Robert B Lobell

US Patent:

5525708, Jun 11, 1996

Filed:

Mar 28, 1994

Appl. No.:

8/220379

Inventors:

Karl H. Nocka - Harvard MA
Robert B. Lobell - Watertown MA

Assignee:

CytoMed, Inc. - Cambridge MA

International Classification:

C07K 1452

US Classification:

530409

Abstract:

A modified form of KL, the ligand for the c-Kit proto-oncogene, has been prepared wherein the protein is stabilized by an intermolecular covalent linkage. The protein can be prepared by expression of a recombinant protein which is dissolved in denaturant and refolded under conditions resulting in a disulfide linked dimer. Examples demonstrate the purification and characterization of this disulfide-linked cysteine dimer kit ligand (KL-CD) which contains at least one intermolecular disulfide bond and has at least ten-fold greater activity in promoting cell proliferation than native, non-covalently linked KL, as measured in in vitro assays.