Resolution:
## Figure 1.
Equations for the binding models are based on the law of mass action and conservation
of mass. Two mass action equations (c)-(d) for dissociation constants derived from (a)-(b)
and three conservation of mass equations (e)-(g) formed the five equations solved
simultaneously for the two sites model_{total }for saturation binding. Four mass action equations for dissociation constants derived
from (i)-(l) and four conservation of mass equations (m)-(p) formed the eight equations
solved simultaneously for the two sites model_{total }for homologous or heterologous competition. L was the independent variable for two
sites model_{free }for saturation binding, which did not include Eq. (g). B was the independent variable
of two sites model_{free }for competition, which did not include Eq. (p). One site model_{total }excluded terms referring to the second site. The two sites model for saturation binding
that ignored ligand depletion was based on Eqs. (c)-(f) and assumed LT = L. Notation:
α_{L }= constant describing NSB of radioligand; K_{d1 }= dissociation constant of high affinity binding site; L = free radioligand; LT =
total radioligand; NSB_{L }= nonspecific binding of radioligand; R1 = unbound first binding site; R1L = radioligand
bound to first site; R1T = total high affinity binding site; B = free competitor (blocker).
With analogous notations, the index "2" in these equations refers to the low affinity
binding site.
Person and Wells |