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:
Aug. 07, 1990
Filed:
Aug. 14, 1987
Jonathan R Beckwith, Cambridge, MA (US);
Kathryn L Strauch, Brighton, MA (US);
President and Fellows of Harvard College, Cambridge, MA (US);
Abstract
This invention features a method of isolating a mutant strain of Escherichia coli, having a defective periplasmic protease, the method comprising the steps of: mutagenizing an E. coli cell, wherein the cell comprises: (a) an inner and an outer membrane, (b) a periplasmic space between the membranes, (c) a protein which in a first state is mobile, being able to move through the outer membrane and enter medium surrounding the cells, the protein in the first state being detectable in the medium, and in a second state is not mobile, remaining inside the cell, and (d) a periplasmic protease which converts the protein from the second state to the first state in the cell, and selecting a mutant cell which produces a reduced level of the detectable protein in the medium compared to the E. coli cell, wherein the mutant cell comprises the defective periplasmic protease. This invention also features mutant strains of E. coli having a defective periplasmic protease.