Cell surface antigen that binds with L6 monoclonal antibody

US5200508A · kind A · utility

Assignee

• The State of Oregon acting by and through the State Board of Higher Education on behalf of Oregon Health Sciences University · US

Inventors

• Gajanan Nilaver · Portland, US
• Lawrence Rosenbaum · Portland, US
• Edward A. Neuwelt · Portland, US

Key dates

• Filing date: Dec 12, 1991
• Grant date: Apr 6, 1993
• Expiry date: Dec 12, 2011

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07K2317/34
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

We disclose the discovery and purification of a tumor antigen that binds the mouse monoclonal antibody L6. Immunohistochemical analysis showed that the antigen is expressed on the membrane surface of LX-1 human lung tumor cells, which retain L6 binding activity when intracerebrally xenografted in nude rats. The antigen is also expressed in the cytoplasm of hypothalamic neurons. Inability of oxytocin and vasopressin hormones to block L6 binding showed that the antigenic epitope resides in neurophysin, the carrier protein associated with the two hormones. Porcine neurophysin did block L6 binding to the antigen. Western blot analysis confirmed that L6-immunoreactivity is neurophysin-related. Immunoaffinity chromatography and gel electrophoresis revealed the antigen molecular weight to be 45000 daltons. Amino-terminal sequencing revealed a 21-amino acid homology with the N-terminus of human pro-pressophysin.