Advances in partial filling multiple injection affinity capillary electrophoresis (PFMIACE) to estimate binding constants of receptors and ligands

CHED 178

Alejandra Ramirez, Department of Chemistry and Biochemistry, California State University Los Angeles, 5151 State University Drive, Los Angeles, CA 90032 and Frank Gomez, Department of Chemistry and Biochemistry, California State University, Los Angeles, 5151 State University Dr, Los Angeles, CA 90032.
Partial filling multiple injection affinity capillary electrophoresis (PFMIACE) is used to determine binding constants (Kb) between carbonic anhydrase B (CAB, E.C.4.2.1.1) and arylsulfonamide ligands. In this technique, the capillary is partially filled with ligand at increasing concentrations, a non-interacting standard, three or four separate plugs of receptor each separated by small plugs of buffer, a plug containing a second non-interacting standard, and then electrophoresed in buffer. Upon continued electrophoresis, an equilibrium is established between the ligand and receptors causing a shift in the migration time of the receptors with respect to the non-interacting standards. This change in migration time is utilized for estimating multiple values of Kb for the interaction. As an extension to PFMIACE we have employed a voltage gradient technique that allows for less ligand to be used than in traditional ACE experiments. Here, values for Kb are obtained for charged arylsulfonamides. In addition, a competitive binding assay for analyzing neutral arylsulfonamides to CAB is demonstrated. A comparison of values for Kb is made between PFMIACE and the voltage gradient technique.

 

Undergraduate Research Poster Session: Analytical Chemistry
2:30 PM-4:30 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Poster

Division of Chemical Education

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006