December 31, 2009


Dear Friends and Colleagues,


Thank you for your interest in our PR-CALC software.


Several weeks ago, we received a letter from the State University of New York Research Foundation alleging that PR-CALC infringes US patent 6,831,459, awarded to Thomas Szyperski et al. and entitled, “Method of using G-matrix Fourier transformation nuclear magnetic resonance (GFT NMR) spectroscopy for rapid chemical shift assignment and secondary structure determination of proteins.”  This letter threatened litigation if we do not stop distributing the software immediately.


After a detailed analysis of this patent, we do not believe that our work infringes it, and there are reasons to question the patent’s validity based on published literature prior to the patent.  However, it has become apparent that the only way to defend our position would be to go to court, and it is sadly beyond our limited financial resources to do so.  Therefore it is with regret that we announce that PR-CALC will no longer be available to the NMR community.


Sincerely yours,


Brian E. Coggins, Ph.D.

Pei Zhou, Ph.D.