No abstract

Tunable dye laser excitation of carefully prepared samples of Rb. sphaeroides reaction centers provides richly detailed resonance Raman (RR) spectra of the bacteriopheophytins, H, and the accessory bacteriochlorophylls, B. These spectra demonstrate selective enhancement of the separate bacteriopheophytins on the active (H(L)) and inactive (H(M)) sides of the reaction centers. The spectra are assigned with the aid of normal coordinate analyses using force fields previously developed for porphyrins and reduced porphyrins. Comparison of the H(L) and H(M) vibrational mode frequencies reveals evidence for greater polarization of the acetyl substituent in H(L) than H(M). This polarization is expected to make H(L) easier to reduce, thereby contributing to the directionality of electron transfer from the special pair, P. In addition, the acetyl polarization of H(L) is increased at low temperature (100 K), helping to account for the increase in electron transfer rate. The polarizing field is suggested to arise from the Mg(2+) of the neighboring accessory bacteriochlorophyll, which is 4.9 A from the acetyl O atom. The 100 K spectra show sharpening and intensification of a number of RR bands, suggesting a narrowing of the conformational distribution of chromophores, which is consistent with the reported narrowing of the distribution in electron transfer rates. Excitation at 800 nm produces high-quality RR spectra of the accessory bacteriochlorophylls, and the spectral pattern is unaltered on tuning the excitation to 810 nm in resonance with the upper exciton transition of P. Either the resonance enhancement of P is weak, or the bacteriochlorophyll RR spectra are indistinguishable for P and B.

No abstract

I thank all those referees who helped assess submissions to Journal of the Royal Society Interface (volume 13) in 2016. The editorial team very much appreciates the time and dedication given by academics to the peer review process and to recognize their efforts we list the names of all reviewers who provided reports last year (unless they have opted out or not responded). This article is made permanent and citeable by its digital object identifier (DOI). We encourage you to quote your contribution in your applications for tenure and grants or other forms of research assessment. Where you have provided it, we have included your ORCID so your contribution can be unambiguously assigned to you.

Our editorial board and publishers are delighted with the rapid rise of research interest engendered by the Journal of the Royal Society Interface from its 2004 inception. Burgeoning submissions are accompanied by a broadening range of published research that draws on physical disciplines set to decipher the complexities of natural history. To celebrate our 10th-year, we have introduced a new feature to the J. R. Soc. Interface: 'Headline Reviews'. Published as a regular part of the journal, Headline Reviews are written by preeminent researchers invited to focus attention on the most recent activities in their areas of expertise. Furthermore, to gain perspective on the topic, both in the breadth and range of opinion, several leading authors will contribute Headline Reviews on different aspects of the same field. Consequently, a number of related reviews will appear serially over several journal issues, and once a collection is completed it is will be possible to access them as a whole via the journal's website. The inaugural Headline Review, which follows this Editorial, is by Prof. James Barber FRS and Dr Phong D. Tran, entitled 'From Natural to Artificial Photosynthesis'. One method to tackle the ever-increasing demand for energy, without producing extraneous CO 2 emissions, is through solar power. However, challenges still remain as to how best this can be captured, converted and then stored. An appealing option is to mimic Nature by creating an 'artificial leaf' which can store solar energy in the form of chemical bonds as occurs in natural photosynthesis. Barber and Tran review the progress made towards achieving this goal. This contribution initiates a series of Headline Reviews on biological energy conversion; other themes will commence later in the year. We hope that readers of J. R. Soc. Interface will find this new venture of great interest.