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101.
Hashimoto T Tashiro T Sasaki M Takikawa H 《Bioscience, biotechnology, and biochemistry》2007,71(8):2046-2051
A new and concise synthesis of (+/-)-sundiversifolide (1), an allelopathic bisnor-sesquiterpene lactone isolated from germinating sunflower (Helianthus annuus L.) seeds, was achieved by employing Lewis acid-mediated Claisen rearrangement as the key step. 相似文献
102.
Morimura K Yamazaki C Hattori Y Makabe H Kamo T Hirota M 《Bioscience, biotechnology, and biochemistry》2007,71(11):2837-2840
A chromene-type compound, daedalin A (1), was isolated from mycelial culture broth of Daedalea dickinsii. Based on spectroscopic data, the structure of 1 was found to be (2R)-6-hydroxy-2-hydroxymethyl-2-methyl-2H-chromene. Daedalin A (1) strongly inhibited the activity of tyrosinase (IC(50): 194 muM). In addition, 1 also showed 1,1-diphenyl-2-picrylhydrazyl scavenging activity (IC(50): 16.9 microM) and superoxide anion scavenging activity (IC(50): 28.5 microM). 相似文献
103.
Pack SP Doi A Nonogawa M Kamisetty NK Devarayapalli KC Kodaki T Makino K 《Nucleosides, nucleotides & nucleic acids》2007,26(10-12):1589-1593
Oxanine (Oxa), which is one of the major products generated from guanine by nitrosative oxidation and is as long-lived as Gua in DNA, has been thought to be one of the major causes for NO-induced DNA damage. In the present study, using several synthetic Oxa-containing oligodeoxynucleotides, biophysical stability and enzymatic recognition of Oxa was investigated in DNA strands. It was found that Oxa did not mediate marked distortion in the whole DNA structure although Oxa pairing with 4 normal bases decreased thermal stability of the DNA duplexes compared to Gua:Cyt base pair. Regarding the responses of the DNA-relevant enzymes to Oxa, it was determined that Oxa was recognized as Gua except that DNA polymerases incorporated Thy as well as Cyt opposite Oxa. These results imply that Oxa tends to behave as a kind of naturally occurring base, Gua and therefore, would be involved in the genotoxic and cytotoxic threats of NO in cellular system. 相似文献
104.
105.
Sattasuk K Nozawa A Tozawa Y Kakinuma Y Akita M 《Bioscience, biotechnology, and biochemistry》2011,75(11):2200-2206
We identified a gene product of At5g19500 (At5g19500p) from Arabidopsis thaliana that is homologous to EcTyrP, a tyrosine-specific transporter from Escherichia coli. Computational analyses of the amino acid sequence of At5g19500p predicted 11 transmembrane domains (TMDs) and a potential plastid targeting signal at its amino terminus. As a first step toward understanding the possible role of At5g19500p in plant cells, we attempted to determine the localization of At5g19500p by an in vitro chloroplastic import assay using At5g19500p translated in a cell-free wheat germ system (Madin et al., Proc. Natl. Acad. Sci. USA, 97, 559-564 (2000)), followed by subfractionation of the chloroplasts. At5g19500p was successfully imported into chloroplasts, and the newly transported mature form of At5g19500p was recovered from the inner envelope membrane. 相似文献
106.
Despite recent progress in fluorescence techniques employed to observe protein localization in living cells, the in vitro chloroplastic protein transport assay remains a useful tool for determining the destinations of proteins. Although an in vitro synthesized, radiolabeled precursor protein is frequently used as the transport substrate, we have developed a transport assay system with a non-radiolabeled precursor protein that carries an epitope tag and is overexpressed in Escherichia coli. Thus, a transported protein can be detected by immunoblotting (Inoue et al., Plant Physiol. Biochem., 46, 541-549 (2008)). Here, we propose another in vitro protein transport system that combines fluorescence techniques. We attempted to use two types of precursors: a green fluorescent protein (GFP)-fused precursor and a fluorescent dye-labeled one. Both were successfully imported into chloroplasts. However, the fluorescent dye-labeled precursor was more advantageous than the GFP-fused precursor in the in vitro system. 相似文献
107.
Haniu M Horan T Spahr C Hui J Fan W Chen C Richards WG Lu HS 《Protein science : a publication of the Protein Society》2011,20(11):1802-1813
Human Dickkopf‐1 (huDKK1), an inhibitor of the canonical Wnt‐signaling pathway that has been implicated in bone metabolism and other diseases, was expressed in engineered Chinese hamster ovary cells and purified. HuDKK1 is biologically active in a TCF/lef‐luciferase reporter gene assay and is able to bind LRP6 coreceptor. In SDS‐PAGE, huDKK1 exhibits molecular weights of 27–28 K and 30 K at ~ 1:9 ratio. By MALDI‐MS analysis, the observed molecular weights of 27.4K and 29.5K indicate that the low molecular weight form may contain O‐linked glycans while the high molecular weight form contains both N‐ and O‐linked glycans. LC‐MS/MS peptide mapping indicates that ~ 92% of huDKK1 is glycosylated at Asn225 with three N‐linked glycans composed of two biantennary forms with 1 and 2 sialic acid (23% and 60%, respectively), and one triantennary structure with 2 sialic acids (9%). HuDKK1 contains two O‐linked glycans, GalNAc (sialic acid)‐Gal‐sialic acid (65%) and GalNAc‐Gal[sialic acid] (30%), attached at Ser 30 as confirmed by β‐elimination and targeted LC‐MS/MS. The 10 intramolecular disulfide bonds at the N‐ and C‐terminal cysteine‐rich domains were elucidated by analyses including multiple proteolytic digestions, isolation and characterization of disulfide‐containing peptides, and secondary digestion and characterization of selected disulfide‐containing peptides. The five disulfide bonds within the huDKK1 N‐terminal domain are unique to the DKK family proteins; there are no exact matches in disulfide positioning when compared to other known disulfide clusters. The five disulfide bonds assigned in the C‐terminal domain show the expected homology with those found in colipase and other reported disulfide clusters. 相似文献
108.
