An official website of the United States government
Abstract Intimately connected to the rule of life, chirality remains a long-time fascination in biology, chemistry, physics and materials science. Chiral structures, e.g., nucleic acid and cholesteric phase developed from chiral molecules are common in nature and synthetic soft materials. While it was recently discovered that achiral but bent-core mesogens can also form chiral helices, the assembly of chiral microstructures from achiral polymers has rarely been explored. Here, we reveal chiral emergence from achiral conjugated polymers, in which hierarchical helical structures are developed through a multistep assembly pathway. Upon increasing concentration beyond a threshold volume fraction, dispersed polymer nanofibers form lyotropic liquid crystalline (LC) mesophases with complex, chiral morphologies. Combining imaging, X-ray and spectroscopy techniques with molecular simulations, we demonstrate that this structural evolution arises from torsional polymer molecules which induce multiscale helical assembly, progressing from nano- to micron scale helical structures as the solution concentration increases. This study unveils a previously unknown complex state of matter for conjugated polymers that can pave way to a field of chiral (opto)electronics. We anticipate that hierarchical chiral helical structures can profoundly impact how conjugated polymers interact with light, transport charges, and transduce signals from biomolecular interactions and even give rise to properties unimagined before.
more »
« less
Herman F. Mark: Pioneer in structural chemistry, molecular biology, and polymer science
Herman Francis Mark produced brilliant contributions to the fields of organic chemistry, structural chemistry, molecular biology, and polymer science in academia and in industry in four different countries from two continents. This Legacy article outlines the author’s view on how Mark, who was universally known as the father of polymer science, also pioneered the science, education, publishing, and lecturing styles for the fields of structural chemistry and molecular biology with his disciplined and elegant leadership.
more »
« less
- Award ID(s):
- 2104554
- PAR ID:
- 10523920
- Publisher / Repository:
- Cell Press
- Date Published:
- Journal Name:
- Chem
- Volume:
- 9
- Issue:
- 12
- ISSN:
- 2451-9294
- Page Range / eLocation ID:
- 3386 to 3393
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Jason Telford, Maryville University (Ed.)Molecular visualization and structure-function discussions present a valuable lens for research, practice, and education in chemistry and biology. Currently, molecular structural data, visualization tools and resources are underutilized by students and faculty. A new community, Molecular CaseNet, is engaging undergraduate educators in chemistry and biology to collaboratively develop case studies for interdisciplinary learning on real world topics. Use of molecular case studies will help biologists focus on chemical (covalent and non-covalent) interactions underlying biological processes/cellular events and help chemists consider biological contexts of chemical reactions. Experiences in developing and using molecular case studies will help uncover current challenges in discussing biological/chemical phenomena at the atomic level. These insights can guide future development of necessary scaffolds for exploring molecular structures and linked bioinformatics resources.more » « less
-
Fankhauser, Sarah (Ed.)ABSTRACT This integrative literature review analyzes the corpus of biology education research published in the main biology education journals of major professional societies. The goal of this analysis is to determine which approaches (including groups of focus, research methods, and settings/perspectives) from social science fields (i.e., psychology, sociology, and anthropology) are utilized in published peer-reviewed biology education research relating to diversity, equity, and inclusion (DEI). Scoping how social science approaches are used in this area is important to understanding whether biology education research could benefit from complementary approaches that might advance praxis. This analysis found that research informing the biology education community draws heavily from psychological perspectives that are overwhelmingly not disaggregated (78% of articles identifying a group lumped the participant together), are by far more quantitative (58% used survey, 26% grades, 20% school data) than qualitative (17% used interview, 10% observation), and did not adopt structural approaches (72%). The addition of missing contributions from social science is critical to advancing interventions to broaden STEM participation, given that merging paradigms can offer more robust, multi-level explanations for observed phenomena. This has important implications for education, biology education, biology education research, social science, and research in related STEM fields.more » « less
-
DeePMD-kit is a powerful open-source software package that facilitates molecular dynamics simulations using machine learning potentials known as Deep Potential (DP) models. This package, which was released in 2017, has been widely used in the fields of physics, chemistry, biology, and material science for studying atomistic systems. The current version of DeePMD-kit offers numerous advanced features, such as DeepPot-SE, attention-based and hybrid descriptors, the ability to fit tensile properties, type embedding, model deviation, DP-range correction, DP long range, graphics processing unit support for customized operators, model compression, non-von Neumann molecular dynamics, and improved usability, including documentation, compiled binary packages, graphical user interfaces, and application programming interfaces. This article presents an overview of the current major version of the DeePMD-kit package, highlighting its features and technical details. Additionally, this article presents a comprehensive procedure for conducting molecular dynamics as a representative application, benchmarks the accuracy and efficiency of different models, and discusses ongoing developments.more » « less
-
We report the results of the COVID Moonshot, a fully open-science, crowdsourced, and structure-enabled drug discovery campaign targeting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease. We discovered a noncovalent, nonpeptidic inhibitor scaffold with lead-like properties that is differentiated from current main protease inhibitors. Our approach leveraged crowdsourcing, machine learning, exascale molecular simulations, and high-throughput structural biology and chemistry. We generated a detailed map of the structural plasticity of the SARS-CoV-2 main protease, extensive structure-activity relationships for multiple chemotypes, and a wealth of biochemical activity data. All compound designs (>18,000 designs), crystallographic data (>490 ligand-bound x-ray structures), assay data (>10,000 measurements), and synthesized molecules (>2400 compounds) for this campaign were shared rapidly and openly, creating a rich, open, and intellectual property–free knowledge base for future anticoronavirus drug discovery.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/j.chempr.2023.10.021
