Abstract: An object of the present invention is to provide a polypeptide having excellent alkaline stability and also allowing an immunoglobulin or a fragment thereof that has been bound to be eluted in a weakly acidic range, by modifying an amino acid sequence of an immunoglobulin-binding domain of Protein A. By substitution of serine at position 41 with an amino acid with a hydrophobic side chain, tyrosine, or histidine in each immunoglobulin-binding domain of Protein A, a polypeptide is obtained having avidity for an immunoglobulin or a polypeptide containing an Fc region thereof, having excellent alkaline stability, and also allowing the immunoglobulin or the polypeptide containing an Fc region thereof that has been bound to be efficiently eluted under weakly acidic mild conditions.

Abstract: The present inventors discovered affinity purification resins having sufficient binding affinity for Fc region variants with reduced binding to Protein A. Specifically, immunoglobulins containing an Fc region variant having reduced binding to Protein A could be purified using a Protein A-modified ligand containing a structure in which the amino acids of the C-domain have been substituted as an Fc ligand.

Abstract: An object of the present invention is to provide a polypeptide having a high binding capacity for an immunoglobulin kappa chain, and having excellent alkali stability, by modifying an amino acid sequence of an immunoglobulin-binding domain of Protein L derived from Peptostreptococcus magnus. A polypeptide having a high binding capacity for an immunoglobulin kappa chain, and having excellent alkali stability can be obtained by substituting specific lysine residues in an immunoglobulin-binding domain of Protein L derived from Peptostreptococcus magnus 3316 strain, with a basic amino acid or a hydroxyl group-containing amino acid.

Abstract: A multimeric immunoglobulin-binding protein having improved properties as an affinity ligand for affinity chromatography, and an insoluble support immobilizing such a multimer. The immunoglobulin-binding protein is represented by the formula: (R1)n-(R2)m, or (R2)m-(R1)n. R2 is an immunoglobulin-binding domain including an amino acid residue that covalently bonds to an insoluble support upon immobilization reaction with the insoluble support, and R1 is an immunoglobulin-binding domain without containing an amino acid residue the presence of which in the sequence compared to when it is absent in the sequence reduces the immunoglobulin-binding activity of the support yielded by the immobilization reaction. The immunoglobulin-binding protein satisfies: (1) n is an integer of 5 to 9; (2) m is an integer of 1 or 2; (3) the n (R1) domains may or may not have the same sequence; and (4) the total number of domains (n+m) is 6 to 10.

Abstract: An object of the present invention is to provide a polypeptide having a high binding capacity for an immunoglobulin kappa chain, and having excellent alkali stability, by modifying an amino acid sequence of an immunoglobulin-binding domain of Protein L derived from Peptostreptococcus magnus. A polypeptide having a high binding capacity for an immunoglobulin kappa chain, and having excellent alkali stability can be obtained by substituting specific lysine residues in an immunoglobulin-binding domain of Protein L derived from Peptostreptococcus magnus 3316 strain, with a basic amino acid or a hydroxyl group-containing amino acid.

Abstract: A multimeric immunoglobulin-binding protein having improved properties as an affinity ligand for affinity chromatography, and an insoluble support inmmobilizing such a multimer. The immunoglobulin-binding protein is represented by the formula: (R1)n-(R2)m, or (R2)m-(R1)n. R2 is an immunoglobulin-binding domain including an amino acid residue that covalently bonds to an insoluble support upon immobilization reaction with the insoluble support, and R1 is an immunoglobulin-binding domain without containing an amino acid residue the presence of which in the sequence compared to when it is absent in the sequence reduces the immunoglobulin-binding activity of the support yielded by the immobilization reaction. The immunoglobulin-binding protein satisfies: (1) n is an integer of 5 to 9; (2) m is an integer of 1 or 2; (3) the n (R1) domains may or may not have the same sequence; and (4) the total number of domains (n+m) is 6 to 10.

Abstract: Provided is affinity chromatography carrier for an immunoglobulin that simultaneously has high immunoglobulin-binding capability and chemical stability and that can be produced at low cost. An immunoglobulin-binding protein in which an amino acid substitution for not only maximizing the number of lysine residues on the protein surface of helix 3 and its periphery but also minimizing the number of lysine residues present on the protein surfaces of helix 1 and helix 2 as immunoglobulin-binding regions and/or an amino acid substitution for eliminating an aspartic acid-proline sequence have (has) been carried out, or a multimer thereof, is used as an affinity ligand for an affinity chromatography carrier.

Abstract: Provided is affinity chromatography carrier for an immunoglobulin that simultaneously has high immunoglobulin-binding capability and chemical stability and that can be produced at low cost. An immunoglobulin-binding protein in which an amino acid substitution for not only maximizing the number of lysine residues on the protein surface of helix 3 and its periphery but also minimizing the number of lysine residues present on the protein surfaces of helix 1 and helix 2 as immunoglobulin-binding regions and/or an amino acid substitution for eliminating an aspartic acid-proline sequence have (has) been carried out, or a multimer thereof, is used as an affinity ligand for an affinity chromatography carrier.

Abstract: This invention relates to a novel chemically synthesized gene including a base sequence coding for the primary amino acid sequence of natutal-type streptokinase, a corresponding plasmid recombinant, corresponding transformant and process for preparing streptokinase by the incubation of the transformant, the invention further relating to novel streptokinase derivative proteins having streptokinase activity and a modified primary amino acid sequence corresponding to the primary amino acid sequence of natural-type streptokinase which is deficient in the amino acid residues at the 373-position to the C-terminus, and wherein at least one of the amino acid residues may be deficient, replaced or inserted; the chemically synthesized gene including a base sequence coding for the derivative protein, plasmid containing the gene, transformant transformed by the plasmid, and process for preparing the streptokinase derivative protein by the incubation of the transformant.

Abstract: A process for producing L-serine by the combination of chemical synthesis and enzyme chemical synthesis is disclosed. In this process L-serine is biochemically produced from 2-oxo-axazolidine-4-carboxylic acid or a salt thereof.

Abstract: A process for producing L-aspartyl-L-phenylalanine alkyl or aryl esters wherein L-aspartic acid and L-phenylalanine which is esterified with an alkyl group having at least two carbon atoms, an aryl group or an aralkyl group, are contacted in an aqueous medium with particular microorganisms or enzyme fractions from these microorganisms and the condensed product crystallizes out due to insolubility in the aqueous medium.