CONTROLLING THE 3D NANOSCALE ORGANIZATION OF BULK HETEROJUNCTION POLYMER SOLAR CELLS

In this study,the three dimensional nanoscale organization in the photoactive layers of poly(3-hexylthiophene) (P3HT) and a methanofullerene derivative (PCBM) is revealed by transmission electron tomography.After annealing treatment,either at elevated temperature or during slow solvent evaporation,nanoscale interpenetrating networks are formed with high crystalline order and favorable concentration gradients of both components through the thickness of the photoactive layer.Such a tailored morphology acco...     

The ferromagnetic to paramagnetic phase transition of Fe studied by x-ray photoelectron spectroscopy

Valence band x-ray photoelectron spectra from Fe(100) have been measured as a function of temperature to above the Curie temperature, T_c. The room temperature data can be reconciled with the theoretical one-particle density of states (DOS). At T = 1.034T_c, the data do not resemble the paramgnetic DOS of Fe as calculated in the disordered-local-moment limit.     

Scaffold proteins and the regeneration of visual pigments

CRALBP, cellular retinaldehyde-binding protein, is a retinoid-binding protein necessary for efficient regeneration of rod and cone visual pigments. The C terminus of CRALBP binds to the PDZ domains of EBP50/NHERF-1, which in turn bind to ezrin and actin, proteins localized to the apical processes of the retinal pigment epithelium. In this study, we examined structural features associated with the interaction of the two proteins. The C-terminal amino-acid sequence of 11 orthologous CRALBPs is either ENTAL, ENTAF or EDTAL. Peptides ending in each of these sequences inhibited the interaction of CRALBP and EBP50/NHERF-1 with the use of an overlay assay. Molecular modeling showed that both NTAL and NTAF formed similar networks of H bonds with PDZ1 of EBP50/ NHERF-1, and the side chains of both C-terminal Leu and Phe fit into the peptide-binding groove of PDZ1x CRALBP.11-cis-retinal and EBP50/NHERF-1 migrated as single components when analyzed individually by gel filtration and as a complex when mixed together before gel filtration. Complex formation was abolished by preincubation of EBP50/NHERF-1 with peptide EVENTAL. The ligand absorption spectrum of the complex was identical with that of CRALBP x 11-cis-retinal, demonstrating that complex formation did not perturb the ligand-binding domain of CRALBP.     

Versatile and Efficient Site‐Specific Protein Functionalization by Tubulin Tyrosine Ligase

A novel chemoenzymatic approach for simple and fast site‐specific protein labeling is reported. Recombinant tubulin tyrosine ligase (TTL) was repurposed to attach various unnatural tyrosine derivatives as small bioorthogonal handles to proteins containing a short tubulin‐derived recognition sequence (Tub‐tag). This novel strategy enables a broad range of high‐yielding and fast chemoselective C‐terminal protein modifications on isolated proteins or in cell lysates for applications in biochemistry, cell biology, and beyond, as demonstrated by the site‐specific labeling of nanobodies, GFP, and ubiquitin.