The specific activity of adenylate cyclase in membrane preparations obtained from Rous Sarcoma virus-transformed chicken embryo fibroblasts is two to four times lower than that found in untransformed membranes. Adenylate cyclase was solubilized from normal and transformed membranes in order to evaluate the influence of the membrane phase on the properties of the enzyme. Adenylate cyclase in normal and transformed membranes differed in specific activity, V for ATP, activation entropies, sensitivity to Ca2+, and stability at 37°C. Solubilization with Brij 96 abolished or greatly reduced these differences. These data suggest that the differences between adenylate cyclase activities in normal and transformed chichen embryo fibroblasts are due either to differential modulation of enzyme activity by an effector which requires intact membranes for its effects, or indirect effects due to altered membrane properties.
Bibliographical noteFunding Information:
We wish to expresso ur appreciatiotno RebeccaK uceraa nd BarbaraL arrain for their skillful technicaal ssistanceT.h is work was supportedb y a grant from the WashingtonH eart AssociationN, ationalScience FoundationG rant PCM 73-001245a, nd ResearchC areerD evelopmenAtw ard A100120 to D.R.S. and National CancerG rantCA 12467a nd ResearchC areerD evelopmenAtw ard CA 00092 to M.J.W. One of us (W.A.T.) was supportedb y National Instituteso f Health PostdoctoraFle llowshipF 32 GM 06875-01S. .G. is a NationalI nstitutes of HealthP redoctoraTlr ainee.
- (Chicken embryo fibroblast)
- Adenylate cyclase
- Rous sarcoma virus
- Viral transformation