GSBS Student Publications


Coupling tandem affinity purification and quantitative tyrosine iodination to determine subunit stoichiometry of protein complexes

UMMS Affiliation

Graduate School of Biomedical Sciences; Program in Molecular Medicine; Program in Gene Function and Expression



Document Type


Medical Subject Headings

Electrophoresis, Polyacrylamide Gel; Fungal Proteins; Indicators and Reagents; Iodine Radioisotopes; Kinetics; Polymerase Chain Reaction; Radioisotope Dilution Technique; Tyrosine; Yeasts


Life Sciences | Medicine and Health Sciences


Rapid protein purification methodologies, such as strategies involving the tandem affinity purification module, have resulted in the identification of a tremendous number of multisubunit protein complexes. Furthermore, in this modern genomic age, mass spectrometry methods are often coupled with affinity purification to identify the genes that encode each protein subunit. However, simple methodologies to determine the stoichiometry of individual subunits within a multisubunit complex have not received much attention. In this article we describe a procedure to rapidly and efficiently determine the stoichiometry of subunits within multisubunit complexes using a combination of tandem affinity purification and quantitative 125I labeling of subunit tyrosines.

Rights and Permissions

Citation: Methods. 2003 Sep;31(1):104-9.

Related Resources

Link to Article in PubMed

Journal Title

Methods (San Diego, Calif.)

PubMed ID