Inventors:
Elaine M Brate - Grayslake IL
Catherine A. Brennan - Libertyville IL
Dominique P. Bridon - Morton Grove IL
Keeve D. Jaffe - Trevor WI
Grant A. Krafft - Glenview IL
Wlodzimierz Mandecki - Libertyville IL
Steven C. March - Libertyville IL
John C. Russell - Greenfield WI
Vincent T. Yue - Deerfield IL
Assignee:
Abbott Laboratories - Abbott Park IL
International Classification:
C12N 916
C12N 1555
C12Q 144
C07K 1900
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.