The fraction in which direct contact occurs between micellar-phase phenanthrene and the bacterial cell surface was estimated by measuring the toxicity of nonionic surfactant (Tween 80 and Triton X-100) solutions to the phenanthrene-degrading bacterium, Pseudomonas putida P2. Cell viability of completely dissolved phenanthrene decreased by 30% at concentrations greater than 0.3 mg L(-1), which i...

Dictyostelium discoideum plasma membranes isolated by each of three procedures bind F-actin. The interactions between these membranes and actin are examined by a novel application of falling ball viscometry. Treating the membranes as multivalent actin-binding particles analogous to divalent actin-gelation factors, we observe large increases in viscosity (actin cross-linking) when membranes of d...

In the configuration of an electrode-separated piezoelectric sensor (ESPS), the quartz crystal surface is in a direct contact with the liquid phase. The quartz surface can be hydrated to form silanol groups, which can adsorb nonionic surfactant Triton X-100 through hydrogen-bonding interaction between the silanol OH group and the ether oxygen atoms. The adsorption process of Triton X-100 on qua...

Rat brain dipeptidyl aminopeptidases I to IV were assayed in the soluble and membrane-bound fractions of rat brain, and the effects of the detergents Triton X-100 and sodium deoxycholate on their activities were studied. Dipeptidyl aminopeptidases I and II were significantly inhibited in the presence of sodium deoxycholate, but were not affected by the presence of Triton X-100. However, dipepti...

The colicin A lysis protein, Cal, is synthesized at the same time as colicin A by Escherichiu coli harbouring plasmid pColA after induction by mitomycin C. Its function in the induced bacteria involves the release of colicin A, quasi-lysis, the death of the producing cells and the activation of the outer membrane phospholipase A. We have found that these various functions are affected different...

Phosphatidylserine decarboxylase activity has been characterized in membrane preparations from Clostridium butyricum ATCC 19398. A particulate fraction was shown to catalyze the formation of phosphatidylethanolamine and plasmenylethanolamine when vesicles containing phosphatidylserine and plasmenylserine were used as substrate. No plasmenylethanolamine was formed when phosphatidylserine alone w...

Fluorescent γ-cyclodextrin derivatives, modified using N-phenyl-x-anthracenecarboxamido (ACs; x = 9, 1), were synthesized and investigated using fluorescence and UV-vis spectroscopy. Fluorescence enhancements of ACs were observed up to 12-fold by the addition of sodium dodecyl sulfate (SDS) below the critical micellar concentration (CMC). In the presence of a nonionic surfactant, such as Trit...