Volume 2 Issue 11, November 2010

Volume 2 Issue 11

The barrel-like structure of the heptameric-pore-forming protein ɑ-haemolysin can be used as a 'nanoreactor' to study the reactions of single molecules. Now, Hagan Bayley and co-workers have engineered a pore in which one of the seven subunits contains a cysteine residue. The thiol side-chain of this amino acid can react with a quinone inside the pore (shown conceptually on the cover) and the ion current through the pore used to study the reaction kinetics. a deuterium-isotope effect — in a mechanistic step that occurs after the rate-determining step — has been observed for the first time.

Cover design by Alex Wing/Nature Chemistry.

Article p921

News & Views p905

Editorial

  • Editorial |

    Experimental data is the foundation on which science is built. Providing easier ways to find and search it is one way in which new online technologies can help to advance research.

Research Highlights

Blogroll

News and Views

  • News & Views |

    The dynamics of a complex chemical reaction that occurs through a well-defined intermediate have been followed at the single-molecule level using a 'nanoreactor' set-up, revealing a primary hydrogen isotope effect that is invisible to ensemble experiments.

    • Sergi Garcia-Manyes
  • News & Views |

    Hydration is known to affect molecular-recognition processes, such as those between proteins and ligands. Now, theoretical simulations provide thermodynamic insight into cavity–ligand binding, revealing how it is predominantly driven by the behaviour of the few surrounding water molecules.

    • Gerhard Hummer
  • News & Views |

    Compression of the active sites of enzymes has been linked to the bulk of amino acid side chains, but now experiments highlight that the harder we look, the more curious the relationship between protein structure and function becomes.

    • Judith P. Klinman
  • News & Views |

    Computational studies have been used to accurately model the properties of a metal–organic framework. The material, subsequently synthesized, lived up to the predicted high surface area and sorption ability.

    • George K. H. Shimizu
  • News & Views |

    Chemists have now prepared the longest known stable subunit of the elusive all-carbon polymer — carbyne. Their results suggest that carbyne itself would have a polyyne-like rather than a cumulene structure.

    • Michael M. Haley

Perspective

  • Perspective |

    When it comes to porosity, the materials that spring to mind are typically one-, two- or three-dimensional extended networks. In this Perspective, discrete organic molecules are discussed that form porous solids — either owing to hollow molecular structures or simply through inefficient packing — with different properties from those of extended networks.

    • James R. Holst
    • , Abbie Trewin
    •  & Andrew I. Cooper

Articles

  • Article |

    When anchored inside a protein pore, the bond-making and bond-breaking events of a single reacting molecule can be detected by alterations in current flow. This approach is used to detect a hydrogen–deuterium kinetic isotope effect. The single-molecule measurements provide information not available from experiments on an ensemble system.

    • Siran Lu
    • , Wen-Wu Li
    • , Dvir Rotem
    • , Ellina Mikhailova
    •  & Hagan Bayley
  • Article |

    The impact of photo-damage on natural photosynthetic systems is lessened through their autonomous self-repair, and now a synthetic photoelectrochemical complex that mimics this behaviour has been developed. It is shown that a series of regeneration steps, driven by chemical signalling, increases the photo-conversion efficiency of the system and extends its lifetime indefinitely.

    • Moon-Ho Ham
    • , Jong Hyun Choi
    • , Ardemis A. Boghossian
    • , Esther S. Jeng
    • , Rachel A. Graff
    • , Daniel A. Heller
    • , Alice C. Chang
    • , Aidas Mattis
    • , Timothy H. Bayburt
    • , Yelena V. Grinkova
    • , Adam S. Zeiger
    • , Krystyn J. Van Vliet
    • , Erik K. Hobbie
    • , Stephen G. Sligar
    • , Colin A. Wraight
    •  & Michael S. Strano
  • Article |

    A new class of stable, isolable N-silyl oxyketene imines derived from protected cyanohydrins is introduced. Utilization of these nucleophiles in Lewis-base-catalysed aldol additions allows access to either cross-benzoin or glycolate aldol-type products in good yields and exceptional selectivities by simply altering the conditions of the reaction.

