From: christopher chin <chinchiquei@yahoo.com>
  To  : James W Bryson <brysonj@bms.com>
  Date: Mon, 10 May 1999 09:43:32 -0700 (PDT)

Re: Compare fitting program for Ka

James,
You are absolutely correct.  Thank you for pointing
out speed correction factor to me.  After I made the
speed correction, there is no discrepancy between
Beckman and WinNonlin.  Both give tetramer as the
likely model.  Also the discrepancy between Beckman
and WinNonlin has dropped from 30% to 8-10%. 

Best regards,
chris 



--- James W Bryson <brysonj@bms.com> wrote:
> Chris,
> 
> Here's one potential source for the difference you
> observed
> between Origin and WinNonLin in the 9-data set
> global fit:
> the speed factors you have quoted on at the end of
> the document
> "compare programs.doc" are incorrect.  The speed
> factor is
> (speed_2/speed_1)^2, i.e. the square of the ratio of
> the speeds.
> Thus if you are defining 18krpm with speed factor =
> 1.0,
> then 20krpm would be (20/18)^2 = 1.23457, and 24krpm
> would
> be 1.77778.  See if this helps.  This may remove the
> discrepency
> in the dimer vs. trimer vs. tetramer problem as well
> if you calculated
> the speed factors similarly for the WinNonLin fits. 
> I hope this helps.
> 
> Best Regards,
> -Jim
> 
> ________________________
> James W. Bryson.
> Bristol-Myers Squibb Co.
> BrysonJ@BMS.com
> 609-252-5467
> 
> 
> 
> 
> 
> 
> 

===
-------------------------------------
Christopher Chin
Manager
Sealy Center for Structural Biology
HBC&G, 5136 MRB. rt1055 UTMB
cchin@utmb.edu, 409-772-1693, efax 708-585-1920