The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 07, 1998
Filed:
Feb. 13, 1995
David V Goeddel, Hillsborough, CA (US);
Glenn C Rice, Palo Alto, CA (US);
David W Leung, Foster City, CA (US);
Genentech, Inc., South San Francisco, CA (US);
Abstract
A screening method for the selection of mutagenized proteins that are normally secreted by cells is described. The method includes the development of a cloning vector for the expression of secretory proteins as fusion proteins on the cell surface of transfected mammalian cells. The secreted protein is displayed on the cell surface by fusion with the glycophospholipid membrane anchor of decay accelerating factor (DAF). Tissue-type plasminogen activator (t-PA), which is normally secreted, is used as a model protein. PCR mutagenesis is used to generate random mutations within the Kringle 1 (K1) domain of t-PA. Fluorescence activated cell sorting (FACS) is employed to screen for t-PA mutants possessing a loss of an epitope to a specific Mab, whose nonlinear binding domains overlap with the t-PA clearance receptor contact regions novel t-PA mutants designated N115S, N1425S, and K159R were discovered by this method.