Characterization and purification of a membrane-bound archaebacterial pyrophosphatase from Sulfolobus acidocaldarius.
Plasma membranes of the thermoacidophilic archaebacterium Sulfolobus acidocaldarius (DSM 639) display a pyrophosphate-hydrolyzing activity [M. Lübben & G. Schäfer (1987) Eur. J. Biochem. 164, 533-540]. In our present work, we solubilized and purified this pyrophosphatase to homogeneity. It consists of a single subunit with a molecular mass of 17-18 kDa, forming an oligomer of 70 kDa under native conditions. Edman degradation revealed 30 amino acids of the N-terminus. The enzyme cleaves phosphoric-acid-anhydride bonds independently of monovalent or divalent cations. Temperature and pH optima of 75 degrees C and 3.5-3.7, respectively, characterize it as an ectoenzyme. Membrane lipids of Sulfolobus stimulate the activity. The dolichol-pyrophosphate-complexing peptide-antibiotic bacitracin inhibited growth of Sulfolobus. A possible function of the acid pyrophosphatase is the hydrolysis of dolichol pyrophosphate in connection with glycosylation reactions of membrane proteins.
Meyer
W
W
Institut für Biochemie, Medizinische Universität zu Lübeck, Federal Republic of Germany.
Schäfer
G
G
D000595:Amino Acid Sequence; D001414:Bacitracin / Q000494:pharmacology; D002384:Catalysis; D002462:Cell Membrane / Q000201:enzymology; D004789:Enzyme Activation; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000494:pharmacology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011499:Protein Processing, Post-Translational; D011755:Pyrophosphatases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D016944:Sulfolobus / Q000201:enzymology*; D013696:Temperature
D008055:Lipids; D001414:Bacitracin; D011755:Pyrophosphatases