Ornithine decarboxylase (EC 4.1.1.17) has been purified 3,500-fold from the plasmodia of Physarum polycephalum. The purified material exhibited a Km for ornithine of 0.6 mM and Vmax of 20 mumol of CO2 formed per min/mg at 30 degrees C (62 mumol/min/mg at 37 degrees C). It migrated as a single protein and activity species on high pressure liquid chromatography (TSK-3000) in 0.15 M NaCl (Mr = 80,...

We have examined the insulin-dependent phosphorylation of the insulin receptor in the isolated plasma membranes of 3T3-F442A adipocytes. Phosphorylation of the insulin receptor is detected readily in the plasma membrane of these cells by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In the presence of sodium dodecyl sulfate and under nonreducing conditions, the pred...

An estrogen-responsive murine Leydig cell tumor (M5480A) was examined for the presence of cross-reactive proteins to a monoclonal antibody directed against a Mr 24,000 estrogen-regulated protein in human breast cancer cells. Human breast tumor biopsies were used as controls for the cytosol preparations, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and Western blot conditions used ...

Rabbit testis contains a single molecular form of proacrosin which could be extracted at acid pH and purified 145-fold by Sephadex G-100, SE-Sephadex, and concanavalin A-Sepharose affinity column chromatography. The purified proacrosin was judged to be homogeneous on the basis of chromatographic analyses, disc and sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis, and immunodiffusi...

The proteins of [35S]methionine-labeled membranes of six human lymphoid cell lines were examined by electrophoresis in sodium dodecyl sulfate-polyacrylamide gradient slab gels in order to identify molecular differences among these tumors. The lymphoid cells were internally labeled with [35S]methionine, their membranes were isolated, and the reduced and alkylated membrane proteins were treated e...

Clostridium botulinum type F toxin of proteolytic Langeland strain was purified. Toxin in whole cultures was precipitated with (NH4)2SO4. Extract of the precipitate was successively chromatographed on diethylaminoethyl-cellulose at pH 6,0, O-(carboxymethyl) cellulose at pH 4.9, and finally diethylaminoethyl-cellulose at pH 8.1. The procedure recovered 14 percent of the toxin assayed in the star...

A bifunctional enzyme, consisting of 3-deoxy-n-arabinoheptulosonate 7-phosphate synthetase and chorismate mutase, has been purified to homogeneity from Bacillus subtilis. Ultracentrifugation revealed a single symmetrical peak of protein. A single protein band also was observed when the homogeneous preparation was subjected to polyacrylamide gel electrophoresis in the presence of sodium dodecyl ...

Chymotrypsin cleaves bacteriorhodopsin to two fragments: C-1, amino acids 72-248, and C-2, amino acids 1-71. Denaturation and renaturation of these fragments have been studied. Following denaturation in sodium dodecyl sulfate, both C-1 and C-2 regain secondary structure in phospholipid/cholate/sodium dodecyl sulfate mixed micelles. When combined, they form a complex with a secondary structure r...

A phospholipase A1 bound tightly to the membranes of Mycobacterium phlei cells was purified approximately 500fold to near homogeneity by extraction with Triton X-100, delipidation with organic solvents, solubilization with sodium dodecyl sulfate, column chromatographies on Sephadex G-200 in the presence of sodium dodecyl sulfate and on DEAE-cellulose in the presence of BRIJ 58, and sodium dodec...

The effect of detergents on the stability of enteric viruses was found to be highly dependent on pH. This was demonstrated primarily with two ionic detergents, sodium dodecyl sulfate (an anionic detergent) and dodecyltrimethylammonium chloride (a cationic detergent). Both detergents were shown to be potent virucidal agents for reovirus, but the effects of sodium dodecyl sulfate were minimal nea...