2489 results about "Bacteriophage" patented technology

The invention provides immunoglobulin polypeptides comprising variant amino acids in CDRs of antibody variable domains. In one embodiment, the polypeptide is a variable domain of a monobody and has a variant CDRH3 region. These polypeptides provide a source of great sequence diversity that can be used as a source for identifying novel antigen binding polypeptides. The invention also provides these polypeptides as fusion polypeptides to heterologous polypeptides such as at least a portion of phage or viral coat proteins, tags and linkers. Libraries comprising a plurality of these polypeptides are also provided. In addition, methods of and compositions for generating and using these polypeptides and libraries are provided.

Peripheral blood leucocytes incubated with a semi-synthetic phage antibody library and fluorochrome-labeled CD3 and CD20 antibodies were used to isolate human single chain Fv antibodies specific for subsets of blood leucocytes by flow cytometry. Isolated phage antibodies showed exclusive binding to the subpopulation used for selection or displayed additional binding to a restricted population of other cells in the mixture. At least two phage antibodies appeared to display hithereto unknown staining patterns of B lineage cells. This approach provides a subtractive procedure to rapidly obtain human antibodies against known and novel surface antigens in their native configuration, expressed on phenotypically defined subpopulations of cells. Importantly, this approach does not depend on immunization procedures or the necessity to repeatedly construct phage antibody libraries.

The invention provides a method for selecting, from a repertoire of polypeptides, a population of functional polypeptides which bind a target ligand in a first binding site and a generic ligand in a second binding site, which generic ligand is capable of binding functional members of the repertoire regardless of target ligand specificity, comprising the steps of: a) contacting the repertoire with the generic ligand and selecting functional polypeptides bound thereto; and b) contacting the selected functional polypeptides with the target ligand and selecting a population of polypeptides which bind to the target ligand. The invention accordingly provides a method by which a polypeptide repertoire is preselected, according to functionality as determined by the ability to bind the generic ligand, and the subset of polypeptides obtained as a result of such preselection is then employed for further selection according to the ability to bind the target ligand.

Anti-VEGF antibodies and variants thereof, including those having high affinity for binding to VEGF, are disclosed. Also provided are methods of using phage display technology with naïve libraries to generate and select the anti-VEGF antibodies with desired binding and other biological activities. Further contemplated are uses of the antibodies in research, diagnostic and therapeutic applications.

The present invention describes peptides capable of specifically binding to preselected micromolecules or to their natural receptor. The preselected molecules include but are not limited to drugs, vitamins, neuromediators and steroid hormones. Methods of using the phage display libraries to identify peptide compositions in preselected binding interactions are also disclosed. The retrieved peptides mimicking a natural receptor binding site to preselected molecules are used as is or as ligands to re-screen the same or different libraries to find and / or derive new receptor ligands, or are used to elicit the production of antibodies capable of binding to the natural receptor. The two categories of effector molecules (peptides or antibodies) may find diagnostic, therapeutic or prophylactic uses. The peptides directly derived from the phage display libraries may be used as drug detectors or antidotes. The others may be used to identify, target, activate or neutralize the receptor for the preselected micromolecules, the receptor being known or unknown.

The invention includes a method of treating gastrointestinal diseases associated with species of genus Clostridium such as clostridium deficit in human patients with gastrointestinal disorders having an etiological component such as a microbial agent producing a toxin where treated with an antimicrobial composition an amount effective to inhibit or eliminate the microbial agent. The antimicrobial composition in a form of probiotic mixture can be administrated alone or in combination with an antimicrobial agent, such as a bacteriophage which is specific for a bacterium producing toxin or antibiotics which are then used to eliminate or inhibit the clostridial species overgrown in a patient's gastrointestinal tract. Disorders that can be treated by the method of the invention include diarrhea or inflammatory bowel diseases such as colitis or Crohn's disease.

The invention provides comprising variant amino acids in CDRs of antibody variable domains. These polypeptides provide a source of great sequence diversity that can be used as a source for identifying novel antigen binding polypeptides. The invention also provides these polypeptides as fusion polypeptides to heterologous polypeptides such as at least a portion of phage or viral coat proteins, tags, and linkers. Libraries comprising a plurality of these polypeptides are also provided. In addition, methods of and compositions for generating and using these polypeptides and libraries are provided.

