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Qu H, Zheng M, Ma Q, Wang L, Mao Y, Eisenstein M, Tom Soh H, Zheng L. Allosteric Regulation of Aptamer Affinity through Mechano-Chemical Coupling. Angew Chem Int Ed Engl 2023; 62:e202214045. [PMID: 36646642 DOI: 10.1002/anie.202214045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 01/06/2023] [Accepted: 01/16/2023] [Indexed: 01/18/2023]
Abstract
The capacity to precisely modulate aptamer affinity is important for a wide variety of applications. However, most such engineering strategies entail laborious trial-and-error testing or require prior knowledge of an aptamer's structure and ligand-binding domain. We describe here a simple and generalizable strategy for allosteric modulation of aptamer affinity by employing a double-stranded molecular clamp that destabilizes aptamer secondary structure through mechanical tension. We demonstrate the effectiveness of the approach with a thrombin-binding aptamer and show that we can alter its affinity by as much as 65-fold. We also show that this modulation can be rendered reversible by introducing a restriction enzyme cleavage site into the molecular clamp domain and describe a design strategy for achieving even more finely-tuned affinity modulation. This strategy requires no prior knowledge of the aptamer's structure and binding mechanism and should thus be generalizable across aptamers.
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Affiliation(s)
- Hao Qu
- School of Food and Biological Engineering and Engineering Research Center of Bioprocess of Ministry of Education, Hefei University of Technology, Hefei, 230009, China
| | - Manyi Zheng
- School of Food and Biological Engineering and Engineering Research Center of Bioprocess of Ministry of Education, Hefei University of Technology, Hefei, 230009, China
| | - Qihui Ma
- School of Food and Biological Engineering and Engineering Research Center of Bioprocess of Ministry of Education, Hefei University of Technology, Hefei, 230009, China
| | - Lu Wang
- School of Food and Biological Engineering and Engineering Research Center of Bioprocess of Ministry of Education, Hefei University of Technology, Hefei, 230009, China
| | - Yu Mao
- School of Food and Biological Engineering and Engineering Research Center of Bioprocess of Ministry of Education, Hefei University of Technology, Hefei, 230009, China
| | - Michael Eisenstein
- Department of Electrical Engineering and Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | - Hyongsok Tom Soh
- Department of Electrical Engineering and Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | - Lei Zheng
- School of Food and Biological Engineering and Engineering Research Center of Bioprocess of Ministry of Education, Hefei University of Technology, Hefei, 230009, China
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Sun YJ, Chen WD, Liu J, Li JJ, Zhang Y, Cai WQ, Liu L, Tang XJ, Hou J, Wang M, Cheng L. A Conformational Restriction Strategy for the Control of CRISPR/Cas Gene Editing with Photoactivatable Guide RNAs. Angew Chem Int Ed Engl 2023; 62:e202212413. [PMID: 36453982 DOI: 10.1002/anie.202212413] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 12/05/2022]
Abstract
The CRISPR/Cas system is one of the most powerful tools for gene editing. However, approaches for precise control of genome editing and regulatory events are still desirable. Here, we report the spatiotemporal and efficient control of CRISPR/Cas9- and Cas12a-mediated editing with conformationally restricted guide RNAs (gRNAs). This approach relied on only two or three pre-installed photo-labile substituents followed by an intramolecular cyclization, representing a robust synthetic method in comparison to the heavily modified linear gRNAs that often require extensive screening and time-consuming optimization. This tactic could direct the precise cleavage of the genes encoding green fluorescent protein (GFP) and the vascular endothelial growth factor A (VEGFA) protein within a predefined cutting region without notable editing leakage in live cells. We also achieved light-mediated myostatin (MSTN) gene editing in embryos, wherein a new bow-knot-type gRNA was constructed with excellent OFF/ON switch efficiency. Overall, our work provides a significant new strategy in CRISPR/Cas editing with modified circular gRNAs to precisely manipulate where and when genes are edited.
