SIMULTANEOUS MEASUREMENT OF 19 BINDING CONSTANTS OF PEPTIDES TO VANCOMYCIN USING AFFINITY CAPILLARY ELECTROPHORESIS-MASS SPECTROMETRY

On-line affinity capillary electrophoresis-electrospray ionization-mas s spectrometry (ACE-MS) was used for the simultaneous measurement of m ultiple binding constants of an all-D-tetrapeptide library to the mode l receptor, vancomycin. Determination of K-d values for the 19 peptide s of the form Fmoc-DXYA is demonstrated. The data are compared with th e results obtained for individual compounds using ACE-UV, and good cor relation between the two detection methods is shown. Simultaneous dete rmination of multiple K-d values by ACE-MS is achieved in one set of e xperiments, whereas only one K-d value can be obtained by ACE-UV durin g the same time. ACE-MS measures multiple binding constants in solutio n in a fast and reliable manner using femtomole amounts of samples.