Volume 5 Issue 7, July 2013

Volume 5 Issue 7

The extent to which protein motions can affect the chemical step of an enzymatic reaction has caused heated debate in recent times. Now, J. Javier Ruiz-Pernía, Iñaki Tuñón and colleagues describe how free-energy surfaces obtained as a function of both a chemical coordinate and an environmental coordinate can be used to explore the role of structure and motion on enzyme chemistry. They studied an SN2 nucleophilic reaction catalysed by a haloalkane dehalogenase from Xanthobacter autotrophicus; the enzyme is schematically represented on the cover.Article p566IMAGE: CARLOS GARCIA-MESEGUERCOVER DESIGN: ALEX WING

Thesis

  • Thesis |

    Chemical compounds are often taken for granted, argues Bruce Gibb, and the most underappreciated is one that we're all very familiar with.

    • Bruce C. Gibb

Research Highlights

Blogroll

News and Views

  • News & Views |

    Radiation of sufficient energy can knock out a tightly bound core-electron from the inner shell of a water molecule, leaving behind a short-lived, highly excited state. Now, through electron spectroscopy and theoretical simulations, these states have been observed to undergo previously unconsidered proton-mediated processes in solution.

    • Lars G. M. Pettersson
  • News & Views |

    A simple method to investigate the functional group compatibility and scope of new reaction methodology could improve the speed with which it is adopted by end-users, and have benefits in many related areas of chemical research.

    • Ian Churcher
  • News & Views |

    For more than a decade, single-molecule magnets have relied on multinuclear transition metal clusters and lanthanide compounds. Now, a mononuclear, two-coordinate iron(I) complex has shown that single transition metals can compete with the lanthanides when certain design principles from magnetochemistry are borne in mind.

    • Eckhard Bill
  • News & Views |

    Protein drugs are important therapies for many different diseases, but very few can be administered orally. Now, a cationic dendronized polymer has been shown to stabilize a therapeutic protein for delivery to the gut.

    • Heather D. Maynard

Perspective

  • Perspective |

    The reduction of N2 by iron and molybdenum complexes is a rapidly moving field. This Perspective discusses the key advances in the past two years. The recent discovery of carbide at the centre of the iron-molybdenum cofactor of nitrogenase is also described, along with the most compelling areas for continued research.

    • K. Cory MacLeod
    •  & Patrick L. Holland

Articles

  • Article |

    The influence of protein motions on the chemical step of enzyme reactions is a contentious issue. Now, by constructing free-energy surfaces using an explicit solvent coordinate, it is shown that, although some structural flexibility is required, protein motions can be described as equilibrium fluctuations.

    • Rafael García-Meseguer
    • , Sergio Martí
    • , J. Javier Ruiz-Pernía
    • , Vicent Moliner
    •  & Iñaki Tuñón
  • Article |

    Carbon nanotubes (CNTs) are typically produced as a mixture of tubes with different diameters and sidewall structures — parameters that determine the optical and electronic properties of these materials. Now, it has been shown that discrete carbon nanorings can be used as templates to control the bottom-up growth of CNTs with a narrow distribution of diameters.

    • Haruka Omachi
    • , Takuya Nakayama
    • , Eri Takahashi
    • , Yasutomo Segawa
    •  & Kenichiro Itami
  • Article |

    Mononuclear complexes of certain lanthanide ions are known to have large magnetization reversal barriers caused by strong spin–orbit coupling. Now, careful tuning of the ligand field of a transition metal complex has engendered a comparable spin-reversal barrier — and in turn magnetic blocking at 4.5 K.

    • Joseph M. Zadrozny
    • , Dianne J. Xiao
    • , Mihail Atanasov
    • , Gary J. Long
    • , Fernande Grandjean
    • , Frank Neese
    •  & Jeffrey R. Long
  • Article |

    Methods for stabilizing enzymatic activity in the gastrointestinal tract are rarely investigated because of the difficulty in protecting proteins from an environment that promotes their digestion. Now, functionally diverse polymers have been conjugated to therapeutic enzymes, which lead to a substantial enhancement of their in vivo activity in the gastrointestinal tract.