    • Scott E. Denmark
    •  & Tyler W. Wilson
  • Article |

    Metal ions and organic linkers have been assembled into a wide variety of metal–organic frameworks, but tailoring the properties of these materials for specific applications by designing them from first principles has proved difficult. Now, a highly porous MOF that was first identified through computational studies has been prepared and found to exhibit excellent gas-uptake.

    • Omar K. Farha
    • , A. Özgür Yazaydın
    • , Ibrahim Eryazici
    • , Christos D. Malliakas
    • , Brad G. Hauser
    • , Mercouri G. Kanatzidis
    • , SonBinh T. Nguyen
    • , Randall Q. Snurr
    •  & Joseph T. Hupp
  • Article |

    The formation of simple prebiotic organic compounds on early Earth is thought to be an important step in the origin of life. Molecular dynamics simulations of the conditions within cometary ice during planetary impact suggest a possible mechanism for the formation of glycine, an amino acid.

    • Nir Goldman
    • , Evan J. Reed
    • , Laurence E. Fried
    • , I.-F. William Kuo
    •  & Amitesh Maiti
  • Article |

    Application of supramolecular chemistry in living systems is challenging because of the inherent chemical complexity of cellular environments. Now, the use of a carefully designed host–guest system featuring diaminohexane-terminated gold nanoparticles and complementary cucurbit[7]uril macrocycles has been shown to provide triggered activation of a therapeutic system in living cells.

    • Chaekyu Kim
    • , Sarit S. Agasti
    • , Zhengjiang Zhu
    • , Lyle Isaacs
    •  & Vincent M. Rotello
  • Article |

    The structure of the carbon allotrope ‘carbyne’ is based on a framework of sp-hybridized carbon. To model its properties, a series of conjugated polyynes — the longest of which contains 44 contiguous acetylenic carbons — have been synthesized and their spectroscopic properties investigated.

    • Wesley A. Chalifoux
    •  & Rik R. Tykwinski
  • Article |

    Processes that convert racemic chiral compounds into enantioenriched chiral products are highly sought after. Here, in a copper-catalysed borylation reaction one enantiomer of a cyclic allylic ether reacts with anti-stereoselectivity and the other reacts with syn-stereoselectivity. The starting material is not easily racemized and this new process is dubbed an enantioconvergent reaction.

    • Hajime Ito
    • , Shun Kunii
    •  & Masaya Sawamura
  • Article |

    Although ultrasonic vibrations are known to be capable of aligning macromolecules in solution, the question of whether audible sound — which has much lower frequencies — can have such an effect is somewhat controversial. Now, however, it has been shown that supramolecular nanofibres can be preferentially aligned parallel to the propagation direction of audible sound.

    • Akihiko Tsuda
    • , Yuka Nagamine
    • , Reiko Watanabe
    • , Yoshiki Nagatani
    • , Noriyuki Ishii
    •  & Takuzo Aida
  • Article |

    The design of receptors for the selective capture of F is important because of the potential toxicity of this anion. Now, a telluronium borane has been shown to form a very stable fluoride chelate complex. The stability of the complex can be correlated to the Lewis acidity of the telluronium centre.

    • Haiyan Zhao
    •  & François P. Gabbaï
  • Article |

    Nature frequently shows exquisite control over reactions both of water and in water. Here, the enantioselective conjugate addition of water to an enone — a reaction that has no equivalent in conventional homogeneous catalysis — is catalysed by a copper complex of an achiral ligand that is non-covalently bound to DNA.

    • Arnold J. Boersma
    • , David Coquière
    • , Danny Geerdink
    • , Fiora Rosati
    • , Ben L. Feringa
    •  & Gerard Roelfes

In Your Element

  • In Your Element |

    Jim Ibers talks about neptunium, an element that has remained largely unnoticed despite the flurry of activity devoted to its neighbours in the periodic table, uranium and plutonium.

    • Jim Ibers

Correction