Specific Flow Injection Sandwich Binding Assay for IgG Using Protein A and a Fusion Protein

verfasst von
Wiebke Brandes, Hans Eckhard Maschke, Thomas Scheper
Abstract

A sandwich-type flow-injection binding assay for quantitation of various IgG's was developed. The assay is based on the pseudoimmunological reaction between protein A from Staphylococcus aureus and immunoglobulin G from different species. Protein A immobilized on a solid support and a fusion protein of protein A and β-galactosidase from Escherichia coli are used for detection. The fusion protein is produced with a temperature-inducible recombinant E. coli strain. A sandwich is formed by subsequent injection of IgG and fusion protein into the buffer stream flowing through the immobilized protein A column. The amount of enzyme activity bound is proportional to the amount of IgG bound and is measured by pumping a lactose solution as substrate for β-galactosidase through the protein A column. Lactose is converted to glucose and galactose. The detector is an enzyme thermistor that measures the heat evolved in the enzymatic conversion of glucose by coimmobilized glucose oxidase and catalase. The assay takes 16 min at a flow rate of 0.6 mL min-1 with a lower detection limit of 33 pmol per injection of rabbit IgG. The precision of replicate measurements has a standard deviation of 4–5%, and the column can be used for more than 50 cycles.

Externe Organisation(en)
Westfälische Wilhelms-Universität Münster (WWU)
Medizinische Hochschule Hannover (MHH)
Typ
Artikel
Journal
Analytical chemistry
Band
65
Seiten
3368-3371
Anzahl der Seiten
4
ISSN
0003-2700
Publikationsdatum
01.12.1993
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Analytische Chemie
Elektronische Version(en)
https://doi.org/10.1021/ac00071a006 (Zugang: Unbekannt)