacA, flagellum protein subunit A, flagellum protein subunit B, urease subunit A, and urease subunit B. According to the invention, six purified helicobacter pylori virulence proteins are used as antigens which itself have high conservatism and specificity and are related to the symptom of a patient, so the kit has characteristics of high specificity, identification capacity for helicobacter pylori clinical strain virulence strength, and semi-quantitative detection capacity.

The invention discloses expression and preparation methods for a polyvalent multi-specific antibody and an immune hybrid protein and belongs to the technical field of biology. According to the invention, by using characteristics of protein Intein, a novel method for preparing polyvalent specific antibodies, or antibody and cell factor merged hybrid immunoproteins, or antibody and toxin protein merged immunotoxins or antibody and other active protein merged immune hybrid proteins is designed and developed. According to the methods, products, i.e., the polyvalent specific antibody and the immune hybrid protein are prepared through expressing all parts of the hybrid protein separately in appropriate procaryotic or eucaryotic cell systems, carrying out high-performance affinity-chromatography purification and separation, and then, carrying out splicing in vitro under the condition of intein splicing. The methods have high production efficiency, are wide in applicable application range and facilitate the separation and purification of the products. The invention provides a novel method for preparing biological drugs for directional attack on cancers or other diseases.

A bacterial toxin protein such as a Shiga toxin protein is efficiently produced using plant cells. The plant cells are transformed using a DNA construct containing DNA encoding a hybrid protein in which the bacterial toxin proteins such as the Shiga toxin proteins are tandemly linked through a peptide having the following characteristics (A) and (B) to produce the bacterial toxin protein in the plant cells: (A) a number of amino acids is 12 to 30; and (B) a content of proline is 20 to 35%.

The invention provides a bovine type-A clostridium perfringens subunit vaccine and a preparation method and an application thereof. The subunit vaccine comprises a bovine type-A clostridium perfringens alpha-toxin protein truncation body and a pharmacologically acceptable adjuvant. The bovine type-A clostridium perfringens alpha-toxin protein truncation body is an antigen determinant amino acid sequence from 255th to 372nd amino acids of alpha-toxin protein. The subunit vaccine has the following advantages that 1) safety problems due to uncompleted inactivation are not existed; 2) the qualityis controllable, and the difference between the batches is not existed; 3) the production equipment and space requirement is low, the expression level is high, and the cost is low; and 4) toxin dispersion risk is not existed, and the safety of operators can be guaranteed.

The invention discloses a method for efficiently preparing recombinant active scorpion insect neurotoxin LqhIT2. The method mainly comprises a step (1) of optimizing and synthesizing LqhIT2 genes with C- ends provided with 6*His labels according to amino acid sequences of mature LqhIT2 toxins and characteristics of a pichia pastoris expression system and constructing pichia pastoris secretory expression vectors; a step (2) of converting recombinant vectors into a pichia pastoris host, and through screening, obtaining yeast transformants in high-level secretory expression; a step (3) of expressing recombinant scorpion insect neurotoxin LqhIT2 proteins in the pichia pastoris host, and quickly obtaining the recombinant scorpion insect neurotoxin LqhIT2 proteins with the purity over 98% through a Ni2+ affinity chromatography method, wherein the purified recombinant proteins have very strong poisonous activity on insect cells. The method is modified based on conventional expression of insect neurotoxin LqhIT2 through prokaryotic host escherichia coli, the method of using eukaryotic host pichia pastoris to express the insect neurotoxin LqhIT2 is explored, and the yeast transformants in high-level secretory expression are screened.

The present invention includes recombinant proteins derived from Clostridium botulinum toxins. In particular, soluble recombinant Clostridium botulinum type A, type B and type E toxin proteins are provided. Methods which allow for the isolation of recombinant proteins free of significant endotoxin contamination are provided. The soluble, endotoxin-free recombinant proteins are used as immunogens for the production of vaccines and antitoxins. These vaccines and antitoxins are useful in the treatment of humans and other animals at risk of intoxication with clostridial toxin.

The invention discloses a method for producing recombinant scorpion toxin protein by adopting a silkworm as a parasitifer, which mainly comprises the following steps: adopting a scorpion cDNA as a template, adopting 5'-ACGTAGATCTATGGATGGATATATAAG-3' containing BglII enzyme cutting site as a forward primer and adopting 5'-ACGTAGATCT TTACTTTTTTCCAC-3' containing the BglII enzyme cutting site as a reverse primer to carry out PCR gene amplification reaction in 32 cycles to obtain a scorpion toxin gene; digesting pCR2.1-scorpion toxin by restriction endonuclease BglII to obtain a scorpion toxin gene fragment; cloning the scorpion toxin gene fragment in a baculovirus transfer vector pAcGP67b to obtain a recombinant pAcGP67b-scorpion toxin gene, carrying out homologous recombination with baculovirus BmNPV DNA of a silkworm in an insect cell by cotransfection to produce a recombinant virus; expressing in a silkworm body and purifying the recombinant scorpion toxin. Most of the recombinant scorpion toxin protein expressed by a silkworm larva is retained in a fat body of the silkworm; the scorpion toxin is purified from the fat body by an affinity chromatography; and the recombinant scorpion toxin has obvious biological toxicity, is suitable for the requirement of a biopharmaceutical industrialization level and has wide application prospect in the field of future medical and clinic treatment.

The invention relates to a clostridium perfringen alpha toxin genetic engineering vaccine and application thereof. The clostridium perfringen alpha toxin genetic engineering vaccine is prepared by designing a specific primer, implementing polymerase chain reaction (PCR) amplification on A-type clostridium perfringen DNA to obtain an alpha toxin gene segment, cloning the gene segment onto a pMD18-T Vector, selecting a positive recon and linking the positive recon onto a PET-28 alpha (+) plasmid; introducing the recombinant plasmid to a receptor strain to successfully construct a recombinant strain BL21 (DE3)-alpha; emulsifying the prepared alpha toxin protein and an aluminum hydroxide adjuvant at a volume ratio of 9:1, and adding 0.01% thiomersal to obtain the clostridium perfringen alpha toxin genetic engineering vaccine. The clostridium perfringen alpha toxin genetic engineering vaccine is easy for realization of industrial production, simple to operate and good in safety, and is capable of effectively preventing such diseases as animal necrotic enteritis, enterotoxemia, and human and animal traumatic gas gangrene caused by the A-type clostridium perfringens.