Von einem, der auszog, das Evaluieren zu lernen

Complete orphan NRPS/PKS gene clusters identified from the Subsection V cyanobacterial genomes. The genomes in which the orphan gene clusters were identified are stated to the left of each cluster. Fragments of gene clusters, or differences from the gene cluster shown are noted in the image. NRPS/PKS genes are represented by green arrows. Additional genes that may be involved in biosynthesis are represented by blue arrows. Genes encoding hypothetical proteins and transposases are represented by silver arrows. (PDF 307 kb

Chemoenzymatic Synthesis of <i>C</i>‑4′-Spiro-oxetanoribonucleosides

Novozyme-435-mediated diastereoselective deacylation of one of the two diastereotopic acyloxymethyl groups in 5-<i>O</i>-acyl-4-<i>C</i>-acyloxymethyl-3-<i>O</i>-benzyl-1,2-<i>O</i>-isopropylidene-α-d-ribofuranose has been achieved in quantitative yield. The exclusive selectivity of the lipase for the 5-<i>O</i>-acyl over the 4-<i>C</i>-acyloxymethyl group in the substrate was confirmed by chemical transformation of enzymatically monodeacetylated compound to 1,2-<i>O</i>-isopropylidene-<i>C</i>-4-spiro-oxetanoribofuranose. Further, the selective biocatalytic deacylation methodology has been utilized for the efficient synthesis of <i>C</i>-4′-spiro-oxetanoribonucleosides of uracil (U) and thymine (T) in 37 and 45% overall yields, respectively

Regioselective Cope Rearrangement and Prenyl Transfers on Indole Scaffold Mimicking Fungal and Bacterial Dimethylallyltryptophan Synthases

Aromatic prenyltransferases are an actively mined enzymatic class whose biosynthetic repertoire is growing. Indole prenyltransferases catalyze the formation of a diverse set of prenylated tryptophan and diketopiperazines, leading to the formation of fungal toxins with prolific biological activities. At a fundamental level, the mechanism of C4-prenylation of l-tryptophan recently has surfaced to engage a debate between a “direct” electrophilic alkylation mechanism (for wt DMATS and FgaPT2) versus an indole C3–C4 “Cope” rearrangement followed by rearomatization (for mutant FgaPT2). Herein we provide the first series of regioselectively tunable conditions for a Cope rearrangement between C3 and C4 positions. Biomimetic conditions are reported that effect a [3,3]-sigmatropic shift whose two-step process is interrogated for intramolecularity and rate-limiting general base-promoted mechanism. Solvent polarity serves a crucial role in changing the regioselectivity, resulting in sole [1,3]-shifts under decalin. An intermolecular variant is also reported that effectively prenylates the C3 position of l-tryptophan, resulting in products that mimic the structures accessed by bacterial indole prenyltransferases. We report an elaborate investigation that includes screening various substituents and measuring steric and electronic effects and stereoselectivity with synthetically useful transformations

MOESM1 of Design, synthesis and biological evaluation of antimalarial activity of new derivatives of 2,4,6-s-triazine

Additional file 1. Additional figures

Robust and Multifunctional Nanosheath for Chemical and Biological Nanodevices

The contribution of advanced nanoscale chemical and biological devices to life science has been limited to a small number of nanomaterials, due to the absence of effective surface modification routes. Herein, we demonstrate a polymer-like nanosheath synthesized by nonthermal plasma technology (NPT) that can protect the core nanomaterial from the solution environment and provide a multifunctional platform for chemical and biological nanosensors. For ZnO nanowires (NWs) which are unstable in solution, we demonstrate that this nanosheath makes it possible for ZnO NW field-effect transistors to act as a pH sensor for 24 h and a biosensor for the real-time, label-free detection of liver cancer markers

<i>eh</i>Dmc1 binds DNA.

