Team:Aberdeen Scotland/Curve Fitting

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<p>Note that the R-square value is close to one which suggests that the fit of the curve to the data is very good.
<p>Note that the R-square value is close to one which suggests that the fit of the curve to the data is very good.
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The Hill coefficient is estimated to be 1.302 with a lower limit of 1.135 and an upper limit of 1.469. However, this is just for one MS2 stem loop and we have two. Multiplying this value by 2 we get 2.604 with a lower limit of 2.270 and an upper limit of 2.938. A value greater than 2 suggests that a protein binding to the first stem loop will make it easier for a protein to bind to the second stem loop. We say that co-operativity has been increased.
The Hill coefficient is estimated to be 1.302 with a lower limit of 1.135 and an upper limit of 1.469. However, this is just for one MS2 stem loop and we have two. Multiplying this value by 2 we get 2.604 with a lower limit of 2.270 and an upper limit of 2.938. A value greater than 2 suggests that a protein binding to the first stem loop will make it easier for a protein to bind to the second stem loop. We say that co-operativity has been increased.
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Therefore, we have n<sub style="font-size:10px">1</sub>=2.6 and n<sub style="font-size:10px">2</sub>=1.  
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Therefore, we have n<sub style="font-size:10px">1</sub>=2.6 and n<sub style="font-size:10px">2</sub>=1. </p>
<h3>What Does This Mean in Terms of Parameter Space Analysis?</h3>
<h3>What Does This Mean in Terms of Parameter Space Analysis?</h3>

Revision as of 14:12, 20 October 2010

University of Aberdeen - ayeSwitch - iGEM 2010

Curve Fitting to find the Hill Coefficient for the GFP/Bbox-stem Association (n2)

Based on a graph in a paper by Witherell et al.[14] which showed the binding curves of the MS2 stem loop we could calculate more accurately the value for n1. Our two MS2 stem loops (see Fig 1 in Equations) are 19 nucleotides apart, so our binding curve will most closely resemble that of the 8-16 construct, shown in figure 5A (filled squares).




Figure 5. A. Graph from paper by Witherell et al.[14] showing the binding curves of the MS2 stem loop. The filled squares are the 8-16 construct
which closely resembles the binding curves of our MS2 stems. B. The binding curve for the 8-16 construct was reproduced in MATLAB and the Hill
function for activators equation fitted to it (red line).



The curve fitting tool gave the following estimated parameters for β(a), K(b) and n(c):



Note that the R-square value is close to one which suggests that the fit of the curve to the data is very good.

The Hill coefficient is estimated to be 1.302 with a lower limit of 1.135 and an upper limit of 1.469. However, this is just for one MS2 stem loop and we have two. Multiplying this value by 2 we get 2.604 with a lower limit of 2.270 and an upper limit of 2.938. A value greater than 2 suggests that a protein binding to the first stem loop will make it easier for a protein to bind to the second stem loop. We say that co-operativity has been increased.

Therefore, we have n1=2.6 and n2=1.

What Does This Mean in Terms of Parameter Space Analysis?