Mise en evidence d'un recepteur d'UDP‐glucose dans les membranes microsomiques des hepatocytes de rat

摘要

>Rat liver microsomal membranes have been shown to contain a biosynthetic pathway of UDP-glucose. In addition, they are able to bind UDP-glucose in a reversible manner. As UDP-glucose is also metabolized in these membranes, the study of the binding has been performed with a microsomal Triton X 100 extract. This reversible binding depends on pH (maximum at pH 8.1) and manganous ions, and disappears at pH 6.5. It exhibits a high affinity (K_diss = 3 μM), and a narrow specifity for UDP-glucose. Proteolytic digestion inhibits the binding up to 90%, showing that the UDP-glucose receptor has a proteic nature. These binding characteristics have been also found in the membranes themselves, indicating that the detergent solubilization does not destroy the protein binding capacity.