N-Benzoyl anthranilic acid derivatives as selective inhibitors of aldo-keto reductase AKR1C3

Human aldo-keto reductases AKR1C1-AKR1C3 are involved in the biosynthesis and inactivation of steroid hormones and prostaglandins and thus represent attractive targets for the development of new drugs. We synthesized a series of N-benzoyl anthranilic acid derivatives and tested their inhibitory activity on AKR1C enzymes. Our data show that these derivatives inhibit AKR1C1-AKR1C3 isoforms with low micromolar potency. In addition, five selective inhibitors of AKR1C3 were identified. The most promising inhibitors were compounds 10 and 13, with IC(50) values of 0.31μM and 0.35μM for AKR1C3, respectively.     

Loopholes in the regulation of invasive species: genetic identifications identify mislabeling of prohibited aquarium plants

Numerous invasive aquatic species introductions can be traced to the aquarium trade. Many potentially harmful aquarium species may be difficult to identify based on morphology alone. As such, some prohibited or invasive species may be available for purchase if they are mislabeled as species without restrictions. Here we compare molecular identifications to internet vendors’ identifications for accessions of a popular genus of aquarium plants that are difficult to distinguish morphologically (Myriophyllum; watermilfoils). Specifically, we identified the extensive mislabeling of M. heterophyllum—an invasive species in the northeastern and western US. Furthermore, genotypes of M. heterophyllum found in our aquarium survey have also been found in invasive populations, suggesting their potential introduction through escape from aquaria, water gardens, or nurseries. Two additional taxa were sold under incorrect names. Finally, our survey revealed that Myriophyllum taxa present in the aquarium trade generally have poorly known distributions and ecologies, and therefore their invasive potential is unknown. Our study confirms that molecular identification methods can provide a valuable tool to survey commercial pathways for potentially harmful species that are otherwise difficult to identify.     

Practical application of different enzymes immobilized on sepabeads

The immobilization of an endoglucanase, benzoylformate decarboxylase (BFD) from Pseudomonas putida, as well as of lipase B from Candida antarctica (CALB) onto the carrier supports Sepabeads EC-EP, Sepabeads EC-EA, and Sepabeads EC-BU was accomplished. It is shown that via these immobilized biocatalysts the synthesis of both fine and bulk chemicals is possible. This is illustrated by the syntheses of polyglycerol esters and (S)-hydroxy phenyl propanone. The benefit of immobilization is illustrated by repetitive use in a bubble column reactor as well as in a stirred tank reactor. High stability of two biocatalysts was achieved and reusability up to eight times was demonstrated. The comparison of CALB immobilized on Sepabeads EC-EP to Novozym 435 shows similar activity. Dedicated to Prof. Dr. Christian Wandrey on the occasion of his 65th birthday.     

A perivascular origin for mesenchymal stem cells in multiple human organs

Mesenchymal stem cells (MSCs), the archetypal multipotent progenitor cells derived in cultures of developed organs, are of unknown identity and native distribution. We have prospectively identified perivascular cells, principally pericytes, in multiple human organs including skeletal muscle, pancreas, adipose tissue, and placenta, on CD146, NG2, and PDGF-Rbeta expression and absence of hematopoietic, endothelial, and myogenic cell markers. Perivascular cells purified from skeletal muscle or nonmuscle tissues were myogenic in culture and in vivo. Irrespective of their tissue origin, long-term cultured perivascular cells retained myogenicity; exhibited at the clonal level osteogenic, chondrogenic, and adipogenic potentials; expressed MSC markers; and migrated in a culture model of chemotaxis. Expression of MSC markers was also detected at the surface of native, noncultured perivascular cells. Thus, blood vessel walls harbor a reserve of progenitor cells that may be integral to the origin of the elusive MSCs and other related adult stem cells.     

The LKB1 tumor suppressor kinase in human disease

Inactivating germline mutations in the LKB1 gene underlie Peutz-Jeghers syndrome characterized by hamartomatous polyps and an elevated risk for cancer. Recent studies suggest the involvement of LKB1 also in more common human disorders including diabetes and in a significant fraction of lung adenocarcinomas. These observations have increased the interest towards signaling pathways of this tumor suppressor kinase. The recent breakthroughs in understanding the molecular functions of the LKB1 indicate its contribution as a regulator of cell polarity, energy metabolism and cell proliferation. Here we review how the substrates and cellular functions of LKB1 may be linked to Peutz-Jeghers syndrome and other diseases, and discuss how some of the molecular changes associated with altered LKB1 signaling might be used in therapeutic approaches.     

