Search results for "Complementary"
showing 10 items of 1156 documents
Isolactarane and Sterpurane Sesquiterpenoids from the Basidiomycete Phlebia uda
2012
Three new sesquiterpenoids, named udasterpurenol A, udalactarane A, and udalactarane B, as well as the known compounds hyphodontal and sterpuric acid have been isolated from the basidiomycete Phlebia uda. These compounds represent the first natural products described from this species. The structures were elucidated by NMR spectroscopy and mass spectrometry. Udalactaranes A and B were isolated as mixtures with their respective epimeric acetals. These mixtures inhibited the spore germination of the plant pathogenic fungus Fusarium graminearum at 10 and 5 μg/mL, respectively, and were active against Jurkat cells with IC(50) values of 101 and 42 μM, respectively.
Bio-sintering processes in hexactinellid sponges: Fusion of bio-silica in giant basal spicules from Monorhaphis chuni☆
2009
The two sponge classes, Hexactinellida and Demospongiae, comprise a skeleton that is composed of siliceous skeletal elements (spicules). Spicule growth proceeds by appositional layering of lamellae that consist of silica nanoparticles, which are synthesized via the sponge-specific enzyme silicatein. While in demosponges during maturation the lamellae consolidate to a solid rod, the lamellar organization of hexactinellid spicules largely persists. However, the innermost lamellae, near the spicule core, can also fuse to a solid axial cylinder. Similar to the fusion of siliceous nanoparticles and lamella, in several hexactinellid species individual spicules unify during sintering-like processe…
Regulated expression and phosphorylation of the 23-26-kDa ras protein in the sponge Geodia cydonium.
1990
We have cloned, sequenced and examined the sponge Geodia cydonium cDNA encoding a protein homologous to ras proteins. The sponge ras protein has a more conserved N-terminal region and a less conserved C-terminal region, especially in comparison to Dictyostelium discoideum; the similarity to human c-Ha-ras-1 and to Saccharomyces cerevisiae is less pronounced. The sponge ras cDNA comprises five TAG triplets; at the translational level these UAG termination codons are suppressed by a Gln-tRNA. The sponge ras protein was isolated and partially purified (23-26 kDa) and found to undergo phosphorylation at a threonine moiety, when dissociated cells were incubated in the presence of a homologous ag…
Functional analysis of the isoforms of an ABI3-like factor of Pisum sativum generated by alternative splicing
2009
At least seven isoforms (PsABI3-1 to PsABI3-7) of a putative, pea ABI3-like factor, originated by alternative splicing, have been identified after cDNA cloning. A similar variability had previously only been described for monocot genes. The full-length isoform, PsABI3-1, contains the typical N-terminal acidic domains and C-terminal basic subdomains, B1 to B3. Reverse transcriptase-PCR analysis revealed that the gene is expressed just in seeds, starting at middle embryogenesis; no gene products are observed in embryo axes after 18 h post-imbibition although they are more persistent in cotyledons. The activity of the isoforms was studied by yeast one-hybrid assays. When yeast was transformed …
Serological identification and expression analysis of gastric cancer-associated genes
2002
Serological identification of tumour antigens by recombinant expression cloning has proved to be an effective strategy for the identification of cancer-associated genes having a relevance to cancer aetiology and progression, and for defining possible targets for immunotherapeutic intervention. In the present study we applied this technique to identify immunogenic proteins for gastric cancer that resulted in isolation of 14 distinct serum-reactive antigens. In order to evaluate their role in tumourigenesis and assess the immunogenicity of the identified antigens, we characterised each cDNA clone by DNA sequence analysis, mRNA tissue distribution, comparison of mRNA levels in cancerous and ad…
Developmental expression of two Haliotis asinina hemocyanin isoforms
2005
Hemocyanins are large copper-containing respiratory proteins that play a role in oxygen transport in many molluscs. In some species only one hemocyanin isoform is present while in others two are expressed. The physiological relevance of these isoforms is unclear and the developmental and tissue-specific expression of hemocyanin genes is largely unknown. Here we show that two hemocyanin genes in the gastropod Haliotis asinina, which encode H. asinina hemocyanin (HaH1) and HaH2 isoforms, are developmentally expressed. These genes initially are expressed in a small number of mesenchyme cells at trochophore and pre-torsional veliger stages, with HaH1 expression slightly preceding HaH2. These ce…
Quantitative RT-PCR measurement of human cytochrome P-450s: application to drug induction studies.
2000
A quantitative RT-PCR assay has been developed that is able to measure the mRNA content of the major human CYPs (1A1, 1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, 3A4, and 3A5). The technique is highly specific, reproducible, rapid, and sensitive enough to quantitate low and high abundant mRNAs. The PCR primers were selected to specifically match each CYP mRNA, to have a very close annealing temperature, and to render PCR products of similar sizes. The PCR conditions were designed to allow the simultaneous measurement of the various human liver CYPs in a single run. To achieve precise and reproducible quantitation of each cytochrome mRNA, a external standard (luciferase mRNA) is added to the probes …
Different La/SS-B mRNA isoforms are expressed in salivary gland tissue of patients with primary Sjogren's syndrome
1996
Recently we isolated a La/SS-B mRNA isoform from a cDNA library made from peripheral blood lymphocytes of a patient with primary Sjögren's Syndrome. In the La/SS-B mRNA isoform the exon 1 was replaced. The alternative exon was termed exon 1'. Genomic analysis showed that the exon 1' La mRNA was the result of a promoter-switch in combination with alternative splicing. Due to the unusual structure of the exon 1' La/SS-B mRNA, the function and the behaviour under physiological and pathophysiological conditions in tissue of patients with primary Sjögren's syndrome or Systemic Lupus Erythematosus remained obscure. Therefore assays were established allowing a qualitative and quantitative estimati…
A new metallothionein gene from the giant keyhole limpet Megathura crenulata.
2003
Abstract Metallothioneins (MTs) are small soluble proteins ubiquitously expressed in animals and plants. Different isoforms are present in deuterostomes and protostomes. They do not differ greatly in primary structure, but are clearly distinguishable. Here, I present the gene and the complete cDNA of a novel MT from the mollusk Megathura crenulata . This protein is closely related to the Cu-inducible MTs of the vineyard snail Helix pomatia , but has also some minor sequence features typical of Cd-inducible isoforms of H . pomatia and other molluscs. Overall, the deduced primary structure is similar to the known molluscan MTs, but in addition possesses an insertion of 5 amino acids not found…
Gene structure and hemocyanin isoform HtH2 from the mollusc Haliotis tuberculata indicate early and late intron hot spots.
2002
Abstract We have cloned and sequenced cDNAs coding for the complete primary structure of HtH2, the second hemocyanin isoform of the marine gastropod Haliotis tuberculata. The deduced protein sequence comprises 3399 amino acids, corresponding to a molecular mass of 392 kDa. It shares only 66% of structural identity with the previously analysed first isoform HtH1, and according to a molecular clock, the two isoforms of Haliotis hemocyanin separated ca. 320 million years ago. By genomic polymerase chain reaction and 5′ race, we have also sequenced the complete gene of HtH2 (18,598 bp), except of the 5′ region in front of the secreted protein. It encompasses 15 exons and 14 introns and shows se…