Enzyme kinetics software for Windows

Martin Pion mpion at ARTSCI.WUSTL.EDU
Sat Oct 28 23:51:19 EST 1995

Dr. Peter Gegenheimer gave Enzfitter a nice plug, for which Biosoft is
grateful. Just one thing, though. It's not $395, as he wrote, but only $299
- so might as well buy two while you're at it. Give the second to a friend
for Christmas.

Sincerely,   Martin..

Martin Pion, Biosoft, PO Box 10938, Ferguson, MO 63135.
Tel: 314 524 8029  Fax: 314 524 8129


At 8:45 PM 10/27/95, pgegen at rnaworld.bio.ukans.edu wrote:
>In <46ovj1$n5e at ixnews3.ix.netcom.com>, jsalb at ix.netcom.com (Jesse Salb) writes:
>>Anyone know of enzyme kinetics software for Windows which will do
>>Lineweaver Burk plots and is very flexible with respect to plot
>>appearance? I'm using Grafit now but it's highly user unfriendly,
>>though admittedly very flexible if you want to spend a few years
>>learning it.
And Dr. Peter Gegenheimer wrote back:
>First, for anyone looking, you DON'T do Lineweaver-Burk plots to get
>kinetic parameters. (I'm sure Jesse is using GrafIt to do least squares
>non-linear curvefitting.) SECOND, GrafIt is a Win version of Enzfitter, an
>old DOS program available from BioSoft (Missouri, USA) and via the Sigma
>catalogue. They both originated from Robin Leatherbarrow, an old-line
>kineticist. Enzfitter defines the category of enzyme kinetics software.
>Clunky, DOS-based, doesn't do publication-quality output, BUT is easier to
>use f
>or basic curvefitting than any other program on the market. I'm not aware
>of any program that has a better command of non-linear curvefitting. For
>example, Enzfitter allows you to choose all possible weighting methods,
>not just one or two, including weighting by 1/y; 1/(y^2) for cpm data, and
>weighting by direct use of std. dev. of each data point. Enzfitter makes
>it easy to plot resaidualls, etc. Best of all, Enzfitter is unique (except
>for GrafIt) in that if the equation you're trying to fit can be linea
>rized, Enzfitter automatically does so, uses least-squares regression
>(which doesn't require any initial estimates of parameters) to calculate
>the initial estimates, and then feeds those estimates into the
>Marquardt-Levenburg non-linear regression procedure (all non-linear
>methods require initial estimates of the final values).
>SO, why try anything else? Well, Enzfitter still costs $395 (certainly was
>worth it to me, though); doesn't do publicaiton graphs, and can't save the
>graphs. It's a calculation tool.  [snipped]

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