Kaneka Corporation

Dai Murata

Shinichi Yoshida

Shunichi Taira

Keita Iguchi

Masayuki Takano

Yoshiyuki Nakano

Tomoyuki Nakaishi

Masahiro Hayashi

Kazunobu Minakuchi

Fuminori Konoike

Masakatsu Nishihachijyo

Junya Akagi

Takuma Suzuki

Hisako Yaura

The objective of the present invention is to provide a method for efficiently supporting a thiol group-including compound on an insoluble base material. The method for supporting a thiol group-including compound on an insoluble base material according to the present invention is characterized in comprising Step A: treating the thiol group-including compound with a thiol group-including organic reducing agent and an inorganic reducing agent, and Step B: contacting a reaction liquid of said Step A with the insoluble base material.

Method for supporting thiol group-including compound

An affinity separation matrix includes a water-insoluble base material; and a ligand that is immobilized on the water-insoluble base material, wherein the ligand is an antibody &#x3ba; chain variable region-binding peptide comprising B5 domain of Protein L derived from312 strain or a part thereof.

Affinity separation matrix for purifying protein containing immunoglobulin K chain variable region

A method for purifying an antibody or an antibody fragment containing &#x3ba;-chain variable region includes adsorbing at least one of the antibody or the antibody fragment onto an affinity separation matrix by contacting a liquid sample with the affinity separation matrix, washing the affinity separation matrix to remove impurities, and separating the at least one of the antibody or the antibody fragment from the affinity separation matrix by using an acetate buffer. The liquid sample includes the at least one of the antibody or the antibody fragment. The affinity separation matrix includes a water-insoluble carrier and a ligand selected from the group consisting of Protein L, a variant of Protein L, a domain of Protein L, and a variant of the domain. The ligand is immobilized on the water-insoluble carrier.

Method for purifying antibody or antibody fragment containing &#x3ba;-chain variable region

An object of the present invention is to provide a Fab region-binding peptide having an excellent ability for binding to a Fab region of IgG, an affinity separation matrix having the peptide as a ligand, and a method for producing a Fab region-containing protein, the method using the affinity separation matrix. Further, another object of the present invention is to provide a DNA encoding for the peptide, a vector containing the DNA, and a transformant which has been transformed by the vector. The Fab region-binding peptide according to the present invention is characterized in having a mutation at a specific site in comparison with wild-type SpG-&#x3b2;1.

Fab region-binding peptide

The objective of the present invention is to provide a peptide of which both of binding forces to a Fc region and a Fab region are superior. In addition, the objective of the present invention is to provide a DNA which encodes the peptide, a vector which contains the DNA, and a transformant which is transformed by the vector. The problem can be solved by providing the peptide having the specific sequence.

Immunoglobulin G-binding peptide

An object of the present invention is to create a novel engineered Protein A ligand having better antibody dissociation properties in the acidic condition compared with known engineered Protein A ligands. The present invention provides a protein having an affinity for an immunoglobulin, including an amino acid sequence obtained by introducing, into an amino acid sequence derived from any of E, D, A, B and C domains of Protein A, at least one amino acid substitution at any one or more of amino acid residues corresponding to positions 31 to 37 of the A, B and C domains (positions 29 to 35 of the E domain, positions 34 to 40 of the D domain), which are conserved in all the domains, the protein having a lower affinity for an Fab region of an immunoglobulin than a protein having the amino acid sequence before introduction of the substitution.

Protein capable of binding specifically to immunoglobulin, and immunoglobulin-binding affinity ligand

An object of the present invention is to provide a technique to create novel engineered protein ligands that, when immobilized through a lysine residue (its side chain &#x3b5;-amino group) which allows for efficient immobilization to a carrier, show the optimum binding capacity and binding efficiency to a target molecule. The present invention provides an engineered protein having a sequence obtained by replacing all the lysine residues in Protein A, which is the most typical protein ligand, with other amino acids, and adding lysine at a terminal; and an affinity separation matrix in which such an engineered protein is immobilized on a water-insoluble carrier by reductive amination or the like. This affinity separation matrix is characterized by its high binding capacity to a target molecule even when the immobilized amount of the ligand is small.

Protein for affinity-separation matrix

An object of the present invention is to develop techniques to create novel engineered protein ligands that maximize the binding capacity and binding efficiency to a target molecule of affinity separation matrices on which the protein ligands are immobilized. The present invention provides protein ligands (variants) that can be immobilized on carriers in a manner shown in schematic FIG.()-(), as well as antibody affinity separation matrices obtained by immobilizing such a protein ligand on a water-insoluble carrier. The affinity separation matrices are characterized by their excellent binding capacity and binding efficiency to a target molecule.

Protein ligand for affinity isolation matrix

An object of the present invention is to create a novel engineered Protein A ligand having better antibody dissociation properties in the presence of an acid than conventional engineered Protein A ligands and a further object of the present invention is to create a novel engineered Protein A ligand having higher alkali resistance. The present invention is to provide a protein having an affinity for an immunoglobulin, including an amino acid sequence derived from any of E, D, A, B and C domains of Protein A, wherein at least one Gly residue in the amino acid sequence is replaced with an amino acid other than Ala, and the protein has a lower affinity for an Fab region of an immunoglobulin than a protein including an amino acid sequence in which the Gly residue is replaced with Ala. Also, the present invention is to provide the protein having an affinity for an immunoglobulin, which has improved chemical stability in an alkaline condition compared to the corresponding domain.

Protein having affinity for immunoglobulin, and immunoglobulin-binding affinity ligand

An object of the present invention is to provide novel polypeptides that are capable of binding to an immunoglobulin and have high stability against alkali. The present invention relates to proteins having the amino acid sequence of SEQ ID No:1 or 2.

Immunoglobulin-binding polypeptide

The low-molecular-weight compound represented by the general formula (1): ArX-(Linker)-ArYHB (1), wherein ArX is a structure containing an optionally substituted aromatic six-membered ring, ArYHB is a structure containing an optionally substituted aromatic six-membered ring having a proton donor, the atom group 'Linker' has not less than 4 and not more than 30 atoms and binds ArX with ArYHB, is used for binding a proteinaceous substance.

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Hyogo, Japan

Dai Murata