Chiroptical Polymer Functionalized by Chiral Nanofibrillar Network

Chirality is one of the basic factors that influence a wide range of activities from chemical synthesis to tissue construction in life phenomena. Recently, researchers have attempted to use chirality as an optical signal. In animals, it is used to transmit information to insects and crustaceans, and it has also been confirmed that it promotes growth in plants. This chapter presents a new organic system that produces a chiral optical signal, that is, circularly polarized luminescence (CPL), which has been attracting attention in recent years. In particular, the chapter is focused on the generating CPL through chirality induction with the chiral self-assembling phenomenon and explaining its application as an optical film

Wortmannin, a specific inhibitor of phosphatidylinositol-3-kinase, induces accumulation of DNA double-strand breaks

Wortmannin, a fungal metabolite, is a specific inhibitor of the phosphatidylinositol 3-kinase (PI3K) family, which includes double-stranded DNA dependent protein kinase (DNA-PK) and ataxia telangiectasia mutated kinase (ATM). We investigated the effects of wortmannin on DNA damage in DNA-PK-deficient cells obtained from severe combined immunodeficient mice (SCID cells). Survival of wortmannin-treated cells decreased in a concentration-dependent manner. After treatment with 50 μM wortmannin, survival decreased to 60% of that of untreated cells. We observed that treatment with 20 and 50 μM wortmannin induced DNA damage equivalent to that by 0.37 and 0.69 Gy, respectively, of γ-ray radiation. The accumulation of DNA double-strand breaks (DSBs) in wortmannin-treated SCID cells was assessed using pulsed-field gel electrophoresis. The maximal accumulation was observed 4 h after treatment. Moreover, the presence of DSBs was confirmed by the ability of nuclear extracts from γ-ray-irradiated SCID cells to produce in vitro phosphorylation of histone H2AX. These results suggest that wortmannin induces cellular toxicity by accumulation of spontaneous DSBs through inhibition of ATM

Photochemical characterization of actinorhodopsin and its functional existence in the natural host

Actinorhodopsin (ActR) is a light-driven outward H+ pump. Although the genes of ActRs are widely spread among freshwater bacterioplankton, there are no prior data on their functional expression in native cell membranes. Here, we demonstrate ActR phototrophy in the native actinobacterium. Genome analysis showed that Candidatus Rhodoluna planktonica, a freshwater actinobacterium, encodes one microbial rhodopsin (RpActR) belonging to the ActR family. Reflecting the functional expression of RpActR, illumination induced the acidification of the actinobacterial cell suspension and then elevated the ATP content inside the cells. The photochemistry of RpActR was also examined using heterologously expressed RpActR in Escherichia coli membranes. The purified RpActR showed lambda(max) at 534 nm and underwent a photocycle characterized by the very fast formation of M intermediate. The subsequent intermediate, named P-620, could be assigned to the 0 intermediate in other H+ pumps. In contrast to conventional 0, the accumulation of P620 remains prominent, even at high pH. Flash-induced absorbance changes suggested that there exists only one kind of photocycle at any pH. However, above pH 7, RpActR shows heterogeneity in the H+ transfer sequences: one first captures H+ and then releases it during the formation and decay of P-650, while the other first releases H+ prior to H+ uptake during P-620 formation. (C) 2016 Elsevier B.V. All rights reserved

Urinary excretion of biopyrrin in unconjugated hyperbilirubinemia

We determined the urinary excretion of biopyrrin, an oxidative metabolite of bilirubin, in three jaundiced subjects with unconjugated hyperbilirubinemia and in eight normal controls. We used an enzyme-linked immunosorbent assay (ELISA) and an anti-bilirubin monoclonal antibody, 24G7 (Shino-Test Corporation, Kanagawa, Japan). The biopyrrin excretions, expressed as the ratio in urine of biopyrrin to creatinine, were measured in random urine specimens from jaundiced adults and were compared to the same in random urine specimens from normal adults. The central 95% of the distribution range, defined by us as the reference range for the urinary biopyrrin/creatinine excretion, was 0.5 -3.3 mol/g in presumably healthy adults. The biopyrrin/creatinine excretions from the jaundiced adults were significantly higher than the reference range (p<0.05). We found that for the 24-hr biopyrrin excretion from normal subjects, and that the central 95% of the data was 0.9 -1.5 mol/day; the amounts in the jaundiced adults were significantly higher than the reference range (p<0.05). Our observations suggest that there is an enhanced bilirubin catabolism to biopyrrin in subjects with unconjugated hyperbilirubinemia. Bilirubin, Jaundice, Gilbert syndrome, Random and 24-hr urine, Biopyrrin, Hyperbilirubinemi

[1.1]meta-Stilbenophanes as calixarene analogs: preparation, crystal structure, and cis-trans photoisomerization

Abstract-Three isomers of [1.1]meta-stilbenophane were synthesized by the McMurry reaction of diarylmethane dialdehyde and their crystal structures and photochemical properties were investigated. X-ray crystallographic analyses of these isomers revealed that they were assigned to a trans-trans (t-t) form with a 1,3-alternate conformation, a cis-trans (c-t) form with a distorted-cone conformation, and a cis-cis (c-c) form with a 1,2-alternate conformation. A 1 H NMR study indicated that a t-t isomer could be completely transformed into a 35:65 mixture of c-t and c-c isomers by photoirradiation at 254 nm