53 results about "Peptide display" patented technology

The present invention relates to internalizing peptides which facilitate the uptake and transport of cargo into the cytoplasm and nuclei of cells as well as methods for the identification of such peptides. The internalizing peptides of the present invention are selected for their ability to efficiently internalize cargo into a wide variety of cell types both in vivo and in vitro. The method for identification of the internalizing peptides of the present invention comprises incubating a target cell with a peptide display library, isolating peptides with internalization characteristics and determining the ability of said peptide to internalize cargo into a cell.

The present invention relates to a method of selecting a protein variant having reduced immunogenicity as compared with the parent protein. This method includes the steps of screening a random peptide display package library with antibodies raised against any protein of interest, sequencing the amino acid sequence of the antibody binding peptides, or the DNA sequence encoding the antibody binding peptides, identifying epitope patterns of a protein by sequence alignment of the reactive peptide sequence, localization of epitope patterns on the primary 3-dimensional structure of the parent protein, defining an epitope area including amino acids situated within 5 Å from the epitope amino acids, and affecting antibody binding to the epitope, changing the localized epitope patterns, or amino acids defining the epitope area of the parent protein by genetic engineering mutations of a DNA sequence encoding the parent protein without impairing functionality of the protein using the emerging epitode database for eliminating amino acid substitutions creating new or duplicating existing epitope patterns, introducing the mutated DNA sequence into a suitable host, culturing the host and expressing the protein variant, and evaluating the immunogenicity of the protein variant using the parent protein as reference. The invention further relates to the protein variant and its use, as well as to a method for producing said protein variant.

The invention discloses a Caco-2 cell surface specific binding polypeptide. Four polypeptide fragments are screened by phage display of a random dodecapeptide library, and the amino acid sequences of the four polypeptide fragments are respectively as follows: SPSIDTRYSRLG, CVSVGMKPSPRP, SVSVGMKPSPRP and MVSMDSSPRDRL. According to the screening method disclosed by the invention, colorectal carcinoma Caco-2 cell binding polypeptide sequences are screened by a phage polypeptide display technology, the affinity of phage clones with colorectal carcinoma cells is judged by enzyme-linked immunosorbent assay (ELISA), ten phage clones are obtained, and four polypeptide sequences are obtained by sequencing. The consensus amino acid sequence is XXSXXXXXXXRXX; homology analysis indicates that the polypeptide motif is likely to be the amino acid determinant on the tumor cell surface receptor binding ligand protein; by further judgment of cell immunofluorescence, the targeting result of the phage positive clones implicates that the phage positive clones can be specifically bound with Caco-2 cells; and the colorectal carcinoma Caco-2 cell specific polypeptide acquired by screening provides a preliminary experiment basis for early diagnosis of colorectal carcinoma, targeted delivery of antitumor drugs and development of targeted small peptide drugs.

A bacteriophage T7 display vector for expressing and displaying an exogenous peptide, wherein the display vector comprises a polynucleotide encoding a bacteriophage T7 tail fiber protein p17 in which a hepatocyte-targeting determinant sequence is inactivated, and wherein a cloning site is contained in a coding sequence for the tail fiber protein p17 or in a coding sequence for a capsid protein p10B. Also provided are a host cell containing the display vector as described above, a bacteriophage T7 particle comprising at least one copy of a p17 protein which comprises an exogenous peptide displayed thereon, or at least one copy of a p10 protein with an exogenous peptide displayed thereon, wherein a hepatocyte-targeting determinant sequence on the bacteriophage T7 tail fiber protein p17 is inactivated. The present invention further provides a viral lysate containing assembled bacteriophage T7 particle described above, and a method for determining if a candidate peptide is a liver-targeting peptide, or for screening for liver targeting peptides.

This invention involves the phagemid in molecule biology field and medicine field. It is a preparation method of display peptide's phagemid. This method adopts the gene group plasmid of assistant phage fusion protein of coding foreign peptide and pIII coat protein, to co-transformation or successive-transformation F factor positive Isolates together with phagemid, so to obtain phagemid that display foreign peptide. The phagemid prepared by this method has high foreign peptide display level, and it is not necessarily prepare assistant phage so to simplified the process of preparation of assistant phage.

The present invention relates to a system and method for controlling peptide display valency on virus-like particles (VLPs), especially including MS2 or PP7 VLPs. In this method, large amounts of wild-type and low quantities of single-chain dimer coat proteins may be produced from a single RNA. Valency is controlled in immunogen (vaccine) production by providing a system that allows the production of large amounts of wild-type and low quantities of single-chain dimer coating proteins from a single RNA, allowing facile adjustment of display valency levels on bacteriophage VLPs, especially MS2 or PP7 VLPs over a wide range, from few than one—on average—to as many as ninety per particle. This facilitates the production of immunogens and vaccines, including VLPs exhibiting low valency. Nucleic acid constructs useful in the expression of virus-like particles are disclosed, comprised of a coat polypeptide of bacteriophage such as MS2 or PP7 modified by insertion of a heterologous peptide, optionally comprising a carbohydrate mimotope, wherein the heterologous peptide is displayed on the virus-like particle and encapsidates bacteriphage mRNA.

