Option for changing distance between plot guide and axis

A very simple example of why I am interested in this should explain my problem properly:

hill(x,v,K,n) = v*(x^n)/(x^n+K^n)
plot([1.,1.],[-0.05,0.5],lw=2,linestyle=:dot,color=:black,label="")
plot!([0.0,1.],[0.5,0.5],lw=2,linestyle=:dot,color=:black,label="")
plot!(x->hill(x,1.,1.,2),0,5,label="n = 2",lw=3)
plot!(x->hill(x,1.,1.,5),0,5,label="n = 5",lw=3)
plot!(x->hill(x,1.,1.,10),0,5,label="n = 4",lw=3)
plot!(legend=:bottomright,xlimit=(0.,4.),ylimit=(-0.025,1.05),legendfontsize=10,xticks=[],yticks=[],xguide="Activator",yguide="hill(acitvator)",leftmargin=3mm)
annotate!([(1,-0.07,"K"),(-0.13,0.5,"v/2")]) 

creates this plot:
image

Now there’s obviously a problem here. Is there some option where I can change the distance between the y axis and the guide (so that “hill(activator)” doesn’t write over “v/2”)?