Phenotypic characterization of CO2-requiring strains of Streptococcus bovis from koalas.

We examined phenotypic characteristics of six mannitol-fermenting strains of Streptococcus bovis, including two unusual CO2-requiring strains isolated from koala feces. These strains did not grow in air, but grew in air supplemented with CO2 and under reduced oxygen conditions. All six strains had the same biochemical characteristics, except that the CO2-requiring strains did not produce beta-N-acetylglucosaminidase.     

Synthesis and evaluation of bromoacetoxy 4-androsten-3-ones as active site-directed inhibitors of human placental aromatase

2 alpha-Bromoacetoxy (II), 6-bromoacetoxy (VII and X), and 19-bromoacetoxy (XII) derivatives of androstenedione and 17 beta-bromoacetoxy compounds (III, IV, XIII-XVI) were synthesized as potential affinity-labeling reagents for aromatase. 6 alpha-Bromoacetoxy derivative VII was the most potent inhibitor of human placental microsomal aromatase activity among this series. Its inhibitory activity was higher than that of the parent 6 alpha-hydroxy compound V, although other bromoacetates showed weaker inhibition of aromatase than the corresponding alcohols. The bromoacetates (except the 6 beta-bromoacetate X) inhibited aromatase activity in a time-dependent manner in the absence of NADPH, and the enzyme inactivation was blocked by the addition of androstenedione to the incubates. Kinetic analysis of the time- and concentration-dependent inhibition by the 6 beta-bromo-17 beta-bromoacetoxy compound XV gave an apparent Ki of 25 microM and kinact of 0.027 min-1.     

Mammal assemblages recorded by camera traps inside and outside the evacuation zone of the Fukushima Daiichi Nuclear Power Plant accident

In 2011, the Fukushima Daiichi Power Plant accident resulted in the evacuation of about 81,000 people from the evacuation zone, which suffered from high levels of radioactive contamination. Large-scale and long-term land abandonment can cause changes in species assemblages. Despite the extensive global attention this incident received, open and spatially-explicit datasets of mammal fauna from Fukushima remain quite limited. We established a continuous monitoring protocol using camera traps for mammals both inside and outside the evacuation zone; this paper presents our first dataset. These data represent the monitoring results from 45 camera traps from May 2014 to October 2014, including the location and actuation time of each camera, and the list of video records. After the publication of this initial data paper, we intend to continue monitoring until 2023 and the dataset will be hereafter updated with new observations.     

FtsZ in Bacterial Cytokinesis: Cytoskeleton and Force Generator All in One

Summary: FtsZ, a bacterial homolog of tubulin, is well established as forming the cytoskeletal framework for the cytokinetic ring. Recent work has shown that purified FtsZ, in the absence of any other division proteins, can assemble Z rings when incorporated inside tubular liposomes. Moreover, these artificial Z rings can generate a constriction force, demonstrating that FtsZ is its own force generator. Here we review light microscope observations of how Z rings assemble in bacteria. Assembly begins with long-pitch helices that condense into the Z ring. Once formed, the Z ring can transition to short-pitch helices that are suggestive of its structure. FtsZ assembles in vitro into short protofilaments that are ∼30 subunits long. We present models for how these protofilaments might be further assembled into the Z ring. We discuss recent experiments on assembly dynamics of FtsZ in vitro, with particular attention to how two regulatory proteins, SulA and MinC, inhibit assembly. Recent efforts to develop antibacterial drugs that target FtsZ are reviewed. Finally, we discuss evidence of how FtsZ generates a constriction force: by protofilament bending into a curved conformation.     

Macrophage migration inhibitory factor (MIF) produced by a human T cell hybridoma clone

A human T cell hybridoma clone, F5, producing high levels of macrophage migration inhibitory factor (MIF) was established by the emetine-actinomycin D selection method. This clone produced two species of MIF which were separated on a Phenyl Sepharose column. We purified MIF-2 (the more hydrophobic species of the two) to homogeneity from the conditioned medium of stimulated F5 cells by a series of steps that included hydrophobic chromatography, ion-exchange chromatography. Ricinus communis lectin affinity chromatography, and high-performance liquid chromatography on anion exchange and reverse-phase columns. Purified MIF was digested with endoproteinase Lys-C and Asp-N. The amino acid sequences of the generated peptides were determined. No sequence similarity with any other protein was found. The molecular weight of MIF-2 was estimated to be 45 kDa from sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of immunoprecipitates with anti-peptide antibodies. These results show that F5MIF-2 is a novel cytokine.     

Structure-activity studies of non-steroidal aromatase inhibitors: the crystal and molecular structures of CGS 16949A and CGS 18320B.

The crystal and molecular structures of 4-(5,6,7,8-tetrahydroimidazo[1,5-a]pyridin-5-yl)benzonitrile hydrochloride (CGS 16949A) and bis(p-cyanophenyl)imidazo-1-yl methane hemisuccinate (CGS 18320B) have been determined as part of structure-activity relationship studies of non-steroidal aromatase inhibitors. CGS 18320B crystallizes with two inhibitor molecules in the asymmetric unit that are similar in conformation. The cyanophenyl groups and the imidazole moieties in the CGS 18320B molecules display a propellor-like arrangement. The orientation of the imidazole ring in CGS 16949A, which is constrained by the piperidine ring, differs by about 80 degrees from the orientations in both CGS 18320B molecules. The conformations of both compounds are consistent with the proposed model (Banting et al. (1988) J. Enz. Inhibit., 2, 216) for inhibitor binding by positioning of the cyanophenyl group in the steroid A-ring binding site and interaction of the imidazole nitrogen with the iron of the haem.