How can I divide my fitted curve by the determined coefficient in order to normalize it?

I have determined a curve of best fit using the fittype, fitoptions and fit functions, however I would like to divide my curve by one of the determined coefficients in order to normalize it for comparative purposes. I unfortunately have no idea how to do this. An example of my code can be seen below.

if true
xasp=[0;30;60;120;180;240;300;360;495;600];
yasp=[0;0.2872;0.5607;0.5232;1.0856;1.1968;1.5946;1.8525;2.3285;2.7937];
ft=fittype(@(a,c,x)a*(1-exp(-x*c)));
Fasp=fitoptions('method','NonlinearLeastSquares','Lower',[0,0],'Upper',[4,6],'StartPoint',[4,0.5]);
[curveasp,gofasp]=fit(xasp,yasp,ft,Fasp)

end

This gives the following result:

if true
  curveasp = 

     General model:
     curveasp(x) = a*(1-exp(-x*c))
     Coefficients (with 95% confidence bounds):
       a =           4  (2.143, 5.857)
       c =    0.001743  (0.0005611, 0.002925)
gofasp = 

           sse: 0.1579
       rsquare: 0.9791
           dfe: 8
    adjrsquare: 0.9765
          rmse: 0.1405
  end

I know that I can save the value of 'a' by saying a=curveasp.a however I would like to divide my curve by the value of 'a' so that the new curve is just given by y=1-exp^-(cx) instead of y=a(1-exp^-(cx)), but cannot seem to figure out how to do it.

Any help would be appreciated.