<p><b>A.</b> Increasing concentrations of <i>eh</i>Dmc1 (1.3 μM, lane 2; 2.6 μM, lane 3; 3.9 μM, lane 4; and 5.2 μM, lane 5) were incubated with ssDNA (³²P-labeled H3 ssDNA). <b>B.</b> The mean binding percentages were graphed for three independent experiments from <b>A</b>. Error bars represent SEM. <b>C.</b> Increasing concentrations of <i>eh</i>Dmc1 (5.2 μM, lane 2; 10.4 μM, lane 3; 20.8 μM, lane 4; and 31.2 μM, lane 5) were incubated with dsDNA (³²P-labeled H3 annealed to H3c). <b>D.</b> The mean binding percentages were graphed for three independent experiments from <b>C</b>. Error bars represent SEM. Lane 1 for <b>A</b> and <b>C</b> is devoid of protein, and lane 6 for <b>A</b> and <b>C</b> was SDS/PK (S/P) treated containing the highest concentration of <i>eh</i>Dmc1.</p

mHop2-Mnd1 and Ca²⁺ stimulate <i>eh</i>Dmc1-mediated D-loop formation.

<p><i>eh</i>Dmc1 was incubated with ³²P-radiolabeled OL90 ssDNA in the absence (lanes 1–4 and 9–12) or presence of calcium (lanes 5–8 and 13–16) and/or mHop2-Mnd1 (lanes 9–16). The reaction was initiated with the addition of supercoiled dsDNA. Aliquots were removed at the indicated times, deproteinized, and the reaction products were separated by agarose gel electrophoresis. Lanes 1, 5, 9, and 13 were lacking <i>eh</i>Dmc1. Mean values from three individual experiments were graphed. Error bars represent SEM.</p

List of oligonucleotides.

<p>Primers 1–5 were used to isolate and modify the cDNA encoding <i>E</i>. <i>histolytica DMC1</i> and <i>RAD51</i>. H3, OL83-1, and OL90 were ³²P-radiolabeled using [³²P-<b>γ</b>]-ATP and T4-PNK. ³²P-H3 and ³²P-OL83-1 were annealed with H3c and OL83-2 oligonucleotides, respectively, to form double-stranded DNA substrates. ³²P-OL90 was used in the D-loop and nuclease protection assay.</p><p>List of oligonucleotides.</p

mHop2-Mnd1 interacts with <i>eh</i>Dmc1.

<p><i>eh</i>Dmc1 was mixed with Affi-Gel matrix conjugated to either mHop2-Mnd1 (lanes 2–4) or bovine serum albumin (BSA, lanes 5–7). After a wash, bound protein was eluted with SDS. The supernatant (S), wash (W), and eluate (E) were subjected to SDS-PAGE, and the gel was stained with Coomassie blue.</p

<i>eh</i>Dmc1 catalyzes D-loop formation.

<p><b>A.</b> Schematic of D-loop formation assay (ss, single-strand oligonucleotide; sc, supercoiled dsDNA). <b>B.</b><i>eh</i>Dmc1 was incubated with ³²P-radiolabeled OL90 ssDNA (lane 2), dsDNA (lane 3) prior to the addition of dsDNA or ssDNA (lanes 2 and 3, respectively), or both ssDNA and dsDNA (lane 4) simultaneously. Lane 1 is devoid of protein. After a 12 min incubation, an aliquot was removed and deproteinized prior to separation on an agarose gel. The mean percent of six independent experiments was graphed. Error bars represent SEM. <b>C.</b><i>eh</i>Dmc1 was incubated with ³²P-OL90 ssDNA in the presence of 2 mM nucleotide (ATP, lanes 1–4), ATP-<b>γ</b>-S (lane 5), ADP (lane 6) and AMP-PNP (lane 7). Lane 8 was devoid of nucleotide. At the indicated times, an aliquot was removed and processed as described in <b>B</b>. The mean percent of six independent experiments was graphed. Error bars represent SEM.</p