Creative Biomolecules, Inc.

Stryker Corporation

Micromet Ag

Richard J Ridge

Charles M Cohen

James S Huston

Peter C Keck

Thangavel Kuberasampath

Hermann Oppermann

David C Rueger

Marc F Charette

Roberto Crea

Disclosed is a method for the isolation and purification of polypeptides expressed in host cells by recombinant DNA techniques. A fused polypeptide is produced containing a desired polypeptide fused to additional amino acids. The additional amino acids define a leader sequence having properties exploitable in purification, a hinge region, and a cleavage site. The hinge region is cysteine-free and has a secondary structure which serves to expose the cleavage site to a selected endopeptidase. The method of the invention involves the production of a fused polypeptide which may be efficiently isolated by exploiting the properties of the leader sequence, and then efficiently cleaved at the cleavage site in an appropriate aqueous environment by virtue of the influence of the hinge on the cleavage agent/cleavage site reaction and other properties of the fused polypeptide.

Product and process for the production, isolation, and purification of recombinant polypeptide

Disclosed is a novel polypeptide useful as a leader or trailer peptide moiety in recombinant DNA protein production techniques involving fused protein methodology. The polypeptide comprises an amphiphilic helix designed at the DNA level to have hydrophilic charged amino acid residues on one side of the barrel of the helix and nonpolar amino acid residues on the other side of the barrel of the helix. When DNA encoding the helix is attached to a gene encoding a protein of interest, high level expression is achieved and inclusion bodies are spontaneously formed. The inclusion bodies may be collected and purified easily by altering the ionic strength and/or pH of media used to dissolve the inclusion bodies. After purification, the fused protein is cleaved to separate the amphiphilic helix from the product.

Leader sequences for the production of recombinant proteins

Recombinant DNA enclosed amphiphilic leader sequences for the production

Disclosed is a novel polypeptide useful as a leader or trailer peptide moiety in recombinant DNA protein production techniques involving fused protein methodology The polypeptide comprises an amphiphilic helix designed at the DNA level to have hydrophilic charged amino acid residues on one side of the barrel of the helix and nonpolar amino acid residues on the other side of the barrel of the helix. When DNA encoding the helix is attached to a gene encoding a protein of interest, high level expression is achieved and inclusion bodies are spontaneously formed. The inclusion bodies may be collected and purified easily by altering the ionic strength and/or pH of media used to dissolve the inclusion bodies. After purification, the fused protein is cleaved to separate the amphiphilic helix from the product.

A matrix for implantation in a mammalian host comprising biocompatible, mineral-free, insoluble Type-I bone collagen which may be allogenic or xenogenic to the host, and which, when implanted in the host, is biodegradable. The collagen is treated with a collagen fibril modifying substance such as acidified acetonitrile, chloroform, or dichloromethane, or by heating in an aqueous environment to a temperature of 37.degree.-65.degree. C. The treated material undergoes a change in morphology involving a significant increase in its surface area as measured by various methods. Under the scanning electron microscope the material has an 'oyster shell' appearance with many pits and micropores.

Bone collagen matrix for implants

Disclosed is a matrix material for implantation in a mammalian host comprising biocompatible mineral-free type I bone collagen, xenogenic to the host, and biodegradable therewithin. The matrix is manufactured from protein-extracted bone powder treated with certain swelling agents to increase its surface area and porosity. The matrix may be combined with osteogenic protein to induce reliably and reproducibly endochondral bone formation. It also can be used as a surface coat around implantable prosthetic devices to promote cellular ingrowth or as a carrier for sustained release of various therapeutic compositions.

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Acton, MA, United States of America

Richard J Ridge