Enzymatically inactive, immunologically-active .beta.-galactosidase muetin, process for making and uses thereof

US4963469A · kind A · utility

Assignee

• Boehringer Mannheim GmbH · DE

Inventors

• Ralf Mattes · Stuttgart, DE
• Helmut Lenz · Tutzing, DE
• Werner Stock · Gräfelfing, DE

Key dates

• Filing date: Jul 12, 1988
• Grant date: Oct 16, 1990
• Expiry date: Jul 12, 2008

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S435/962
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The present invention provides an enzymatically-inactive, immunologically-active .beta.-galactosidase mutein, wherein, in the region between the amino acids 430 and 550, at least one amino acid of the natural sequence is changed to another amino acid and the enzymatic activity does not amount to more than 1%, referred to the native enzyme. The present invention also provides a process for the production of this mutein. Furthermore, the present invention is concerned with the use of this mutein in the immunological determination of serum proteins by the enzyme immunoassay principle.