Spiegelmers are high-affinity L-enantiomeric oligonucleotide ligands that display high resistance to enzymatic degradation compared with D-oligonucleotides. The target binding properties of Spiegelmers can be designed by an in vitro-selection process starting from a random pool of oligonucleotides. Applying this method, a Spiegelmer with high affinity (K D ؍ 20 nM) for the peptide hormone, gonadotropin-releasing hormone (GnRH) was isolated. The Spiegelmer acts as an antagonist to GnRH in Chinese hamster ovary cells stably expressing the human GnRH receptor, and its activity is unchanged by linking to 40-kDa polyethylene glycol. In a castrated rat model the Spiegelmer further demonstrated strong GnRH antagonist activity, which is more pronounced and persists longer with the polyethylene glycol-linked derivative. Furthermore, in rabbits the anti-GnRH Spiegelmer was shown to have a very low, possibly negligible immunogenic potential. These studies suggest that Spiegelmers could be of substantial interest in the development of new pharmaceutical approaches against GnRH and other targets.in vitro selection ͉ mirror-image oligonucleotide ͉ animal model ͉ aptamer ͉ immunogenicity S piegelmers are mirror-image, high-affinity oligonucleotide ligands composed of L-ribose or L-2Ј-deoxyribose units. The chiral inversion results in high stability in plasma compared with natural D-oligonucleotide ligands, aptamers, suggesting that Spiegelmers may display favorable in vivo behavior and present future potential for therapeutic and diagnostic applications (1). Spiegelmers thus offer a promising alternative to aptamers, the limited in vivo stability of which continues to be a major obstacle to clinical development despite extensive efforts to improve the structure of the oligonucleotide backbone (2, 3).Spiegelmers can fold into distinct three-dimensional structures generating high-affinity ligands that can be selected against defined pharmacological targets. High-affinity Spiegelmers with the desired target-binding properties can be identified by using an adaptation of the SELEX (systematic evolution of ligands by exponential enrichment) procedure (4). Because L nucleic acids are not compatible with SELEX because of the enantio specificity of the enzymes used for amplification, a ''mirror-image'' SELEX approach is used. The first step is to select an aptamer against the enantiomeric form of the natural target. After trimming to the minimal binding motif, the equivalent L form of the aptamer, the Spiegelmer, then is synthesized, and because of the reciprocal chirality, this Spiegelmer binds with high affinity to the natural target. The basic concept of combining molecular evolution with chiral inversion stemmed from the identification of a D-peptide ligand for the SH3 domain of c-Src by using a phage display approach (5). Mirror-image RNA ligands to adenosine and arginine as well as an enantiomeric DNA specific for vasopressin were identified by mirror-image SELEX and have been described previously (1, 6, 7).Gonadotropin-releasi...
Mirror-image oligonucleotide ligands (Spiegelmers) that bind to the pharmacologically relevant target gonadotropin-releasing hormone I (GnRH) with high affinity and high specificity have been identified using the Spiegelmer technology. GnRH is a decapeptide that plays an important role in mammalian reproduction and sexual maturation and is associated with several benign and malignant diseases. First, aptamers that bind to D-GnRH with dissociation constants of 50-100 nM were isolated out of RNA and DNA libraries. The respective enantiomers of the DNA and RNA aptamers were synthesized, and their binding to L-GnRH was shown. These Spiegelmers bind to L-GnRH with similar affinity to that of the corresponding aptamers that bind to D-GnRH. We further demonstrated dose-dependent inhibition of GnRH-induced Ca(2+) release in Chinese hamster ovary cells that were stably transfected with the human GnRH receptor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.