Abstract: The method of the invention provides for the formation of a recombinant polypeptide which has been modified at the C-terminal end through the use of a transpeptidation process. The method is suitable for modifying recombinant polypeptides of any source including those which may be commercially available, those derived from recombinant single copy or multicopy polypeptide constructs, or those derived from single or multicopy recombinant fusion protein constructs. The transpeptidation reaction involves contacting an endopeptidase enzyme with a recombinant polypeptide to substitute an addition unit, of one or more amino acids, for a leaving unit, linked to a core polypeptide through a cleavage site recognized by the endopeptidase enzyme. Recombinant polypeptides derived from multicopy polypeptide constructs may be cleaved from the multicopy polypeptide at the N-terminal and C-terminal ends and simultaneously under go substitution of the leaving unit by the desired addition unit.

Abstract: The present invention is directed to a protein purification construct having three tandem, coupled segments composed of a binding protein, an interconnecting linker and a variable fused polypeptide which incorporates the one or more copies of a product peptide. The binding protein is a mammalian or human carbonic anhydrase, or a modified version of the carbonic anhydrase. The protein purification construct may be employed in methods for expression of the product peptide in microbial and higher organism and for ligand immobilized affinity purification of the product peptide.

Abstract: The method of the invention provides for the formation of a recombinant polypeptide which has been modified at the C-terminal end through the use of a transpeptidation process. The method is suitable for modifying recombinant polypeptides of any source including those which may be commercially available, those derived from recombinant single copy or multicopy polypeptide constructs, or those derived from single or multicopy recombinant fusion protein constructs. The transpeptidation reaction involves contacting an endopeptidase enzyme with a recombinant polypeptide to substitute an addition unit, of one or more amino acids, for a leaving unit, linked to a core polypeptide through a cleavage site recognized by the endopeptidase enzyme. Recombinant polypeptides derived from multicopy polypeptide constructs may be cleaved from the multicopy polypeptide at the N-terminal and C-terminal ends and simultaneously under go substitution of the leaving unit by the desired addition unit.

Abstract: A method is provided for preparing a labeled protein, immobilized protein or protein-bioactive agent composition by attaching a label, support or bioactive agent to a protein by exopeptidase catalysis at a site that is remote from the active site of the protein. More specifically, an amine or alcohol group of an amino acid, amine or alcohol nucleophile is reacted by exopeptidase catalysis with a C-terminus carboxylic acid group of a protein such as an antibody, enzyme or hormone to couple the nucleophile to the protein to form an adduct, and the adduct is bound to an auxiliary substance such as a support, label or bioactive agent or its combination with a linker arm by reacting a reactive substituent of the nucleophile with a reactive group of the auxiliary substance. Alternatively, the nucleophile is bound to the auxiliary substance or its combination with a linker arm to form an intermediate, and the intermediate is coupled by exopeptidase catalysis to the protein.

Abstract: The method of the invention provides for the formation of a recombinant polypeptide which has been modified at the C-terminal end through the use of a transpeptidation process. The method is suitable for modifying recombinant polypeptides of any source including those which may be commercially available, those derived from recombinant single copy or multicopy polypeptide constructs, or those derived from single or multicopy recombinant fusion protein constructs. The transpeptidation reaction involves contacting an endopeptidase enzyme with a recombinant polypeptide to substitute an addition unit, of one or more amino acids, for a leaving unit, linked to a core polypeptide through a cleavage site recognized by the endopeptidase enzyme. Recombinant polypeptides derived from multicopy polypeptide constructs may be cleaved from the multicopy polypeptide at the N-terminal and C-terminal ends and simultaneously under go substitution of the leaving unit by the desired addition unit.

Abstract: The invention provides for a chemical method for preparing a recombinant single copy polypeptide or a portion thereof with a modified terminal amino acid .alpha.-carbon reactive group selected from the group consisting of N-terminal .alpha.-amine, C-terminal .alpha.-carboxyl, and a combination thereof. The steps of the method involve forming the recombinant single copy polypeptide or a portion thereof so that the single copy polypeptide is protected with one or more biologically added protecting groups at the N-terminal .alpha.-amine, C-terminal .alpha.-carboxyl. The recombinant single copy polypeptide can then be reacted with up to three chemical protecting agents to selectively protect reactive side chain groups and thereby prevent side chain groups from being modified. The recombinant single copy polypeptide can be cleaved with at least one cleavage reagent specific for the biological protecting group to form an unprotected terminal amino acid .alpha.-carbon reactive group.

