Proceedings of the Japan Academy, Series B
Online ISSN : 1349-2896
Print ISSN : 0386-2208
ISSN-L : 0386-2208
Volume 70, Issue 4
Displaying 1-2 of 2 articles from this issue
  • Akikazu MATSUMOTO, Takayuki OTSU
    1994 Volume 70 Issue 4 Pages 43-47
    Published: 1994
    Released on J-STAGE: October 13, 2006
    The radical polymerization of dialkyl fumarates bearing various ester alkyl groups was investigated to evaluate the propagation and termination rate constants (kp and kt) by means of electron spin resonance spectroscopy. It was revealed that the introduction of tert-butyl ester group promoted the polymerization reactivity not only the retardation of the termination, but also by the acceleration of the propagation despite of steric repulsion by the bulky substituents. The latter was interpreted by the stereospecific propagation leading to the diisotactic polymer formation.
    Download PDF (474K)
  • Kyoko YOKOTA, Yoichi YAZAWA, Shun NAKAMURA
    1994 Volume 70 Issue 4 Pages 48-52
    Published: 1994
    Released on J-STAGE: October 13, 2006
    We have purified adenosine triphosphate: arginine phosphotransferase (EC2-7-3-3, arginine kinase) and molecularly cloned the cDNA from the tail muscle of crayfish, Procambarus clarkii. An open reading frame encodes 357 amino acid residues with a calculated molecular mass of 40, 118 dalton. The predicted amino acid sequence shows 60% similarity with that of human creatine kinase B-subunit. The expression of a full-length cDNA in COS7 cells gave rise to a product of 40kDa and conferred the arginine kinase activity on mammalian cells. The amino acid sequence surrounding cys271 is well conserved as an active site for the catalytic function among a family of phosphagen kinase. We have found that chemical modification of a single cysteinyl residue of arginine kinase inhibits the enzymatic function and ATP protects the enzyme against this modification.
    Download PDF (629K)