Chow R Lin A Tonai R Bolanos R Connor C Mendoza A Heminger R Chow M Ho E Kang J Gindy L Fu C Rao A Gau JF Wang BC Klich I Ratajczak J Ratajczak M Petz LD 《Cytotherapy》2011,13(9):1105-1119
Background aimsLimited cell dose has hampered the use of cord blood transplantation (CBT) in adults. One method of minimizing nucleated cell loss in cord blood (CB) processing is to deplete or reduce plasma but not red blood cells - plasma depletion/reduction (PDR).MethodsThe nucleated cell loss of PDR was studied, and determined to be less than 0.1% in the discarded supernatant plasma fraction in validation experiments. After testing and archival sampling, the median nucleated cell recovery for PDR processing was 90%, and median CD34+ cell recovery 88%. In a CB bank inventory of 12 339 products with both pre- and post-processing total nucleated cells (TNC), PDR processing resulted in median post-processing TNC recoveries of 90.0% after testing and archival samples removal. Using the same 10 CB units divided into two halves, we compared directly the recovery of PDR against hydroxyethyl starch red cell reduction (RCR) for TNC, CD34+ cells and colony-forming units (CFU-GM, CFU-E, CFU-GEMM and total CFU) after parallel processing. We also compared the loss of very small embryonic-like stem cells (VSEL).ResultsWe demonstrated significantly higher recoveries using PDR for TNC (124%), CD34+ cells (121%), CFU-GM (225%), CFU-GEMM (201%), total CFU (186%) and VSEL (187%). The proportion of high TNC products was compared between 10 912 PDR and 38 819 RCR CB products and found to be 200% higher for products that had TNC ≥150 × 107 (P = 0.0001) for the PDR inventory.ConclusionsOur data indicate that PDR processing of CB provides a significantly more efficient usage of this valuable and scarce resource. 相似文献
109.
Santosh B. Satbhai Takafumi Yamashino Ryo Okada Yuji Nomoto Takeshi Mizuno Yuki Tezuka Tomonori Itoh Mitsuru Tomita Susumu Otsuki Setsuyuki Aoki 《DNA research》2011,18(1):39-52
The pseudo-response regulators (PRRs) are the circadian clock component proteins in the model dicot Arabidopsis thaliana. They contain a receiver-like domain (RLD) similar to the receiver domains of the RRs in the His–Asp phosphorelay system, but the RLDs lack the phosphoacceptor aspartic acid residue invariably conserved in the receiver domains. To study the evolution of PRR genes in plants, here we characterize their homologue genes, PpPRR1, PpPRR2, PpPRR3 and PpPRR4, from the moss Physcomitrella patens. In the phylogenetic analysis, PpPRRs cluster together, sister to an angiosperm PRR gene subfamily, illustrating their close relationships with the angiosperm PRRs. However, distinct from the angiosperm sequences, the RLDs of PpPRR2/3/4 exhibit a potential phosphoacceptor aspartic acid–aspartic acid–lysine (DDK) motif. Consistently, the PpPRR2 RLD had phosphotransfer ability in vitro, suggesting that PpPRR2 functions as an RR. The PpPRR1 RLD, on the other hand, shows a partially diverged DDK motif, and it did not show phosphotransfer ability. All PpPRRs were expressed in a circadian and light-dependent manner, with differential regulation between PpPRR2/4 and PpPRR1/3. Altogether, our results illustrate that PRRs originated from an RR(s) and that there are intraspecific divergences among PpPRRs. Finally, we offer scenarios for the evolution of the PRR family in land plants. 相似文献
110.
Beck CR McKenzie BC Hashim AB Harris RC Zanuzdana A Agboado G Orton E Béchard-Evans L Morgan G Stevenson C Weston R Mukaigawara M Enstone J Augustine G Butt M Kim S Puleston R Dabke G Howard R O'Boyle J O'Brien M Ahyow L Denness H Farmer S Figureroa J Fisher P Greaves F Haroon M Haroon S Hird C Isba R Ishola DA Kerac M Parish V Roberts J Rosser J Theaker S Wallace D Wigglesworth N Lingard L Vinogradova Y Horiuchi H Peñalver J Nguyen-Van-Tam JS 《PloS one》2011,6(12):e29249