Showing papers by "Tsuyoshi Tanaka published in 2006"
TL;DR: From the identification and characterization of several surface and transmembrane magnetosome proteins, it is postulated that magnetosomes are derived from the cytoplasmic membrane (CM), and a comparative proteomic analysis of the MM and CM of the magnetotactic bacterium, Magnetospirillum magneticum AMB‐1, suggests that the MM isderived from the CM.
Abstract: Prokaryotes are known to have evolved one or more unique organelles. Although several hypotheses have been proposed concerning the biogenesis of these intracellular components, the majority of these proposals remains unclear. Magnetotactic bacteria synthesize intracellular magnetosomes that are enclosed by lipid bilayer membranes. From the identification and characterization of several surface and transmembrane magnetosome proteins, we have postulated that magnetosomes are derived from the cytoplasmic membrane (CM). To confirm this hypothesis, a comparative proteomic analysis of the magnetosome membrane (MM) and CM of the magnetotactic bacterium, Magnetospirillum magneticum AMB-1, was undertaken. Based on the whole genome sequence of M. magneticum AMB-1, 78 identified MM proteins were also found to be prevalent in the CM, several of which are related to magnetosome biosynthesis, such as Mms13, which is tightly bound on the magnetite surface. Fatty acid analysis was also conducted, and showed a striking similarity between the CM and MM profiles. These results suggest that the MM is derived from the CM.
144 citations
TL;DR: DNA extraction from whole blood using these modified BMPs, followed by PCR, was successfully performed, and automated single nucleotide polymorphism (SNP) detection of the aldehyde dehydrogenase 2 (ALDH2) was demonstrated.
Abstract: Bacterial magnetic particles (BMPs) were modified with 3-[2-(2-aminoethylamino)-ethylamino]-propyltrimethoxysilane (AEEA) to produce a dense amine surface. Modification of BMPs in a toluene solution resulted in an increased amine yield, and approximately 11.3 × 104 surface amines were detected on a single particle. The modified BMPs were capable of efficient electrostatic capture of DNA. The maximum amount of DNA captured on 10 µg of aminosilane-modified BMPs was 600 ng. A 10 mM phosphate buffer effectively released the captured DNA. This efficiency was dramatically enhanced by incubation at 80°C and DNA recovery from aminosilane-modified BMPs approached 95%. DNA extraction from whole blood using these modified BMPs, followed by PCR, was successfully performed. Furthermore, automated single nucleotide polymorphism (SNP) detection of the aldehyde dehydrogenase 2 (ALDH2) was demonstrated. © 2006 Wiley Periodicals, Inc.
54 citations
TL;DR: Results of real-time PCR confirmed that the proposed method permitted the accurate determination of genetically modified DNA composition and correlated well with results obtained by conventional cetyltrimethylammonium bromide (CTAB)-based methods.
21 citations
TL;DR: Use of the TFT photosensor will allow the development of a disposable photodetecting device for DNA chip systems and was similar to a previous analysis using radioisotope‐labeled oligonucleotides.
Abstract: A thin film transistor (TFT) photosensor fabricated by semiconductor integrated circuit (IC) technology was applied to DNA chip technology. The surface of the TFT photosensor was coated with TiO2 using a vapor deposition technique for the fabrication of optical filters. The immobilization of thiolated oligonucleotide probes onto a TiO2-coated TFT photosensor using γ-aminopropyltriethoxysilane (APTES) and N-(γ-maleimidobutyloxy) sulfosuccinimide ester (GMBS) was optimized. The coverage value of immobilized oligonucleotides reached a plateau at 33.7 pmol/cm2, which was similar to a previous analysis using radioisotope-labeled oligonucleotides. The lowest detection limits were 0.05 pmol/cm2 for quantum dot and 2.1 pmol/cm2 for Alexa Fluor 350. Furthermore, single nucleotide polymorphism (SNP) detection was examined using the oligonucleotide-arrayed TFT photosensor. A SNP present in the aldehyde dehydrogenase 2 (ALDH2) gene was used as a target. The SNPs in ALDH2*1 and ALDH2*2 target DNA were detected successfully using the TFT photosensor. DNA hybridization in the presence of both ALDH2*1 and ALDH2*2 target DNA was observed using both ALDH2*1 and ALDH2*2 detection oligonucleotides-arrayed TFT photosensor. Use of the TFT photosensor will allow the development of a disposable photodetecting device for DNA chip systems. © 2006 Wiley Periodicals, Inc.
15 citations
TL;DR: The results demonstrated that the specific sequence differences between long DNA fragments can be measured using force-based detection, and indicated that force- based detection potentially can be applied toward many other mismatched DNA detection techniques besides species-specific identification of tuna.
7 citations