Escherichia coli accumulates thiomethyl-beta-d-galactoside against a concentration gradient under anaerobic conditions. The accumulation was abolished by carbonylcyanide m-chlorophenylhydrazone, tetrachlorosalicylanilide, 2,4 dinitrophenol, and other uncouplers of oxidative phosphorylation even though oxidative phosphorylation would not be expected to occur anaerobically. In the presence of the...

OBJECTIVES The essential oil of Melaleuca alternifolia (tea tree oil) and its components have antimicrobial activity against a wide range of Gram-positive and Gram-negative bacteria, fungi and viruses. The mechanism(s) by which Pseudomonas aeruginosa NCTC 10662 maintains a decreased susceptibility to tea tree oil and components was investigated. RESULTS Ethylene diamine tetraacetic acid enhan...

Abscisic acid (ABA) uptake by Amaranthus tricolor cell suspensions was found to include both a nonsaturable component and a saturable part with K(m) of 3.74 +/- 0.43 micromolar and an apparent V(max) of 1.5 +/- 0.12 nanomoles per gram per minute. These kinetic parameters as well as the uptake by intact cells at 0 degrees C or by frozen and thawed cells, are consistent with operation of a satura...

Photoformation of metalloporphyrin cations in a lipid bilayer increases the ionic currents of negative and decreases those of positive hydrophobic ions. At low concentrations of the mobile hydrophobic ion, a 30% change in conductivity is observed that decreases with increasing concentration of positive tetraphenylphosphonium ion and increases drastically with increasing concentration of negativ...

A technique has been developed for the rapid and simple measurement of ribulose 1,5-bisphosphate from isolated spinach chloroplasts. The endogenous ribulose bisphosphate was detected enzymically using (14)CO(2) and ribulose bisphosphate carboxylase/oxygenase released from the chloroplasts. Ribulose 5-phosphate kinase was inhibited with 0.4 to 0.6 millimolar 2,6-dichlorophenol-indophenol and 4 m...

Localization and staining features of the oxidant-sensitive fluorescent probe 2'7'-dichlorofluorescin (DCFH) were evaluated in isolated cardiac muscle cells. Cardiomyocytes rapidly accumulated the probe and retained steady levels of DCFH and its highly fluorescent oxidized product dichlorofluorescein (DCF) in probe-free medium for 1.5 h. DCF was associated with mitochondria and was released by ...

The regulation of polyamine transport by antizyme, a protein that is involved in the rapid degradation of ornithine decarboxylase (ODC), was studied in FM3A mouse cells overproducing ODC. Both artificial (Z1) and natural antizymes not only inhibited polyamine uptake but also stimulated polyamine excretion. The properties of the polyamine transporter regulated by antizyme were characterized. The...

Digestion of spinach chloroplasts with pancreatic lipase or trypsin effectively uncoupled electron transport. Continued digestion led to inhibition of saturated rates of Hill reaction activity and a decrease in quantum yield. Irradiation with ultraviolet light decreased the quantum yield and inhibited Hill activity, but did not uncouple. Ascorbate-dichlorophenol-indophenol-mediated reduction of...

Cytoplasmically synthesized precursors of mitochondrial polypeptides have previously been observed in trace amounts after pulse labeling of yeast spheroplasts or after in vitro translation of yeast mRNA (Maccecchini, M. L., Rudin, Y., Blobel, G., and Schatz, G. (1979) Proc. Natl. Acad. Sci. U. S. A. 76, 343-347). Some of these precursors are shown here to accumulate in large amounts (up to 150 ...