Water Soluble Receptors for Human Growth Hormone from Rabbit Liver

摘要: AbstractSoluble receptors that bind human growth hormone have been prepared by incubation of liver membranes from pregnant female rabbits in 1 mM Tris buffer (pH 7.5 or 9.0) at 4°C. Up to 29% the binding sites could be solubilized within 48 hours. The kinetics soluble receptor, hormonal specificity and parameters calculated Scatchard analysis (Ka 2.2 × 109 M-1, capacity 409 fmole/mg) were essentially unchanged compared with those for parent membrane-associated (particulate) receptor. Gel filtration on Ultrogel AcA22 indicated major peak eluted a molecular weight 300,000 daltons. Specificity studies showed had moderately high affinity ovine prolactin ∼1 108 M-1), but negligible insulin. Although aqueous extraction gives lower yield than detergent extraction, it nevertheless avoids some problems as...