# goldbeter model Proc Roy Soc B 261:319-324
#
m'=nus*1/(1+(pn/ki)^n)-num*m/(km+m)
p0'=ks*m-v1*p0/(p0+k1)+v2*p1/(p1+k2)
p1'=v1*p0/(p0+k1)+v4*p2/(k4+p2)-v2*p1/(k2+p1)-v3*p1/(k3+p1)
p2'=v3*p1/(k3+p1)-v4*p2/(k4+p2)-kk1*p2+kk2*pn-nud*p2/(kd+p2)
pn'=kk1*p2-kk2*pn
par nus=.76,num=.65,km=.5,ks=.38,nud=.95
par kk1=1.9,kk2=1.3,ki=1,kd=.2,n=4
par k1=2,k2=2,k3=2,k4=2
par v1=3.2,v2=1.58,v3=5,v4=2.5
# total protein
aux pt=p0+p1+p2+pn
# 
init m=0.6,p0=.4,p1=.4,p2=.5,pn=.8
@ total=72
@ meth=qualrk,tol=1e-6
@ xhi=72,ylo=0,yhi=6,yp=pt
done