Nanosecond pump-probe device for time-resolved serial femtosecond crystallography developed at SACLA.

X-ray free-electron lasers (XFELs) have opened new opportunities for time-resolved X-ray crystallography. Here a nanosecond optical-pump XFEL-probe device developed for time-resolved serial femtosecond crystallography (TR-SFX) studies of photo-induced reactions in proteins at the SPring-8 Angstrom Compact free-electron LAser (SACLA) is reported. The optical-fiber-based system is a good choice for a quick setup in a limited beam time and allows pump illumination from two directions to achieve high excitation efficiency of protein microcrystals.

Trierixin, a novel Inhibitor of ER stress-induced XBP1 activation from Streptomyces sp. II. structure elucidation.

Trierixin, a new member of the triene-ansamycin group, has been isolated from the fermentation broth of Streptomyces sp. AC654 as an inhibitor of ER stress-induced XBP1 activation. The structure of trierixin was determined on the basis of its spectroscopical and chemical properties.

The carbonic anhydrase domain protein nacrein is expressed in the epithelial cells of the mantle and acts as a negative regulator in calcification in the mollusc Pinctada fucata.

Signals and organic matrix proteins secreted from the mantle are critical for the development of shells in molluscs. Nacrein, which is composed of a carbonic anhydrase domain and a Gly-X-Asn repeat domain, is one of the organic matrix proteins that accumulates in shells. In situ hybridization revealed that nacrein was expressed in the outer epithelial cells of the mantle of the pearl oyster Pinctada fucata.

Binding mode of TMC-95A analogues to eukaryotic 20S proteasome.

The complex thermodynamics that govern noncovalent protein-ligand interactions are still not fully understood, despite the exponential increase in experimental structural data available from X-ray crystallography and NMR spectroscopy. The eukaryotic 20S proteasome offers an ideal system for such studies as it contains in duplicate three proteolytically active sites with different substrate specificities. The natural product TMC-95A inhibits these proteolytic centers noncovalently with distinct affinities.

TMC-256A1 and C1, new inhibitors of IL-4 signal transduction produced by Aspergillus niger var niger TC 1629.

New inhibitors of IL-4 signal transduction, designated as TMC-256A1 and C1, were discovered together with TMC-256B1, a previously known dihydronaphthopyrone, from the fermentation broth of Aspergillus niger var niger TC 1629 by using an IL-4 driven reporter gene assay. Based on spectroscopic analyses, TMC-256A1 and C1 were found to be new members of the naphthopyrone antibiotics. TMC-256A1, B1 and C1 inhibited the IL-4 driven luciferase activity with IC50 values of 25 microM, 30 microM and 1.