Binding Stoichiometry of an Antibody Fragment

Antibody fragments, especially Fab-fragments, have emerged as a tool to facilitate the crystal growth and improve crystal quality of membrane proteins. This application note demonstrates the measurement of binding stoichiometry using the powerful method of multi-angle light scattering in combination with size exclusion chromatography (MALS-SEC). This information is instrumental in further biophysical studies and co-crystallization experiments. Additional information such as weight fraction of protein and detergent in the protein-detergent micelle are obtained in the same experiment when using both UV and RI-detectors.