巻号一覧
28 巻 (2001)
- 5 号 p. 200-
- 4 号 p. 164-
- 3 号 p. 106-
- 2 号 p. 54-
- 1 号 p. 2-
28 巻, 2 号
選択された号の論文の10件中1～10を表示しています
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古賀 邦正, 平岡 伸一, 金 英樹, 萩原 大輔, 末廣 康孝, 坂本 泰子, 高橋 克忠2001 年 28 巻 2 号 p. 54-61
発行日: 2001/03/31
公開日: 2009/09/07
ジャーナル フリー微生物代謝熱計測法を用いて,野菜畑地土,海岸砂地土壌,山地土壌,グランド土壌,茶畑土壌それぞれの有機物変換能を評価した。その結果,以下のことが明らかになった。(1)微生物代謝熱計測法によって土壌による有機物の分解速度の違いが再現性よく把握できる。(2)土壌の種類によって有機物の分解速度が大きく異なっている。(3)野菜畑地土壌及び海岸砂地土壌は有機物分解速度がきわめて早い。(4)茶畑土壌は有機物分解能が他の土壌に比べて遅い。(5)この評価法を用いることによって有機物分解能が非常に強い高機能土壌の開発や有機物肥料の有効利用法の開発が可能と考えられる。抄録全体を表示PDF形式でダウンロード (1755K) -
木村 隆良, 深田 はるみ, 児玉 美智子2001 年 28 巻 2 号 p. 62
発行日: 2001/03/31
公開日: 2009/09/07
ジャーナル フリーPDF形式でダウンロード (129K) -
Ingemar Wadsö2001 年 28 巻 2 号 p. 63-67
発行日: 2001/03/31
公開日: 2009/09/07
ジャーナル フリーThe importance of uniform terminology and standardised chemical calibration and test processes for titration microcalorimetry are discussed. Calorimeters are normally calibrated electrically, but in the case of microcalorimeters, results from such calibration experiments can easily lead to significant systematic errors. The quality of results will often improve if a chemical calibration technique is used. In order to test the properties of a calorimeter and to validate the results, it is important to have available suitable test reactions. References are given to some standardised chemical calibration and test processes for titration microcalorimetry.抄録全体を表示PDF形式でダウンロード (1294K) -
Adrian Velazquez-Campoy, Irene Luque, Ernesto Freire2001 年 28 巻 2 号 p. 68-73
発行日: 2001/03/31
公開日: 2009/09/07
ジャーナル フリーIsothermal Titration Calorimetry (ITC) plays a central role in the characterization and optimization of lead compounds as viable drug candidates. ITC is the only technique that permits a complete experimental characterization of the binding affinity of a ligand in terms of its thermodynamic components ΔG, ΔH, ΔS and ΔCp. In addition, ITC is ideally suited to characterize coupled processes like protonation/deprotonation reactions. One of the major challenges for ITC has been the analysis of ligands with high binding affinities. This issue becomes a serious problem in drug design, where one of the main goals is to optimize the binding affinities of lead compounds to nanomolar or subnanomolar levels. These binding affinities have been traditionally considered to be beyond the useful range of calorimetric analysis. In this paper we will discuss the implementation of ITC experimental designs aimed at characterizing very high affinity binding processes (Ka > 109M-1) and apply them to the characterization of HIV-1 protease inhibitors. We will also discuss the characterization of protonation/deprotonation coupling to the binding reaction.抄録全体を表示PDF形式でダウンロード (1275K) -
城所 俊一2001 年 28 巻 2 号 p. 74-82
発行日: 2001/03/31
公開日: 2009/09/07
ジャーナル フリーQuantitative evaluation of catalytic activity of enzymes against various substrates under several solution conditions is important to understand the catalytic mechanism. In this paper, the titration calorimetry was applied to evaluate the catalytic activity of a protease not only in the condition of peptide digestion but also in that of peptide synthesis. Two calorimetric observables, the compensation power and its integrals can be determined directly and precisely by titration calorimetry. In the hydrolytic condition, a calorimetric Lineweaver-Burk plot and non-linear least-squares method with these two observables were found to be effective to determine the enzymatic parameters precisely. Moreover, the enthalpy change accompanying the catalytic reaction can be determined with no information on the enzyme concentration and initial substrate concentration by this method with comparing the results of spectroscopic method. In the synthetic condition where the spectroscopic method can not be applied practically, the catalytic activity of the enzyme was shown to be determined quantitatively by titration calorimetry. The feature of direct observation of the reaction rate by calorimetry is considered to give us an effective and precise way to evaluate the protease activity.抄録全体を表示PDF形式でダウンロード (1518K) -