    • Gregor Fuhrmann
    • , Andrea Grotzky
    • , Ružica Lukić
    • , Simon Matoori
    • , Paola Luciani
    • , Hao Yu
    • , Baozhong Zhang
    • , Peter Walde
    • , A. Dieter Schlüter
    • , Marc A. Gauthier
    •  & Jean-Christophe Leroux
  • Article |

    Previously unobserved types of reactive species formed on the core ionization of liquid water have been identified using a combination of liquid microjet photoemission spectroscopy and ab initio calculations. The charge-separated di-cationic species are formed within a few femtoseconds, through proton-transfer-mediated processes followed by autoionization.

    • Stephan Thürmer
    • , Milan Ončák
    • , Niklas Ottosson
    • , Robert Seidel
    • , Uwe Hergenhahn
    • , Stephen E. Bradforth
    • , Petr Slavíček
    •  & Bernd Winter
  • Article |

    For researchers to rapidly adopt new synthetic methodology, they need to gauge whether the reaction will work for their substrate — a point not easily conveyed by traditional screens of reaction scope. Here, a simple method is described to assess the likely scope and limitations of a chemical reaction beyond the idealized conditions initially reported.

    • Karl D. Collins
    •  & Frank Glorius
  • Article |

    The average single-nanocrystal spectral linewidth within an ensemble of nanocrystal emitters in solution can be directly and quantitatively measured using photon-correlation Fourier spectroscopy (S-PCFS). Variations in single-nanocrystal linewidths between batches are found to be significant and synthetically tunable, introducing new avenues for the optimization of nanocrystals for optical applications.

    • Jian Cui
    • , Andrew P. Beyler
    • , Lisa F. Marshall
    • , Ou Chen
    • , Daniel K. Harris
    • , Darcy D. Wanger
    • , Xavier Brokmann
    •  & Moungi G. Bawendi
  • Article |

    A tubular assembly based on barrel-shaped chaperonin protein mutants, held together through coordination to magnesium ions, has been devised that carries and delivers guests into cells. The hydrolysis of ATP — present in much higher concentration inside the cell than outside — induces a conformational change in chaperonin that in turn triggers the guest release.

    • Shuvendu Biswas
    • , Kazushi Kinbara
    • , Tatsuya Niwa
    • , Hideki Taguchi
    • , Noriyuki Ishii
    • , Sumiyo Watanabe
    • , Kanjiro Miyata
    • , Kazunori Kataoka
    •  & Takuzo Aida
  • Article |

    A scanning tunnelling microscope has been used to image multistep chemical reactions at a solid/liquid interface with single-molecule resolution. On reacting Mn(III) porphyrins with either O2 or a single oxygen donor, at least four distinct reaction intermediates and products were detected and their interconversion could be observed in real space and real time.

    • Duncan den Boer
    • , Min Li
    • , Thomas Habets
    • , Patrizia Iavicoli
    • , Alan E. Rowan
    • , Roeland J. M. Nolte
    • , Sylvia Speller
    • , David B. Amabilino
    • , Steven De Feyter
    •  & Johannes A. A. W. Elemans
  • Article |

    The disassembly of a parent zeolite and its reassembly into two zeolites with targeted topologies is described. This process demonstrates that it is possible to target specific ring sizes in a zeolite by replacing one size of unit in the structure with alternative units of a different size.

    • Wieslaw J. Roth
    • , Petr Nachtigall
    • , Russell E. Morris
    • , Paul S. Wheatley
    • , Valerie R. Seymour
    • , Sharon E. Ashbrook
    • , Pavla Chlubná
    • , Lukáš Grajciar
    • , Miroslav Položij
    • , Arnošt Zukal
    • , Oleksiy Shvets
    •  & Jiří Čejka

In Your Element

  • In Your Element |

    The chemistry of element 114 seems to be in reach, yet Peter Schwerdtfeger cautions that we should expect the unexpected from this young element, which is so different to its lighter counterparts.

    • Peter Schwerdtfeger

Corrigenda