Synthesis of multivalent polymer–aptamer conjugates with enhanced inhibitory potency

Abstract

PurposeWe are interested in designing a modular strategy for creating potent multivalent ligands, which frequently can be used as effective inhibitors of undesired biomolecular interactions. For example, such inhibitors might prevent the self-assembly of bacterial toxins or the attachment of a virus to its host cell receptors.MethodsWe used a biocompatible polyamino acid polymer as a scaffold for grafting multiple copies of an oligonucleotide aptamer (OA). Specifically, the carboxylates on the side chains of polyglutamic acid (PGA) were modified with a thiol-reactive linker, N-aminoethyl maleimide (AEM), and thiol-functionalized OAs were attached to the maleimide moieties. The resulting conjugates were tested for their ability to compete with and inhibit the binding of unconjugated monovalent OAs to the target cell receptor.ResultsMultivalent PGA–OA conjugates with low, medium, and high valency were successfully prepared. The varying valency and successful purification to remove unconjugated OAs were confirmed by polyacrylamide gel electrophoresis. The resulting purified conjugates inhibited the binding of unconjugated monovalent OAs, and the measured half maximal inhibitory concentration (IC50) values corresponded to a 38–88-fold enhancement of potency on a per-aptamer basis, relative to OA alone.ConclusionMultivalent conjugation of OA ligands has potential as a generally useful way to improve the potency of the interaction between the ligand and its target receptor. We have demonstrated this principle with a known OA as a proof of concept as well a synthetic strategy that can be used to synthesize multivalent conjugates of other OAs.

Recombinant Protein Micelles to Block Transduction by SARS-CoV-2 Pseudovirus

“…This could originate from steric effects due to micelle size or due to the multivalency of micelles. 47 , 48 Both in vitro and in vivo studies are therefore necessary to compare micelles and free mini-binders for different variants under the same experimental setup.…”

Improving Breast Cancer Treatment Specificity Using Aptamers Obtained by 3D Cell-SELEX

“…The concept of multivalency, where multiple ligands bind simultaneously to multiple targets, in particular to receptors on a cell surface, has been used for enhancing binding affinity of aptamers in different contexts and designs [ 64 , 65 , 66 , 67 ]. Various types of constructs have been designed to achieve multivalency: Multimeric constructs, connected with nucleic acid, peptide, or artificial linkers [ 37 , 48 , 68 , 69 , 70 , 71 , 72 , 73 ] of predefined length to tune the spacing in between aptamers, or nanoparticles [ 35 , 43 , 74 , 75 , 76 , 77 , 78 , 79 ] or liposomes [ 62 , 64 , 80 , 81 , 82 ] decorated with aptamers with pre-defined density. Polymeric designs as we report here have not been used widely in the construction and application of multimeric aptamers [ 37 , 70 , 71 , 72 , 73 ].…”

“…Various types of constructs have been designed to achieve multivalency: Multimeric constructs, connected with nucleic acid, peptide, or artificial linkers [37,48,[68][69][70][71][72][73] of predefined length to tune the spacing in between aptamers, or nanoparticles [35,43,[74][75][76][77][78][79] or liposomes [62,64,[80][81][82] decorated with aptamers with pre-defined density. Polymeric designs as we report here have not been used widely in the construction and application of multimeric aptamers [37,[70][71][72][73]. This design has several advantages.…”

Macromolecular Effects in Medicinal Chemistry※

“…为了 进一步增强抗体结合抗原的能力, 研究者们设计出一些 聚合物修饰的多价抗体, 可以产生多重作用甚至是多特 异性作用 [69][70][71] . 核酸适配体的识别也依赖于多价作用, 化 学 学 报 综述 566 http://sioc-journal.cn 可以通过聚合物缀合核酸适配体来提高其多价结合效 率 [72] , 也可以通过多价设计开发具有疾病诊断及治疗 等多重功能的多价体系 [73] .…”