We have isolated from Streptococcus faecalis plasma membranes a new protein, termed nectin, which is required for the attachment of the membrane enzyme, ATPase. Both nectin and membrane-bound ATPase are released from the native membranes by a procedure, described previously, which depends on repeated washing in dilute buffer without Mg++. Resolution of the solubilized nectin and ATPase can then...

[D-Ala2,Leu5]Enkephalin was readily metabolized by membranes (40,000 g pellet) prepared from heads of the housefly, Musca domestica, with Gly3-Phe4 being the major site of cleavage. This hydrolysis was only partially inhibited (40%) by 10 microM phosphoramidon, an inhibitor of endopeptidase-24.11, but was almost totally abolished in the presence of a mixture of 10 microM phosphoramidon and 10 m...

Lipid rafts have been identified in the membranes of mammalian cells, the yeast Saccharomyces cerevisiae, and the pathogenic fungus Candida albicans. Formed by a lateral association of sphingolipids and sterols, rafts concentrate proteins carrying a glycosylphosphatidylinositol (GPI) anchor. We report the isolation of membranes with the characteristics of rafts from the fungal pathogen Cryptoco...

Plasma membranes have been prepared from purified pachytene spermatocytes, round spermatids and residual bodies of the adult mouse testis using procedures modified from other authors'. Isolated membranes have been examined using electron microscopy, lectin binding and enzymic assays. Ultrastructural observation reveals smooth unit-membrane vesicles from 0.4-1.7 micrometer diameter. No contamina...

Plant protoporphyrinogen oxidase is of particular interest since it is the last enzyme of the common branch for chlorophyll and heme biosynthetic pathways. In addition, it is the target enzyme for diphenyl ether-type herbicides, such as acifluorfen. Two distinct methods were used to investigate the localization of this enzyme within Percoll-purified spinach chloroplasts. We first assayed the en...

This paper describes a light-addressed electrolytic system used to perform an electrodeposition of enzyme-entrapped chitosan membranes for multiplexed enzyme-based bioassays using a digital micromirror device (DMD). In this system, a patterned light illumination is projected onto a photoconductive substrate serving as a photo-cathode to electrolytically produce hydroxide ions, which leads to an...

With intact spinach (Spinacia oleracea L. cv. Vital R) chloroplasts, the activity of the NADP-dependent malate dehydrogenase after activation by light was 30 micromoles of malate formed per milligram of chlorophyll per hour; an identical rate of O(2) evolution was obtained upon oxaloacetate reduction by the intact plastids. However, when the activity of NADP-dependent malate dehydrogenase was m...

Chlorophyll (Chl) is essential for photosynthesis and needs to be produced throughout the whole plant life, especially under changing light intensity stress conditions which may result in destruction elimination of these pigments. All steps Mg-branch tetrapyrrole biosynthesis leading Chl formation are carried out by enzymes associated with plastid membranes. Still significance protein-membrane ...

The relationship between adenylate cyclase activity in the synaptic membrane fraction (M1) of rat brain and lipid peroxidation of these membranes was examined. In the presence of 5 mM dithiothreitol (DTT), 1 to 10 microM Fe/+ activated adenylate cyclase 2- to 4-fold. Of several metal ions, Fe2+ was the most effective. Other enzymes in M1, such as Mg2+-ATPase, (Na+-K+)-ATPase, 5'-nucleotidase, a...