DNA simulation with reduced phosphate charge

[Wen-shyong Tzou]

Dear Modellers:

	I am doing a simulation of DNA. I am going to use solvent 
approximation (dielectric constant epsilon = r) and reduced charge of
phosphate group. For the reduced charge of phosphate, I can only find a paper
titled "NMR studies and restrained-molecular-dynamics calculations of a long 
A+T-rich stretch in DNA. Effects of phosphate charge and solvent 
approximations" appearing in Eur. J. Biochem vol 234, p832-842 (1995). In 
that paper, phosphate group charge is reduced from -1.2e to -0.32e. Can
somebody suggest me on the theoretic basis of charge reduction or similar 
readings about this method ?

	Thank you very much for your help

	Wen-Shyong Tzou


       |                  Wen-Shyong Tzou
       |           /~~\   Ph.D. candidate
       | *        /   /   Laboratory for Computer Modeling of Biomolecules
       /         /    \	  Institute of Biomedical Sciences
      /         /      \  Academia Sinica,Nankang
     / *       /       |  Taipei, Taiwan, R.O.C.
    /         /        |  Address: P.O. Box 1-99, Nankang, Taipei, Taiwan
   /         |        /  
  /     <*>  |       |    e-mail: wstzou at sinica.edu.tw
  |          \      /     Phone: (886)-2-27899033
  /           \    /      Fax:   (886)-2-27887641
_/             |  /
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