The principal enzyme of human prostatic acid phosphatase [orthophosphoric monoester phosphohydrolase (acid optimum), EC 3.1.3.2], which had been highly purified by affinity chromatography, isoelectric focusing, and gel filtrations, was shown to be homogeneous at pH 5.0 by sedimentation equilibrium analysis. The amino acid composition was determined and the sedimentation coefficient of the nativ...

A proteolipid isolated from yeast mitochondrial adenosinetriphosphatase (subunit 9) (ATP phosphohydrolase; EC 3.6.1.3) by chloroform/methanol extraction has been shown to discharge photo-induced potentials across a planar phospholipid membrane containing bacteriorhodopsin. Oligomycin, a specific inhibitor of oxidative phosphorylation which binds to this protein, allows the potential gradient to...

Bacteriophage phi 6 contains three segments of double-stranded RNA. The procapsid consists of proteins P1, P2, P4, and P7, which are encoded by the viral L segment. cDNA copies of this segment have been cloned into plasmids that direct the production of these proteins, which assemble into polyhedral procapsids. These procapsids are capable of packaging plus-sense phi 6 RNA in the presence of nu...

A new procedure is described for extracting, purifying, and crystallizing alkaline phosphatase orthophosphoric monoester phosphohydrolase (EC 3.1.3.1) from human intestinal mucosa. Active enzyme, extracted with trichiorotrifluoroethane, is subsequently purified by chromatography on Sephadex G-200 and DEAE Sephadex. The acetone and ammonium sulfate precipitation steps that are part of the conven...

Preparations of the "induced protein" which appears in the rat uterus within 40 min of estradiol administration have recently been reported to contain phosphoprotein phosphatase (phosphoprotein phosphohydrolase, EC 3.1.3.16) activity. We found that these two proteins distribute differently on ammonium sulfate fractionation of uterine cytosol. Preparative cellulose acetate electrophoresis afford...

A technique is described for the radiochemical assay of phosphatidic acid phosphohydrolase activity in rat brain. Radiochemically pure 32P-labeled phosphatidic acid of known specific radioactivity and structure, which was biosynthesized in vitro by the diacylglycerol kinase of E. coli, was used as the substrate. As little as 5 microgram of microsomal or mitochondrial protein can be used for the...