Seibutsu Butsuri
Online ISSN : 1347-4219
Print ISSN : 0582-4052
ISSN-L : 0582-4052
Volume 14 , Issue 2
Showing 1-4 articles out of 4 articles from the selected issue
  • Tsuneo OKUBO
    1974 Volume 14 Issue 2 Pages 45-55
    Published: March 25, 1974
    Released: May 25, 2009
    JOURNALS FREE ACCESS
    The recent advancement in the study on the catalytic influences of polyelectrolytes was reviewed with 73 references. Polyelectrolyte influence (both acceleration and deceleration) on ionic reactions, which is much larger than the simple electrolyte effect, is explained with the changes of the rate constant induced by high electrostatic potentials of macroions. The quantitative discussion is carried out by using the Lifson-Katchalsky and Manning theories for the dilute polyelectrolyte solutions. In addition to the electrostatic interactions, the contributions of hydrophobic, hydrogen-bonding and charge-transfer interactions are dissected for a variety of combinations of "catalyst" polyelectrolytes and reactants. Polyelectrolyte influence on elementary processes is discussed for equilibrium reactions. The forward and backward steps are affected in a different proportion; the use of the term "polyelectrolyte catalysis" is not justified. The polyelectrolyte acceleration of interionic reactions is shown to be associated with decreases in the entropy and enthalpy of activation. The desolvation of the ions by the electrostatic field of macroions is discussed.
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  • Takahiro MASUDA
    1974 Volume 14 Issue 2 Pages 56-65
    Published: March 25, 1974
    Released: May 25, 2009
    JOURNALS FREE ACCESS
    The present article outlines the recent development of pulse radiolysis studies on aqueous solutions of enzyme proteins.
    Pulse radiolysis method has provided much information on fast process induced by a short-lived perturbation of various substances. In recent few years, the results from an application of the method to aqueous solutions of biological macromolecules have been increasingly accumulated. Particularly an extensive work on enzyme proteins reveals that protein molecule reacts with the primary radicals produced in radiolysis of water to give a characteristic transient absorption and above 1010M-1sec-1 is determined as a rate constant for the reaction. Studies on selective reactions of inorganic radical anions with proteins suggest that radiation chemical technique could provide a new method for investigation of molecular nature of biological substances. Finally the reactivity of protein towards OH radicals is discussed in terms of tertiary structure of the protein molecule.
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  • Kuniaki NAGAYAMA
    1974 Volume 14 Issue 2 Pages 66-78
    Published: March 25, 1974
    Released: May 25, 2009
    JOURNALS FREE ACCESS
    A number of experiments have been performed on the kinetics of the helix-coil transition of polypeptides and the reported results are devided into two classes: "fast" and "slow".
    Schwarz calculated the kinetic characteristics of the transition taking into account of the nucleation and propagation process in the formation of the helical structure and arrived at the expectation of the relaxation time which time which falls in submicro second range even at the transition midpoint.
    Experiments performed by temperature jump techniques, dielectric dispersion and ultrasonic methods have supported above expectation and all of them measure times of the order of 10-7sec.
    On the other hand relaxation times, as measured by NMR, are reported to be greater than 10-2sec which are derived from the analysis of the double peak in NMR spetra seen near the transition midpoint.
    What is the reasen of this discrepancy between fast and slow relaxation times? We review this problew focussing our attention to the NMR experiments and examine the background of this contradiction.
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  • [in Japanese], [in Japanese]
    1974 Volume 14 Issue 2 Pages 80-84
    Published: March 25, 1974
    Released: May 25, 2009
    JOURNALS FREE ACCESS
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