Bionebraska, Inc.

University of Nebraska

Restoragen, Inc.

Jay S Stout

Fred W Wagner

Dwane E Wylie

Thomas R Coolidge

Sheldon M Schuster

Bruce E Partridge

Dennis B Henriksen

William Lewis

Bart Holmquist

Gino Van Heeke

Shane Manning

Julie A Frank

Barton Holmquist

Randall R Carlson

Malcolm Riddell

Klaus Breddam

Daniel J Strydom

Dan Dormady

The invention provides a method of producing a polypeptide having a C-terminal &agr;-carboxamide group. It particularly concerns an enzymatic modification of selected substrate polypeptides which result in cleavage of the substrate polypeptide to form a product peptide with a C-terminal arginine residue having an &agr;-carboxamide group (C-terminal &ldquo;Arg-NH &rdquo;). The method includes contacting an aqueous-based solution including (i) ammonia reagent and (ii) the substrate polypeptide with (iii) clostripain.

Clostripain catalyzed amidation of peptides

A process for the recombinant preparation of a calcitonin fragment and the use of the fragment in the preparation of calcitonin and related analogs is provided. The process includes recombinantly forming a fusion protein which includes the calcitonin fragment linked to a carbonic anhydrase. The recombinantly formed fusion protein is subsequently cleaved to produce a polypeptide which includes the calcitonin fragment. A method for producing a calcitonin carba analog which includes condensing a desaminononapeptide with the recombinantly formed calcitonin fragment is also provided.

Recombinant preparation of calcitonin fragments and use thereof in the preparation of calcitonin and related analogs

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. The invention utilizes known and newly discovered cleavage recognition sites to effectuate the desired modification products.

Enzymatic method for modification of recombinant polypeptides

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.

Purification cloning of peptides

A method for the production of C-terminal amidated recombinant peptides is provided. The method employs a recombinant protein construct having multiple copies of a target peptide linked by intraconnecting peptides. The intraconnecting peptides permit the multicopy construct to be selectively reacted to produce product peptides having a C-terminal .alpha.-carboxamide. A recombinant gene containing a DNA sequence coding for the recombinant protein construct and an expression cassette, an expression vector and a transformed cell including the recombinant gene are also provided.

Production of C-terminal amidated peptides from recombinant protein

Recombinant preparation of calcitonin fragments and use thereof in the

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. The exopeptidase may be a serine or cysteine exocarboxypeptidase.

Exopeptidase catalyzed site-specific bonding of supports, labels and

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. The unprotected terminal amino acid .alpha.-carbon reactive group is modified with at least one chemical modifying agent. The side chain protected terminally modified single copy polypeptide is then deprotected at the side chain groups to form a terminally modified recombinant single copy polypeptide. The number and sequence of steps in the method can be varied to achieve selective modification at the N- and/or C-terminal amino acid of a recombinantly produced polypeptide.

Chemical method for selective modification of the N-  and/or C-terminal

Chemical method for selective modification of the N- and/or C-terminal

The invention provides method and kits for detecting a metallic cation in a sample of a body fluid. The preferred method and kits include the use of at least two different types of antibodies having different specificities. In the preferred method, the sample of body fluid can be contacted with an effective amount of a capture antibody specific for a naturally occurring polypeptide that can bind the metallic cation to form a first antigen-antibody complex. An effective amount of an antibody specific for an epitope on a metallic cation-naturally occurring polypeptide complex or an antibody specific for a metallic cation is added to the first antigen-antibody complex to form a second antigen-antibody complex. The amount of the metallic cation in the sample of body fluid is determined by detecting the amount of the second antigen-antibody complex.

Monoclonal antibody assay and kit for detecting metal cations in body

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.

Growing community of inventors

Lincoln, NE, United States of America

Jay S Stout