鳥越 秀峰2001 年 28 巻 2 号 p. 83-90
発行日: 2001/03/31
公開日: 2009/09/07
ジャーナル フリーTo understand the mechanism of affinity maturation, the antigen-antibody interactions between 4-hydroxy-3-nitrophenylacetyl caproic acid (NP-Cap) and the Fab fragments of three anti-4-hydroxy-3-nitrophenylacetyl (NP) antibodies, N1G9, 3B44, and 3B62, were examined by isothermal titration calorimetry. The analyses revealed that all of these interactions were mainly driven by negative changes in enthalpy. The enthalpy changes decreased linearly with temperature in the range of 25∼45°C, producing negative changes in heat capacity. On the basis of the dependency of binding constants on the sodium chloride concentration, it was shown that, during the affinity maturation of the anti-NP antibody, the electrostatic effect did not significantly contribute to the increase in the binding affinity. It was also found that, as the logarithm of the binding constants increased during the affinity maturation of the anti-NP antibody, the magnitudes of the corresponding enthalpy, heat capacity, and unitary entropy changes increased almost linearly. On the basis of this correlation, it is concluded that, during the affinity maturation of the anti-NP antibody, a better surface complementarity is attained in the specific complex to obtain a higher binding affinity.抄録全体を表示PDF形式でダウンロード (1585K) -
油谷 克英, 小笠原 京子2001 年 28 巻 2 号 p. 91-97
発行日: 2001/03/31
公開日: 2009/09/07
ジャーナル フリーA characteristic property of the tryptophan synthase α2β2 complex is the mutual activation of the α and β subunit upon complex formation. It has been speculated that this mutual activation results from the conformational change due to the α/β subunit interaction. In order to elucidate this mechanism, the association for the various combinations of the α and β subunits from mesophiles, Escherichia coli and Salmonella typhimurium, and for the two subunits from a hyperthermophile, Pyrococus furiosus, was examined using isothermal titration calorimetry. In mesophile proteins, the analyses of the thermodynamic parameters of association indicate that both the α and β subunits fold coupled with the association and the folding might occur not only at the subunit contact surface but also at the other parts in the molecules. This conformational rearrangement might be the origin of mutual activation. The thermodynamic measurements also revealed that the substitution of only one residue in the subunit interface of the E. coli α subunit changed the thermodynamic properties of association with the β subunit similar to those of the S. typhimurium α subunit. On the other hand, the association between α and β2 subunit from P. furiosus was characterized by substantially low values of association enthalpy and association heat capacity changes. This suggests that the folding coupled with the association decreases at low temperatures around 40°C examined. This relates with remarkably low activities around 40°C, as compared with those of mesophile proteins. These differences in thermodynamic properties were discussed on the basis of X-ray structures of both proteins.抄録全体を表示PDF形式でダウンロード (1114K) -
2001 年 28 巻 2 号 p. 98
発行日: 2001/03/31
公開日: 2009/09/07
ジャーナル フリーPDF形式でダウンロード (196K) -
石室 良孝, 高橋 秀明2001 年 28 巻 2 号 p. 99-100
発行日: 2001/03/31
公開日: 2009/09/07
ジャーナル フリーPDF形式でダウンロード (304K) -
2001 年 28 巻 2 号 p. 104
発行日: 2001年
公開日: 2009/09/07
ジャーナル フリーPDF形式でダウンロード (128K)
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