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Volume 45, Issue 2
Displaying 1-10 of 10 articles from this issue
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Takeshi Hirokawa, Natsuki Ikuta, Tatsuya Yoshiyama, Hikaru Okamoto, Ta ...2001 Volume 45 Issue 2 Pages 103-109
Published: June 15, 2001
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSAlthough chromatography is widely utilized, it is behind the other analytical methods from the viewpoint of the standardization of the data. This is because usual chromatograms are strongly dependent on the used hardware. Capillary electrophoresis is not either the exception: The obtained electropherograms are also dependent on the hardware such as capillary length, capillary inner surface, applied voltage, and thermostatting capacity etc, even if the same background electrolyte and the same sample is used. We have developed a conversion method of the time-based electropherograms of capillary zone electrophoresis (CZE) into the mobility-based ones by removing contribution of electroosmotic flow considering temperature rise caused by Joule heating. The conversion method also contained correction for delay of migration time caused by relaxation of potential gradient at sample plug. In this paper, after discussing the factors affecting migration time of CZE, electropherograms of rare-earth ions obtained using different migration voltage were converted to demonstrate utility of our method proposed for standardization (data transfer). The conversion method was also successfully applied to electropherograms of several rations obtained by using field enhanced sample stacking.View full abstractDownload PDF (1091K) -
Kazuhiko Tsukagoshi2001 Volume 45 Issue 2 Pages 111-115
Published: June 15, 2001
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSLiposome immunoassays have been studied extensively, since the introduction by Kinsky et al. The mode of the assay, releasing entrapped signal-generating materials from liposomes, is based on destabilization of liposomal membrane. The quantity of released signal-generating materials is proportional to the concentration of analytes. Monitoring is generally by spectrophotometric and fluorimetric methods. However, as far as we know, few investigations have been made with regard to dyestuff-containing liposomes as a labeling reagent in immunoassay. In 2000 we proposed an immunoassay using chemiluminescence detection of dyestuff-containing liposomes as a labeling reagent. The immunoassay features high sensitivity, a small sample volume, and easy and rapid operation. In this report, the new immunoassay using capillary electrophoresis-chemiluminescence detection of dyestuff-containing liposomes as a labeling reagent is shortly introduced together with their background.View full abstractDownload PDF (614K) -
Shigeru Terabe, Joselito P. Quirino, Michal J. Markuszewski, Naoko Ino ...2001 Volume 45 Issue 2 Pages 117-121
Published: June 15, 2001
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSAbout 300 small molecules to be found in the cell as metabolic intermediates are listed and classified according to the chemical characteristics. To develop a comprehensive analytical technique of these metabolic intermediates, capillary electrophoresis (CE) is considered to be a promising technique. A mixture of 22 phenylthiohydantoin (PTH) amino acids and that of 6 aromatic carboxylic acids were employed as standard samples to evaluate the CE method from a viewpoint of detection sensitivity. PTH amino acids were concentrated and separated by sweeping micellar electrokinetic chromatography (MEKC) under acidic conditions and only 5-fold increases in sensitivity were obtained for a single run separation of 22 PTH amino acids. The aromatic carboxylic acids were concentrated and separated either under alkaline conditions by capillary zone electrophoresis or under acidic conditions by MEKC. Detection limits of these carboxylic acids were 0.05-0.6ppm.View full abstractDownload PDF (782K) -
Takashi Sazuka2001 Volume 45 Issue 2 Pages 123-128
Published: June 15, 2001