Precise Detection and Tracing of Trichoderma hamatum 382 in Compost-Amended Potting Mixes by Using Molecular Markers

Randomly amplified polymorphic DNA (RAPD) analysis and the PCR assay were used in combination with dilution plating on a semiselective medium to detect and enumerate propagules of Trichoderma hamatum 382, a biocontrol agent utilized in compost-amended mixes. Distinct and reproducible fingerprints were obtained upon amplification of purified genomic DNA of T. hamatum 382 with the random primers OPE-16, OPH-19, and OPH-20. Three amplified DNA fragments of 0.35 (OPE-16_0.35), 0.6 (OPH-19_0.6), and 0.65 (OPH-20_0.65) kb were diagnostic for T. hamatum 382, clearly distinguishing it from 53 isolates of four other Trichoderma spp. tested. Some isolates of T. hamatum shared these low-molecular-weight fragments with T. hamatum 382. However, RAPD analysis of isolates of T. hamatum with all three random primers used in consecutive PCR tests distinguished T. hamatum 382 from other isolates of T. hamatum. These three RAPD amplicons were cloned and sequenced, and pairs of oligonucleotide primers for each cloned fragment were designed. Use of the primers in the PCR assay resulted in the amplification of DNA fragments of the same size as the cloned RAPD fragments from genomic DNA of T. hamatum 382. A combination of dilution plating on a semiselective medium for Trichoderma spp. and PCR, with the RAPD primers OPH-19, OPE-16, and OPH-20 or the three sequence-characterized primers, was used successfully to verify the presence of T. hamatum 382 propagules in nine different soil, compost, and potting mix samples. All 23 Trichoderma isolates recovered on semiselective medium from commercial potting mixes fortified with T. hamatum 382 were identified as T. hamatum 382, whereas 274 Trichoderma isolates recovered from the other nine samples were negative in the PCR assay. Thus, this highly specific combination of techniques allowed detection and enumeration of propagules of T. hamatum 382 in fortified compost-amended potting mixes. Sequence-characterized amplified region markers also facilitated the development of a very simple procedure to amplify DNA of T. hamatum 382 directly from fortified compost-amended potting mixes.     

Scalable preparation of silCoat‐biocatalysts by use of a fluidized‐bed reactor

SilCoat‐biocatalysts are immobilized enzyme preparations with an outstanding robustness against leaching and mechanical stress and therefore promising tools for technical synthesis. They consist of a composite material made from a solid enzyme carrier and silicone. In this study, a method has been found to enable provision of these catalysts in large scale. It makes use of easily scalable fluidized‐bed technology and, in contrast to the original method, works in almost complete absence of organic solvent. Thus, it is both a fast and safe method. When the Pt‐catalyst required for silicone formation is cast on the solid enzyme carrier before coating, resulting composites resemble the original preparations in morphology, catalytic activity, and stability against leaching and mechanical forces. Only the maximum total content of silicone in the composites lies about 10% w/w lower resulting in an overall leaching stability below the theoretical maximum. When the Pt‐catalyst is mixed with cooled siloxane solution before coating, surficial coating of the enzyme carriers is achieved, which provides maximum leaching stability at very low silicone consumption. Thus, the technology offers the possibility to produce both composite and for the first time also core‐shell silCoat‐particles, and optimize leaching stability over mechanical strength according to process requirements.     

Adaptation to bipedal gait and fifth metatarsal structural properties in Australopithecus,Paranthropus, and Homo

Humans, unlike African apes, have relatively robust fifth metatarsals (Mt5) presumably reflecting substantial weight-bearing and stability function in the lateral column of the former. When this morphological difference emerged during hominin evolution is debated. Here we investigate internal diaphyseal structure of Mt5s attributed to Australopithecus (from Sterkfontein), Paranthropus (from Swartkrans), and Homo (from Olduvai, Dmanisi, and Dinaledi) placed in the context of human and African ape Mt5 internal diaphyseal structure. ‘Whole-shaft’ properties were evaluated from 17 cross sections sampling 25% to 75% diaphyseal length using computed tomography. To assess structural patterns, scaled cortical bone thicknesses (sCBT) and scaled second moments of area (sSMA) were visualized and evaluated through penalized discriminant analyses. While the majority of fossil hominin Mt5s exhibited ape-like sCBT, their sSMA were comparatively more human-like. Human-like functional loading of the lateral column existed in at least some fossil hominins, although perhaps surprisingly not in hominins from Dmanisi or Dinaledi.     

The structure and binding behavior of the bacterial cell surface layer protein SbsC

Surface layers (S-layers) comprise the outermost cell envelope component of most archaea and many bacteria. Here we present the structure of the bacterial S-layer protein SbsC from Geobacillus stearothermophilus, showing a very elongated and flexible molecule, with strong and specific binding to the secondary cell wall polymer (SCWP). The crystal structure of rSbsC((31-844)) revealed a novel fold, consisting of six separate domains, which are connected by short flexible linkers. The N-terminal domain exhibits positively charged residues regularly spaced along the putative ligand binding site matching the distance of the negative charges on the extended SCWP. Upon SCWP binding, a considerable stabilization of the N-terminal domain occurs. These findings provide insight into the processes of S-layer attachment to the underlying cell wall and self-assembly, and also accommodate the observed mechanical strength, the polarity of the S-layer, and the pronounced requirement for surface flexibility inherent to cell growth and division.