Abstract: The invention provides for a chemical method for preparing a recombinant single copy polypeptide or a portion thereof with a modified terminal amino acid .alpha.-carbon reactive group selected from the group consisting of N-terminal .alpha.-amine, C-terminal .alpha.-carboxyl, and a combination thereof. The steps of the method involve forming the recombinant single copy polypeptide or a portion thereof so that the single copy polypeptide is protected with one or more biologically added protecting groups at the N-terminal .alpha.-amine, C-terminal .alpha.-carboxyl. The recombinant single copy polypeptide can then be reacted with up to three chemical protecting agents to selectively protect reactive side chain groups and thereby prevent side chain groups from being modified. The recombinant single copy polypeptide can be cleaved with at least one cleavage reagent specific for the biological protecting group to form an unprotected terminal amino acid .alpha.-carbon reactive group.

Abstract: Methods are presented for producing and purifying a variable fusion polypeptide which can be purified by affinity chromatography with the binding protein partner. The variable fusion polypeptide construct has tandem coupled segments containing one or more copies of a desired peptide linked to carbonic anhydrase as the purification binding protein. In the methods, the fusion protein is expressed in a recombinant host using a recombinant vector containing a gene encoding the fusion polypeptide. Then the expressed fusion polypeptide is purified by immobilized reversible inhibitor affinity chromatography. Finally, the purified fusion polypeptide is cleaved from the desired peptides by chemical or enzymatic means and the desired peptides purified with affinity chromatography.

Abstract: The method of the invention provides for the formation of a recombinant polypeptide which has been modified at the C-terminal end through the use of a transpeptidation process. The method is suitable for modifying recombinant polypeptides of any source including those which may be commercially available, those derived from recombinant single copy or multicopy polypeptide constructs, or those derived from single or multicopy recombinant fusion protein constructs. The transpeptidation reaction involves contacting an endopeptidase enzyme with a recombinant polypeptide to substitute an addition unit, of one or more amino acids, for a leaving unit, linked to a core polypeptide through a cleavage site recognized by the endopeptidase enzyme. Recombinant polypeptides derived from multicopy polypeptide constructs may be cleaved from the multicopy polypeptide at the N-terminal and C-terminal ends and simultaneously under go substitution of the leaving unit by the desired addition unit.

Abstract: The invention is directed to a method of purifying sequentially synthesized peptides and oligonucleotides by affinity techniques. Selected products are capped with and N-terminus capping agent for peptides or a 5'-terminus capping agents for oligonucleotides, and then bound with affinity agents that are selective for the corresponding capping agents.

Abstract: The invention provides a means for attaching a label, support or bioactive agent to a protein with an exopeptidase at a site that is remote from the active site of the protein. More specifically the invention is directed to a method for the attachment of an amino acid, amine and alcohol nucleophile to the carboxyl terminus of a protein. In one embodiment, a labeled nucleophile is attached to a protein such as an antibody. In other embodiments, the invention is directed to a method for the attachment of a protein to an immobilization support and to a method for the attachment of a bioactive agent to a protein.

Abstract: An auxiliary substance such as a label, support, or bioactive agent is attached to a protein at a site that is remote from the active site of the protein by the use of exopeptidase and a nucleophile which is an amino acid, amino acid derivative, amine or alcohol. In one embodiment, the nucleophile is attached to the carboxy terminus of a protein by catalysis with exopeptidase to form an adduct and then the adduct or its combination with a linker arm is bound to the auxiliary substance. In another embodiment, the auxiliary substance or its combination with a linker arm is bound to the nucleophile to form an intermediate substance which is then coupled by catalysis with exopeptidase to the carboxy terminus of a protein.

Abstract: The invention is directed to a method of purifying sequentially synthesized peptides and oligonucleotides by affinity techniques. Selected products are capped with and N-terminus capping agent for peptides or a 5'-terminus capping agents for oligonucleotides, and then bound with affinity agents that are selective for the corresponding capping agents.

Abstract: The invention is directed to a method for purifying sequentially synthesized peptides and oligonucleotides by immunoaffinity techniques. Selected products are lapped with an antigenic capping agent and are conjugated with antibodies that are specific for the capping agent.