TABLE 1.

Comparison of dissociation constants for several receptor-ligand pairs^a

Analyte	Immobilized receptor	KD (M)	Reference
HHV-8 K8.1-Fc	Heparin	4.8 × 10−8
HIV-1 soluble gp120	Heparin	5.5 × 10−8	36
HSV-2 soluble gB	Heparin	7.7 × 10−7	56
HSV-1 soluble gD	HveA	3.2 × 10−6	57
aFGF	Heparin	9.5 × 10−8	31
Biotin	Streptavidin	10−15	BIAcore

^aThe K_D of soluble K8.1 and heparin was calculated from kinetic data (K_D = k_off/k_on) obtained in SPR experiments using heparin-coated biosensor chips. A simple one-to-one reaction (Langmuir model) was used for the calculation. This model fitted sufficiently to the data, as can be concluded from the low χ² values (0.118 to 0.168). HIV-1, human immunodeficiency virus type 1; aFGF, acidic fibroblast growth factor; HveA, herpesvirus entry mediator A.