In vitro synthesis of Escherichia coli manganese-containing superoxide dismutase, directed by the plasmid pDT1-5, has been achieved. The Mn superoxide dismutase polypeptide was identified by electrophoresis on polyacrylamide gels, immunoprecipitation, and the competitive immunoprecipitation effect of pure, active E. coli Mn superoxide dismutase. Dithiothreitol and glutathione, but not cysteine,...

Sed-P2ase, Ferredoxin, Thioredoxin, Enzyme Regulation 1. A substrate-specific sedoheptulose-l,7-bisphosphatase has been found in chloroplasts and separated from its fructose-1,6-bisphosphatase counterpart. Experiments with antibodies indicate that the two enzymes are structurally different. 2. Activity of the sedoheptulose-l,7-bisphosphatase enzyme was dependent on M gi+ and a reductant. The mo...

The present study demonstrates the existence of tissue transglutaminase in rabbit alveolar macrophages and measures the effects of cigarette smoke extracts on the activity of enzyme partially purified from these cells. The effects of smoke on transglutaminase purified from guinea pig liver are also measured. A water soluble component of gas-phase cigarette smoke inhibits both enzymes in a dose-...

The vitamin K-dependent carboxylating system has been solubilized by Lubrol PX or Triton X-100 treatment of vitamin K-deficient rat liver microsomes. As obtained from vitamin K-deficient rat liver, this soluble preparation is dependent upon the in vitro addition of vitamin K1 for carboxylating activity. The enzyme system is complex and is dependent upon NADH and dithiothreitol for maximum activ...

The extrusion apparatus of the microsporidian parasitic protozoan Nosema michaelis discharges an invasion (or polar) tube with a velocity suitalbe for piercing cells and injecting infective sporoplasm. The tube is composed of a polar tube protein (PTP) which consists of a single, low molecular weight polypeptide slightly smaller than chymotrypsinogen-A. Assembled PTP tubes resist dissociation i...

on either DEAE cellulose or Sephacryl S-200. About 80% of the reductase was one form in the chloroplast and the rest was a second form in the cytosol as determined by chromatography and by fractionation of subcellular organelles. The amount of activity detectable in the chloroplast fraction was 10.7 micromoles of dihydroxyacetone phosphate reductase per hour per milligram chlorophyll from spina...

Conformational movement of the C-terminal alpha7 helix in the integrin inserted (I) domain, a major ligand-binding domain that adopts an alpha/beta Rossmann fold, has been proposed to allosterically regulate ligand-binding activity. Disulfide bonds were engineered here to reversibly lock the position of the alpha7 helix in one of two alternative conformations seen in crystal structures, termed ...