Hydrazide as a ligand moiety in immobilized metal ion affinity chromatography - Separation of BO-IMI and BODIPY-hydrazide

BODIPY hydrazide (BO-HZ, a commercially available fluorescent dye) and BO-IMI (obtained by coupling the hydrazide moiety of BODIPY to the carboxyl group of N-acetylhistidine) were separated on three forms of a Sepharose-iminodiacetic acid column: Cu(II), Ni(LI) and Zn(II). Whereas BO-IMI eluted first on the Cu(II) and Ni(II) columns (a pH gradient from 7.0 to 2.0 was applied), it eluted last on the Zn(II) column. BO-HZ eluted from the Zn(II) column without displacing this metal. The explanation suggested for these results is that BODIPY hydrazide undergoes strong, bidendate binding only to the Cu(II) and Ni(II) columns. (C) 1997 Elsevier Science B.V.