Volume 8 Issue 5, May 2016

Volume 8 Issue 5

Frances H. Arnold, Vijay S. Pande and co-workers show, using large-scale molecular dynamics simulations, that the flexible F/G loop of a nitrating cytochrome P450 enzyme transitions between a set of disordered open-lid conformations and a set of structured closed-lid conformations. In the closed-lid conformations, the His176 residue engages in a direct interaction with the l-tryptophan substrate. A single mutation at this position not only controls loop dynamics but also, surprisingly, switches the regioselectivity of the nitration reaction.Article p419IMAGE: SHEEL DODANI AND GERT KISSCOVER DESIGN: KAREN MOORE

Commentary

  • Commentary |

    The practice and overarching mission of chemistry need a major overhaul in order to be fit for purpose in the twenty-first century and beyond. The concept of 'one-world' chemistry takes a systems approach that brings together many factors, including ethics and sustainability, that are critical to the future role of chemistry.

    • Stephen A. Matlin
    • , Goverdhan Mehta
    • , Henning Hopf
    •  & Alain Krief

Thesis

  • Thesis |

    A trio of recent discoveries in physics should be celebrated by everyone, even chemists, argues Bruce Gibb.

    • Bruce C. Gibb

News and Views

  • News & Views |

    Understanding the minute details of CO2 transport is key to finding new technologies that reduce the hazardous levels of CO2 in our atmosphere. Now, the observation that the transport of CO2 in molten calcium carbonate occurs faster than standard molecular diffusion brings us one step closer.

    • Barbara Kirchner
    •  & Barbara Intemann
  • News & Views |

    A fundamental challenge in systems chemistry is to engineer the emergence of complex behaviour. The collective structures of metal cyanide chains have now been interpreted in the same manner as the myriad of magnetic phases displayed by frustrated spin systems, highlighting a symbiotic approach between systems chemistry and magnetism.

    • Lucy Clark
    •  & Philip Lightfoot
  • News & Views |

    A chiral [2]rotaxane in which the asymmetry is derived from the way in which the two components are mechanically interlocked — rather than being encoded in the covalent connectivity of the components themselves — has been shown to act as an enantioselective organocatalyst.

    • Stephen M. Goldup

Review

  • Review Article |

    Chemical protein synthesis can enable the preparation of proteins containing post-translational modifications or unnatural variations such as D-amino acids. Such modified proteins are not easily fabricated by other methods. This Review provides an overview of the current approaches for the chemical synthesis of proteins.

    • Somasekhar Bondalapati
    • , Muhammad Jbara
    •  & Ashraf Brik

Articles

  • Article |

    A collaborative approach between experiment and simulation has revealed a single mutation in the F/G loop of the newly described nitrating cytochrome P450 TxtE that controls loop dynamics and, more surprisingly, the regioselectivity of the reaction. This mutation is present in a subset of homologous nitrating P450s that produce a previously unidentified biosynthetic intermediate, 5-nitro-L-tryptophan.

    • Sheel C. Dodani
    • , Gert Kiss
    • , Jackson K. B. Cahn
    • , Ye Su
    • , Vijay S. Pande
    •  & Frances H. Arnold
  • Article |

    Li+-selective solid electrolytes may enable next-generation battery systems, such as Li–S and Li–O2. Now, in an exemplar system, it is shown that a resistive interphase forms at the interface between solid and liquid electrolytes, termed the solid-liquid electrolyte interphase (SLEI). An in situ study of this undesirable effect is supported by state-of-the-art surface analysis.

    • Martin R. Busche
    • , Thomas Drossel
    • , Thomas Leichtweiss
    • , Dominik A. Weber
    • , Mareike Falk
    • , Meike Schneider
    • , Maria-Louisa Reich
    • , Heino Sommer
    • , Philipp Adelhelm
    •  & Jürgen Janek
  • Article |

    Endohedral C70 fullerenes containing either one or two water molecules have now been prepared using a molecular-surgery approach. The structure of H2O@C70 was determined by single-crystal X-ray analysis, revealing the encapsulated water molecule to be in an off-centre position. In (H2O)2@C70, the two water molecules form a discrete dimer held together with a single hydrogen bond.

    • Rui Zhang
    • , Michihisa Murata
    • , Tomoko Aharen
    • , Atsushi Wakamiya
    • , Takafumi Shimoaka
    • , Takeshi Hasegawa
    •  & Yasujiro Murata
  • Article |

    Competing metallophilic and electrostatic interactions between gold and/or silver cyanide chains govern their assembly into different structures. An analogy has now been drawn between these systems and two-dimensional magnets. Supramolecular interactions between the chains have been tuned to mimic different magnetic interactions, leading to the realization of complex states predicted for magnets.

    • Andrew B. Cairns
    • , Matthew J. Cliffe
    • , Joseph A. M. Paddison
    • , Dominik Daisenberger
    • , Matthew G. Tucker
    • , François-Xavier Coudert
    •  & Andrew L. Goodwin
  • Article |

    The development of cells requires a mechanism to support homeostasis—the maintenance of constant internal conditions—as cellular growth results in internal dilution. Now, a simple physical process is described in which short oligonucleotide inhibitors enable dilution-driven activation of encapsulated ribozymes via membrane growth, suggesting homeostatic mechanisms could have existed in the earliest cells.

