Miller BT, Collins TJ (2003) Production and characterization of biotinylated gonadotropin-releasing hormone analogs conjugated to avidinylated saporin. Neuroscience 2003 Abstracts 325.15. Society for Neuroscience, New Orleans, LA.
Summary: Saporin is a potent protein cytotoxin derived from the seeds of the plant Saponaria officinalis. Although unmodified saporin cannot permeate cellular membranes in appreciable amounts, this toxin can be chemically conjugated to various compounds that can enter cells by receptor-mediated uptake. When such conjugates are internalized, saporin can exert a lethal effect by inactivating cellular ribosomes. Thus, when conjugated to compounds that bind to specific cellular receptors, saporin can potentially be used as a relatively precise, targeted toxin. A major challenge in employing saporin-based technologies resides in the construction of conjugates of saporin and various receptor-binding biomolecules. Linking a small, bioactive peptide to saporin must be carried out in such a way as to retain the specific receptor-binding properties of the peptide. Although the successful direct conjugation of a small number of bioactive peptides to saporin has been reported, not all such conjugate preparations are necessarily homogeneous. In theory, the recent commercial availability of avidinylated saporin could allow investigators to utilize the numerous, well-characterized, bioactive, biotinylated peptides that have been developed over the past 25 years. Consequently, we explored the ability of conjugates fashioned from biotinylated analogs of gonadotropin-releasing hormone (GnRH) and avidinylated saporin to selectively target GnRH receptor-bearing pituitary cells. The biotinylated GnRH analogs all contained biotin moieties chemically linked to the epsilon amino group of [D-Lys6]GnRH; single and double spacer arms of aminohexanoic acid were included between the peptide and the biotin group. Some biotinylated GnRH analogs contained disulfide bonds between the peptide and biotin moieties. After conjugating the biotinylated peptides to avidinylated saporin, we tested the specific cytotoxic effect of the conjugates in cultures of dispersed rat pituitary cells.
Related Products: Avidinylated-SAP (Cat. #IT-09)