This invention relates to new vaccines against microorganisms based on antigenically mimetic peptides. The invention also relates to methods of discovering such mimetic peptides by first screening peptide-display phage libraries with antibodies against the microbial carbohydrates(s) of interest to locate antigenically mimetic peptides. Vaccines against Group B Streptococcus, or Streptococcus Agalactiae, are preferably produced using this method.

This invention is directed to a method for the expression of a gene of interest, or a chimeric or modified gene allowing the localization of a protein, protein fusion, peptide or fragment of interest within the extracellular domain of a floral cell. This method comprises preparing a construct comprising a promoter sequence capable of expressing a gene encoding the protein, protein fusion, peptide, or fragment of interest, within the floral cell; a translated sequence of the protein, protein fusion, peptide, or fragment of interest, which is localized within the extracellular domain of a floral cell; a gene that encodes the protein, protein fusion, peptide, or fragment of interest; and a terminator sequence, and transforming a plant. Plants transformed with such a construct are characterized as having a protein, fragment thereof, or peptide of interest on the surface of a floral cell. Such localized proteins or peptides may be used for the purposes of peptide display, mediating plant sterility, modifying pollen-pistil interactions, altering pollen for insect consumption etc.

The invention discloses polypeptide specifically bound to surface of an SGC-7901 cell. A random dodecapeptide library is displayed by bacteriophage to obtain five polypeptide segments in a screening manner; the amino acid sequences respectively are YTHNESSPKDTH, YTVPDYKHNSAH, THPWQITSVNFK, DVFPHSRPADEL and IHKDPANKSLVP. A polypeptide sequence bound to a gastric cancer SGC-7901 cell is screened by utilizing a phage peptide display technology; the affinity of phage clones and the gastric cancer is identified by enzyme-linked immuno sorbent assay (ELISA); 14 phage clones are obtained; five polypeptide sequences are obtained by sequencing. The homology analysis shows that the polypeptide sequence motif can be amino acid determinants bound to a tumor cell surface receptor on ligandin; the targeted results of positive phage clones are further identified by cell immunofluorescence to prompt the positive phage clones to be specifically bound to the SGC-7901 cell; an experimental evidence is provided for early diagnosis of the gastric cancer, targeted transportation of an antitumor medicament, and research and development of targeted short-peptide medicaments by the screened gastric cancer SGC-7901 cell specificity polypeptide.

The invention discloses a compound of Fab segment of anti-cancer drug Rituximab and CD20 antigen epitope peptide, which also provides the preparing method of compound and three-dimensional crystal structure of compound and application, wherein the three-dimensional crystal structure of compound displays the key residue interacted between Rituximab and antigen epitope peptide, which provides theoretical base for higher affinity and specificity antibody; the CD20 antigen epitope peptide displays peculiar ring-shaped structure, which is fit for sieving new antibody of epitope.

The present invention relates to a peptide bound to PD-L1 and uses for cancer immunotherapy and anticancer using the same, and the peptide of the present invention specifically binds to PD-L1 and inhibits it, thereby activating the function of immune cells against cancer cells and exhibiting anticancer effects. The peptides of the present invention selected two peptides (PD-L1Pep-1 and PD-L1Pep-2) that bind well to cells with high expression of human PD-L1 protein using phage peptide display technology and it was confirmed that it inhibits its function by binding to PD-L1 in humans and mice. The peptide of the present invention showed an effect similar level to that of an antibody and is relatively stable in blood, indicating a high potential as a cancer immunotherapy in the future.

The present invention provides an alternative scaffold for peptides displayed on filamentous phages through novel fusion proteins primarily originating from pVII. Libraries of filamentous phages can be created from fusion proteins, and a phage display system comprising a phagemid and a helper phage is a part of the invention. An aspect of the invention is a kit containing a phage display system comprising a phagemid and a helper phage that contains a nucleic acid encoding the fusion protein of the invention.

The invention relates to a peptide and a preparation method and application thereof. The peptide comprises a sequence as shown in SEQ ID No.1 or a sequence, where one or more amino acids are substituted, deleted, inserted and/added in the sequence as shown in SEQ ID No.1. The peptide displays activity of inhibiting melanoblast or melanogenesis or activity of whitening. The invention also providesa nucleotide sequence which encodes the peptide, a carrier containing the nucleotide sequence and a host comprising the vector. The peptide is similar to the amino acid sequence of MSH-alpha, and canbe prepared on a large scale by means of a biofermenting method, so that the peptide can be used for the whitening cosmetic industry.