    • Aaron E. Engelhart
    • , Katarzyna P. Adamala
    •  & Jack W. Szostak
  • Article |

    The solvation behaviour of CO2 in carbonate melts is important from both a geochemical point of view and with respect to its electroreduction. Now, simulations have shown that solvation of CO2 in molten CaCO3 leads to the formation of the pyrocarbonate anion, C2O52–, which significantly enhances the transport of CO2 via a Grotthuss-like mechanism.

    • Dario Corradini
    • , François-Xavier Coudert
    •  & Rodolphe Vuilleumier
  • Article |

    Capsular polysaccharides are a protective layer enveloping pathogenic bacteria. Understanding their export could guide the design of therapeutics that render bacteria vulnerable to attack by the immune system or other therapeutic agents. Now, a synthetic strategy of polyglycosylation has been developed to obtain defined capsular polysaccharide fragments. Subsequent nanolitre detection enables their export to be studied at the single-molecule level.

    • Lingbing Kong
    • , Andrew Almond
    • , Hagan Bayley
    •  & Benjamin G. Davis
  • Article |

    Controlling the morphology and composition of hybrid nanostructures is desirable for applications, but it has proven challenging to precisely combine different nucleation sites and growth modes. Now, three types of hierarchical 1D/2D nanostructures have been prepared by selectively growing semiconductor nanorod arrays (CdS or CdSe) on the different facets of hexagonal nanoplates.

    • Xue-Jun Wu
    • , Junze Chen
    • , Chaoliang Tan
    • , Yihan Zhu
    • , Yu Han
    •  & Hua Zhang
  • Article |

    Precise control of vesicle size is highly desirable both for basic biochemical research and biomedical applications. Now, monodispersed sub-100-nm vesicles with predefined sizes have been produced using a method based on membrane self-assembly within a DNA-nanostructure guide.

    • Yang Yang
    • , Jing Wang
    • , Hideki Shigematsu
    • , Weiming Xu
    • , William M. Shih
    • , James E. Rothman
    •  & Chenxiang Lin
  • Article |

    Understanding the correlation between structure and charge transport properties of a DNA-based single molecule device is crucial to the creation of nanoscale functional devices. Now, a DNA-based molecular rectifier with a high rectification ratio has been constructed by site-specific intercalation of small molecules (coralyne) into native double-stranded DNA.

    • Cunlan Guo
    • , Kun Wang
    • , Elinor Zerah-Harush
    • , Joseph Hamill
    • , Bin Wang
    • , Yonatan Dubi
    •  & Bingqian Xu
  • Article |

    L-Cysteine-derived thiazolidines have now been shown to be artificial substrates of the radical SAM enzyme HydE, which converts them into S-adenosyl-L-cysteine. Carbon–sulfur bonds are formed in a concerted mechanism that involves the formation of a C-centred radical that concomitantly attacks the S atom of a thioether. This is the first example of a radical SAM enzyme that reacts directly on a sulfur atom instead of abstracting an H-atom.

    • Roman Rohac
    • , Patricia Amara
    • , Alhosna Benjdia
    • , Lydie Martin
    • , Pauline Ruffié
    • , Adrien Favier
    • , Olivier Berteau
    • , Jean-Marie Mouesca
    • , Juan C. Fontecilla-Camps
    •  & Yvain Nicolet
  • Article |

    Phase transitions in materials are intriguing, and can also be of practical importance. Below 150 K, mixed-valent iron oxide Fe4O5 has now been shown to undergo an unusual charge-ordering phase transition that involves the competing formation of iron dimers and trimers, and leads to a significant increase in electrical resistivity.

    • Sergey V. Ovsyannikov
    • , Maxim Bykov
    • , Elena Bykova
    • , Denis P. Kozlenko
    • , Alexander A. Tsirlin
    • , Alexander E. Karkin
    • , Vladimir V. Shchennikov
    • , Sergey E. Kichanov
    • , Huiyang Gou
    • , Artem M. Abakumov
    • , Ricardo Egoavil
    • , Johan Verbeeck
    • , Catherine McCammon
    • , Vadim Dyadkin
    • , Dmitry Chernyshov
    • , Sander van Smaalen
    •  & Leonid S. Dubrovinsky
  • Article |

    An important source of atmospheric hydroxyl radicals is from the dissociation of Criegee intermediates produced in alkene ozonolysis reactions. The dissociation dynamics of the prototypical CH3CHOO Criegee intermediate have now been determined. Complementary experimental and theoretical studies were carried out and the translational and internal energy distributions of the OH radical products were characterized.

    • Nathanael M. Kidwell
    • , Hongwei Li
    • , Xiaohong Wang
    • , Joel M. Bowman
    •  & Marsha I. Lester

In Your Element

  • In Your Element |

    From secretive beginnings to serving in missions on Mars, Rebecca J. Abergel and Eric Ansoborlo take a look at the glowing mark curium has left on contemporary science and technology.

    • Rebecca J. Abergel
    •  & Eric Ansoborlo