TY - JOUR

T1 - Binding of anandamide to bovine serum albumin

AU - Bojesen, I.N.

AU - Hansen, Harald S.

PY - 2003

Y1 - 2003

N2 - The endocannabinoid anandamide is of lipid nature and may thus bind to albumin in the vascular system, as do fatty acids. The knowledge of the free water-phase concentration of anandamide is essential for the investigations of its transfer from the binding protein to cellular membranes, because a water-phase shuttle of monomers mediates such transfers. We have used our method based upon the use of albumin-filled red cell ghosts as a dispersed biological "reference binder" to measure the water-phase concentrations of anandamide. These concentrations were measured in buffer (pH 7.3) in equilibrium with anandamide bound to BSA inside resealed human red cell membranes at low molar ratios below one. Data were obtained at 0°C, 10°C, 23°C, and 37°C. The equilibrium dissociation constant (K ) increases with temperature from 6.87 ± 0.53 nM at 0°C to 54.92 ± 1.91 nM at 37°C. Regression analyses of the data suggest that BSA has one high-affinity binding site for anandamide at all four temperatures. The free energy of anandamide binding (¿G) is calculated to -43.05 kJ mol with a large enthalpy (¿H ) contribution of -42.09 kJ mol. Anandamide has vasodilator activity, and the binding to albumin may mediate its transport in aqueous compartments. - Bojesen, I. N., and H. S. Hansen. Binding of anandamide to bovine serum albumin.

AB - The endocannabinoid anandamide is of lipid nature and may thus bind to albumin in the vascular system, as do fatty acids. The knowledge of the free water-phase concentration of anandamide is essential for the investigations of its transfer from the binding protein to cellular membranes, because a water-phase shuttle of monomers mediates such transfers. We have used our method based upon the use of albumin-filled red cell ghosts as a dispersed biological "reference binder" to measure the water-phase concentrations of anandamide. These concentrations were measured in buffer (pH 7.3) in equilibrium with anandamide bound to BSA inside resealed human red cell membranes at low molar ratios below one. Data were obtained at 0°C, 10°C, 23°C, and 37°C. The equilibrium dissociation constant (K ) increases with temperature from 6.87 ± 0.53 nM at 0°C to 54.92 ± 1.91 nM at 37°C. Regression analyses of the data suggest that BSA has one high-affinity binding site for anandamide at all four temperatures. The free energy of anandamide binding (¿G) is calculated to -43.05 kJ mol with a large enthalpy (¿H ) contribution of -42.09 kJ mol. Anandamide has vasodilator activity, and the binding to albumin may mediate its transport in aqueous compartments. - Bojesen, I. N., and H. S. Hansen. Binding of anandamide to bovine serum albumin.

UR - http://www.scopus.com/inward/record.url?scp=0141794223&partnerID=8YFLogxK

U2 - 10.1194/jlr.M300170-JLR200

DO - 10.1194/jlr.M300170-JLR200

M3 - Journal article

AN - SCOPUS:0141794223

VL - 44

SP - 1790

EP - 1794

JO - Journal of Lipid Research

JF - Journal of Lipid Research

SN - 0022-2275

IS - 9

ER -