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSThe whole genome sequence of unicellular cyanobacterium Synechocystis sp. strain PCC 6803 was completed in 1996 and nitrogen fixable filamentous cyanobacterium Anabaena sp. strain PCC 7120 is almost completed in our Kazusa DNA Research Institute. We initiated characterization of two organisms from a proteomic viewpoint by exploiting two-dimensional gel electrophoresis coupled with N-terminal protein sequencing. As a result, we succeeded in linking 347 protein spots on two-dimensional gels with the genes encoded on the genome of both species. These results provide us the “protein-gene linkage maps”of two cyanobacteria, which are highly beneficial for functional analysis of cyanobacteria at protein level. Compared two cyanobacterial proteomes with their whole genome sequences, we can extract many items of information concerning their surrounding nucleotide sequences of translation initiation site, rare initiation colons, post-translational processings (including translation initiator methionine processing, signal peptide processing and etc.) concerning to many functionally known and unknown cyanobacterial proteins. In consequence, comparative genomics together with comparative proteomics will serve us very valuable information comprehensive understanding of the molecular basis of cyanobacterial life.View full abstractDownload PDF (8088K) -
Yayoi Kimura, Hisashi Hirano2001 Volume 45 Issue 2 Pages 129-137
Published: June 15, 2001
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSThe post-translational modification of proteasome has been investigated to determine the relation between function and the post-translational modification in the proteasome. The 26S proteasome is a large protein complex with proteolytic activity, consisting of 20S proteasome and 19S regulatory particle. In yeast, there are at least three N-acetyltransferases (NAT), NAT1, MAK3 and NAT3. Among 14 subunits of the 20S proteasome, the α1, α2, α3, α4, α7 and β3 subunits have been found to be N-acetylated with NAT1, the α5 and α6 subunits with MAK3, and the β4 subunit with NAT3. It was shown that chymotrypsin-like activity is slightly higher in the NAT1 deletion mutant than the normal strain, suggesting that N-acetylation be related to the proteolytic activity of 20S proteasome. The N-acetylation of 20S proteasome subunits in plants have been studied. In addition to the N-acetylated subunits in yeast, the β6 subunit has been deduced to be N-acetylated in plants. Similarly, N-terminal modification of the 19S regulatory particle has been investigated in yeast. Among 17 subunits identified in the 19S regulatory particle, 13 have been found to be N-terminally modified and at least 11 to be N-acetylated. On the other hand, phosphorylation is well-known post-translational modification in proteins. The phosphorylated subunits have been identified three in the yeast 20S proteasome and two in the mammal 19S regulatory particle. The relation between the proteolytic activity or assembly and phosphorylation of proteasome has been studied, suggesting that the post-translational modification of proteasome is important for its functions.View full abstractDownload PDF (4222K) -
Tosifusa Toda2001 Volume 45 Issue 2 Pages 139-142
Published: June 15, 2001
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSAfter completion of the Human Genome Project, the main target of the next research has shifted to elucidation of functions of unidentified novel genes. In this situation, expectation for the contribution of proteomic research to the bioinformatics has been getting heavier. The unification of genome database and proteome database may promote an advancement of post-genome researches. All spots of proteins isolated on a 2-D gel pattern can be easily assigned to their own sequence on a chromosome by tblastn search served by NCBI. After the mapping of all 2-D gel spot to genomic DNA, the function of unidentified genes will be thoroughly inquired by proteomic research. Many techniques in proteomics can offer much information about tissue/cell specific expression of the gene products, functional regulation by differentiation and carcinogenesis, intracellular localization, protein-to-protein interaction, and posttranslational modifications. A lot of information gathered by proteomic research may help us to assign a specific function to each protein corresponding to its unidentified gene.View full abstractDownload PDF (2931K) -
Kohzoh Imai2001 Volume 45 Issue 2 Pages 143-148
Published: June 15, 2001
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSMost cancers are genetically unstable and the instability exists at two distinct levels. Microsatellite instability (MIN) is observed at the nucleotide level, resulting in base substitutions or deletions or insertions of a few nucleotides. Chromosomal instability (CIN) is observed at the chromosome level and results in losses and gains of whole chromosomes or large portions. MIN is a characteristic of most hereditary nonpolyposis colorectal cancers (HNPCC). Approximately 15% of sporadic gastric and colorectal cancers also display MIN. Gastrointestinal cancers with MIN accumulate slippage-induced frameshift mutations in target genes such as type II TGFβ receptor and Bax. These cancers also have frequent