Mitochondrial dolichyl‐phosphate mannose synthase

Abstract

Mitochondrial dolichyl‐phosphate mannose synthase has been purified to homogeneity using an original procedure, reconstitution into specific phospholipid vesicles and sedimentation on a sucrose gradient as final step. The enzyme has an apparent molecular mass of 30 kDa on an SDS/polyacrylamide gel. Increased enzyme activity could be correlated with this polypeptide band. A specific antibody was raised in rabbits against this transferase. Specific IgG obtained from the immune serum removed enzymatic activity from a detergent extract of mitochondrial outer membrane and reacted specifically with the 30‐kDa band on immunoblots. Furthermore, an immunocytochemical experiment proved the localization of dolichyl‐phosphate mannose synthase on the cytosolic face of the outer membrane of mitochondria.