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Biomedical subjects

J Mauck

Publications and source records attributed to J Mauck.

9 recordsLinked to original sources

Rapid purification of dipeptidyl peptidase IV from rat liver plasma membrane.

Dipeptidyl peptidase IV (EC 3.4.14.5) was solubilized from rat liver plasma membranes with sulphobetaine 14 and purified by successive affinity chromatography on Con A-Sepharose, wheat germ lectin-Sepharose and arginine-Sepharose columns. The specific activity of the final preparation was 49.4 mumol Gly-Pro p-nitroanilide/min per mg protein, representing a 1098-fold purification of the homogenate. SDS-polyacrylamide gel electrophoresis of the arginine-Sepharose eluate showed a single protein band with a molecular weight of 105,000. The isoelectric point was determined to be 3.9 under non-denaturing conditions with sulphobetaine 14. The preparation was free of post-proline cleaving enzyme. The content of aminopeptidase M was 0.2% of the total protein.

Animals

Half-lives of L-[35S]methionine and L-[3H]fucose of transferrin in the serum of rats.

The half-lives of 35S-labelled L-methionine and of 3H-labelled L-fucose of serum transferrin of rats were measured in pulse-chase experiments in vivo. Both L-[35S]methionine and L-[6-3H]fucose disappeared from transferrin with nearly the same half-lives of 33.8 h and 36.5 h, respectively. The data show that in this major serum glycoprotein peripheral carbohydrates and the protein moiety are degraded as a unit.

Animals

An acceptor-dependent polyglycerolphosphate polymerase.

A method for the extraction of polyglycerolphosphate polymerase from Bacillus subtilis membranes is described. Further purification by ion-exchange chromatography yields an enzyme fraction totally dependent on the addition of a heat-stable factor for activity. This factor was isolated from cell membranes and acts as an acceptor of glycerolphosphate units. The acceptor contains glycerolphosphate, glucosamine, and fatty acids, but its precise chemical structure has not yet been elucidated.

Bacillus subtilis

Mode of cell wall growth of Bacillus megaterium.

The growth of the cell wall of Bacillus megaterium KM was examined by labeling the cell wall uniformly with (3)H-alpha, epsilon-diaminopimelic acid and examining by radioautography the distribution of labeled cell wall material in daughter cells. The results indicate that the label is distributed uniformly to all daughter cells and rule out a single growth point, either central or apical, for these cells. The results strongly suggest that cell wall growth occurs by uniform deposition of new wall over the whole cell surface.

Autoradiography