Identification of selenoproteins in the endoplasmatic reticulum of the rat kidney by combination of radioanalytical techniques and biochemical methods

Investigations have been carried out on rats to obtain information about the selenium-containing proteins present in the microsomal fraction and especially in the endoplasmatic reticulum (ER) of the kidney. For the determination of the selenium levels instrumental neutron activation analysis via ⁷⁵Se was used. After labeling of rats in vivo with ⁷⁵Se-selenite and separation of the proteins in the renal homogenate and cell compartments by electrophoretic methods, the ⁷⁵Se-containing proteins were detected by autoradiography. In this way, six selenium-containing proteins with molecular masses of 15, 16, 20, 23-25, 40-42 and 58-60 were found in the endoplasmatic reticulum. All of those were characterized as selenocysteine-containing selenoproteins. This revised version was published online in August 2006 with corrections to the Cover Date.