Genetically engineered enzymes and their conjugates for diagnostic assays

US5843634A · kind A · utility

Assignee

• Abbott Laboratories · US

Inventors

• Elaine M. Brate · Grayslake, US
• Catherine A. Brennan · Libertyville, US
• Dominique P. Bridon · Morton Grove, US
• Keeve D. Jaffe · Pleasant Prairie, US
• Grant A. Krafft · Glenview, US
• Wlodzimierz Mandecki · Libertyville, US
• Steven C. March · Libertyville, US
• John Russell · Pleasant Prairie, US
• Vincent T. Yue · Deerfield, US

Key dates

• Filing date: Jun 4, 1996
• Grant date: Dec 1, 1998
• Expiry date: Jun 4, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07K2319/40
• WIPO field: Biotechnology
• WIPO sector: Chemistry

Abstract

This invention relates to genetically engineered enzymes, their ligand conjugates, their manufacture, and their use in qualitative or quantitative assays. A hybrid enzyme, such as an AP-epitope, has a foreign amino acid moiety (an epitope) inserted near the active site of the starting AP enzyme. The foreign amino acid moiety binds with an analyte, and, as a consequence of this binding, the enzymatic activity of the hybrid enzyme, AP-epitope, is modified. The changes in the enzymatic activity are dependent upon the presence, or the amount, of the analyte. In another embodiment, the hybrid enzyme consists of a cysteine introduced near the active site of an AP to give a hybrid enzyme. The cysteine on the hybrid enzyme serves as a point of conjugation of a ligand, such as theophylline, ferritin, thyroxine, or digoxigenin, to form the hybrid enzyme-ligand conjugate. The ligand binds with an antibody, an analyte or a binding molecule to an analyte and as a result of this binding, the enzymatic activity of the hybrid enzyme-ligand conjugate is modified or modulated.