Enzyme-catalyzed gel proteolysis: an anomalous diffusion-controlled mechanism.

Enzyme-catalyzed proteolysis of gelatin gels has been studied. We report a gel degradation rate varying as the square of the enzyme concentration. The diffusion motion of enzymes in the gel has been measured by two-photon fluorescence correlation spectroscopy and identified as being anomalously slow.

The nitrogen source-dependent 126-kDa protein from Synechococcus PCC 7942 plasmalemma: a trimer of the NrtA nitrate-binding protein.

Expression of a 126-kDa protein in the plasmalemma (cytoplasmic membrane) from Synechococcus PCC 7942 is dependent on the nitrogen source. Polyclonal antibody raised against the NrtA protein reacted with the 126-kDa protein. Two peptide sequences from the 126-kDa protein were retrieved in NrtA.

Determination of inorganic phosphate by coupling thymidine phosphorylase and reversed-phase high-performance liquid chromatography: application to tonoplast pyrophosphatase activity.

We developed an HPLC method for the measurement of inorganic phosphate using thymidine phosphorylase (EC 2.4.2.

Nitrogen source-dependent expression of a 126 kDa protein in the plasma membrane of the cyanobacterium Synechococcus PCC 7942.

The expression of a 126 kDa protein in the cytoplasmic membrane of Synechococcus PCC 7942 is shown to be dependent on the nitrogen source. It is absent in ammonium-grown cells and its quantity is inversely related to the concentration of nitrate or nitrite in the growth medium. Addition of ammonium-grown cells to a medium containing nitrate or L-methionine-DL-sulfoximine results in the expression of this protein.

Studies on the surface properties of human lymphocytes by photon correlation spectroscopy technique.

Electrokinetic behaviour of human lymphocytes was studied by photon correlation spectroscopy technique on laser IR-spectrometer. The electrophoretic mobilities (EPMs) were measured for peripheral blood lymphocytes (PBL) and CEM-C12 T cell line in 1:1 electrolyte at 22 degrees C. Plots of mobility vs ionic strength in the range 0.