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Affiliation(s)
- Ying-Jie Sun
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Wen-Da Chen
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ji Liu
- BNLMS, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Jun-Jin Li
- State Key Laboratory of Agrobiotechnology and College of Biological Science, China Agricultural University, Beijing, 100193, China
| | - Yu Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Wei-Qi Cai
- BNLMS, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Li Liu
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xin-Jing Tang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Jian Hou
- State Key Laboratory of Agrobiotechnology and College of Biological Science, China Agricultural University, Beijing, 100193, China
| | - Ming Wang
- BNLMS, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Liang Cheng
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Hangzhou, 310024, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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Di Gioacchino A, Procyk J, Molari M, Schreck JS, Zhou Y, Liu Y, Monasson R, Cocco S, Šulc P. Generative and interpretable machine learning for aptamer design and analysis of in vitro sequence selection. PLoS Comput Biol 2022; 18:e1010561. [PMID: 36174101 PMCID: PMC9553063 DOI: 10.1371/journal.pcbi.1010561] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 10/11/2022] [Accepted: 09/12/2022] [Indexed: 12/03/2022] Open
Abstract
Selection protocols such as SELEX, where molecules are selected over multiple rounds for their ability to bind to a target of interest, are popular methods for obtaining binders for diagnostic and therapeutic purposes. We show that Restricted Boltzmann Machines (RBMs), an unsupervised two-layer neural network architecture, can successfully be trained on sequence ensembles from single rounds of SELEX experiments for thrombin aptamers. RBMs assign scores to sequences that can be directly related to their fitnesses estimated through experimental enrichment ratios. Hence, RBMs trained from sequence data at a given round can be used to predict the effects of selection at later rounds. Moreover, the parameters of the trained RBMs are interpretable and identify functional features contributing most to sequence fitness. To exploit the generative capabilities of RBMs, we introduce two different training protocols: one taking into account sequence counts, capable of identifying the few best binders, and another based on unique sequences only, generating more diverse binders. We then use RBMs model to generate novel aptamers with putative disruptive mutations or good binding properties, and validate the generated sequences with gel shift assay experiments. Finally, we compare the RBM’s performance with different supervised learning approaches that include random forests and several deep neural network architectures. We show that two-layer neural networks, Restricted Boltzmann Machines (RBM), can be successfully trained on sequence ensemble datasets from selection-amplification experiments. We train the RBM using datasets from aptamer selection experiments on thrombin protein, and show that the model can successfully generalize to the test set to predict binders and non-binders. The log-likelihood assigned to a sequence by the RBM is correlated with the sequence fitness as quantified by the amplification between different rounds of selection. We further show that that the model is interpretable and by inspecting the weights of the model, we can identify structural motifs that are characteristic of the good binders. We explore the usage of the RBMs to identify which of the possible protein exosites the aptamers bind to. We show that the RBM can also be used for unsupervised clustering. Finally, we use RBMs to generate novel aptamers, and we experimentally verify predicted binding and non-binding sequences generated from the RBM.
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Affiliation(s)
- Andrea Di Gioacchino
- Laboratoire de Physique de l’Ecole Normale Supérieure, PSL & CNRS UMR8063, Sorbonne Université, Université de Paris, Paris, France
| | - Jonah Procyk
- School of Molecular Sciences and Center for Molecular Design and Biomimetics, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Marco Molari
- Laboratoire de Physique de l’Ecole Normale Supérieure, PSL & CNRS UMR8063, Sorbonne Université, Université de Paris, Paris, France
- Biozentrum, University of Basel, Basel, Switzerland
- Swiss Institute of Bioinformatics, Basel, Switzerland
| | - John S. Schreck
- National Center for Atmospheric Research, Computational and Information Systems Laboratory, Boulder, Colorado, United States of America
| | - Yu Zhou
- School of Molecular Sciences and Center for Molecular Design and Biomimetics, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Yan Liu
- School of Molecular Sciences and Center for Molecular Design and Biomimetics, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Rémi Monasson
- Laboratoire de Physique de l’Ecole Normale Supérieure, PSL & CNRS UMR8063, Sorbonne Université, Université de Paris, Paris, France
- * E-mail: (RM); (SC); (PŠ)
| | - Simona Cocco
- Laboratoire de Physique de l’Ecole Normale Supérieure, PSL & CNRS UMR8063, Sorbonne Université, Université de Paris, Paris, France
- * E-mail: (RM); (SC); (PŠ)
| | - Petr Šulc
- School of Molecular Sciences and Center for Molecular Design and Biomimetics, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- * E-mail: (RM); (SC); (PŠ)
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