aberrant DNA hypermethylation of tumor suppressor genes, including DNA mismatch repair gene hMLH1. A frequent loss of imprinting (LOI) of the insulin like growth factor II gene has been reported in colorectal cancers with MIN. On the other hand, mechanisms underlying CIN are beginning to be characterized. A small fraction of colorectal cancers have been shown to have mutations of the mitotic-checkpoint gene hBUB1 or hBUBR1. Cancers with MIN and those with CIN have been shown to exhibit fundamental differences in clinical, pathological, and molecular characteristics. From biological and clinical points of view, it is important to characterize the genetic instability of given tumors.View full abstractDownload PDF (957K) -
Tadao Funato, Shinichi Fujimaki, Junko Satoh, Kanoko Kozawa, Mitsuo Ka ...2001 Volume 45 Issue 2 Pages 149-152
Published: June 15, 2001
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSRapid advances in the field of molecular genetics have led to the need for a analytical assay. A number of methods have devised for this purpose, a material used the most widely is used the leukocytes DNA. In this study, we have reported the cases of three types. First, we found the cases who were heterozygotes for adenine phosphoribosyltransferase (APRT) gene mutations with APRT deficiency. Second, we evaluated the usefulness of a real-time reversed transcriptase polymerase chain reaction (RTPCR) system to detect minimal residual diseases. This method was applied a case who had t (8; 21) chimeric transcript in peripheral blood. Third, we evaluated a method to determine human cytomegalovirus (CMV) DNA levels in blood cells in a case transplaned liver. Thus, these methods were indicated possible applications for analysis using blood leukocytes.View full abstractDownload PDF (2989K) -
Naotaka Hamasaki2001 Volume 45 Issue 2 Pages 153-157
Published: June 15, 2001
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSBy using a screening program to clarify the etiology of thrombophilia, we found protein S deficiency, either congenital or acquired, to be an important pathogenesis of thrombosis in the Japanese population. A gene analysis revealed that about one third of the patients with a low protein S activity are associated with varied mutations in the PROS 1 gene. Protein S (PS) is a nonenzymatic cofactor for activated protein C (APC) and plays an integral role as a regulator of APC that inhibits coagulation by enzymatically cleaving the activated forms of factor V and factor VIII. Approximately 60% of plasma PS circulates as a complex with C4b binding protein (C4BP), while the remainder circulates as free PS. Since only free PS has APC cofactor activity, a reduction in free PS is considered to be a cause of plasma PS deficiency. Factor V Leiden (R506Q) is resistant to the protein C/protein S anticoagulant pathway and is found in 20% to 60% of Caucasian patients with venous thrombosis. In Japan, no thrombotic patient having the factor V Leiden gene has been observed, instead, the decreased PS activity was found with a high incidence in thrombotic patients.View full abstractDownload PDF (732K) -
Estimation of lipoprotein particle size and its clinical applicationGen Yoshino, Tsutomu Hirano, Tsutomu Kazumi2001 Volume 45 Issue 2 Pages 159-164
Published: June 15, 2001
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSIncreased frequency of small, dense LDL is associated with the risk of coronary heart disease (CHD). Possible mechanisms include increased susceptibility of small, dense LDL to oxidation and its high affinity for LDL-receptor-independent cell surface binding sites. Although more than 30% of adult men in USA has been reported to have small, dense LDL, only 5.4% of young Japanese men had small, dense LDL. However, more than 70% of Japanese subjects with CHD had small, dense LDL, indicating a clinical importance of LDL size in the development of CHD in Japan. Furthermore, almost half of obese women (BMI>35kg/m2) had small, dense LDL. Our previous observation revealed that type 2 diabetics had smaller LDL even if they were apparently normolipidemic. There was also a close relationship between LDL size and plasma triglyceride even in the population with normotriglyceridemia, which may suggest that the plasma triglyceride is“the lower the better”from the stand point of LDL size. Finally, weight reduction of obese women by strict diet control, treatment of diabetics by acarbose or troglitazone and treatment of hyperlipidemia by a new statins, fluvastatin, were all successful in increasing LDL size associated with decreased plasma triglyceride.View full abstractDownload PDF (1087K)
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