The present method describes the use of thio-phosphate as a feed source for micro-organisms and multi-cellular organisms. This compound enters into nucleotide pools and ultimately into polymers of both RNA and DNA forming stable phosphorothioate internucleotide linkages. The method enables the microbial synthesis of both plasmid and phage DNA substituted with phosphorothioate. Furthermore, methods are described for the preparation of phosphorothioate oligo mixtures from recombinant phage DNA grown in modified media for use in antisense studies.

The present invention provides a method for obtaining site-specific recombination in a eukaryotic cell, the method comprising providing a eukaryotic cell that comprises a first recombination attachment site and a second recombination attachment site; contacting the first and second recombination attachment sites with a prokaryotic recombinase polypeptide, resulting in recombination between the recombination attachment sites, wherein the recombinase polypeptide can mediate recombination between the first and second recombination attachment sites, the first recombination attachment site is a phage genomic recombination attachment site (attP) or a bacterial genomic recombination attachment site (attB), the second recombination site is attB or attP, and the recombinase is selected from the group consisting of a Listeria monocytogenes phage recombinase, a Streptococcus pyogenes phage recombinase, a Bacillus subtilis phage recombinase, a Mycobacterium tuberculosis phage recombinase and a Mycobacterium smegmatis phage recombinase, provided that when the first recombination attachment site is attB, the second recombination attachment site is attP and when the first recombination attachment site is attP, the second recombination attachment site is attB. The invention also describes compositions, vectors, and methods of use thereof, for the generation of transgenic cells, tissues, plants, and animals. The compositions, vectors and methods of the present invention are also useful in gene therapy applications.

Stocks of infectious rAAV are generated using yeast strains, bacterial strains, and bacteriophages engineered to express the required AAV proteins and harboring rAAV vector sequences. Stocks of rAAV virions of all serotypes and pseudotypes can be generated in prokaryotic and eukaryotic cells using the methods described herein.

The invention relates to posttranslational modification of phage-displayed polypeptides. These displayed polypeptides comprise at least one unnatural amino acid, e.g., an aryl-azide amino acid such asp-azido-L-phenylalanine, or an alkynyl-amino acid such as para-propargyloxyphenylalanine, which are incorporated into the phage-displayed fusion polypeptide at a selected position by using an in vivo orthogonal translation system comprising a suitable orthogonal aminoacyl-tRNA synthetase and a suitable orthogonal tRNA species. These unnatural amino acids advantageously provide targets for posttranslational modifications such as azide-alkyne [3+2]cycloaddition reactions and Staudinger modifications.

Anti-VEGF antibodies and variants thereof, including those having high affinity for binding to VEGF, are disclosed. Also provided are methods of using phage display technology with naïve libraries to generate and select the anti-VEGF antibodies with desired binding and other biological activities. Further contemplated are uses of the antibodies in research, diagnostic and therapeutic applications.

The invention relates to a neutralizing antibody for resisting a novel coronavirus SARS-Cov-2 and an application of the neutralizing antibody. The antibody at least comprises one of a heavy chain CDR1, a heavy chain CDR2, a heavy chain CDR3, a light chain CDR1, a light chain CDR2 and a light chain CDR3. The antibody can be used for preparing a diagnostic reagent or a diagnostic kit, a drug or a pharmaceutical composition for detecting, preventing and treating a COVID-19. According to the neutralizing antibody, differential antibody screening is carried out through a phage display technology ina manner of targeting SARS-Cov-2-RBD and SARS-Cov-1-RBD; the neutralizing antibody for resisting the novel coronavirus SARS-Cov-2 is obtained; binding of the SARS-Cov-2-RBD and ACE2 positive cells can be blocked; and the neutralizing antibody has a remarkable virus neutralizing effect on an SARS-Cov-2 pseudo virus and provides an effective alternative antibody drug for prevention and treatment ofthe COVID-19.