Bacillus subtilis possesses a secondary transporter CitM that is specific for the complex of citrate and Mg but is also capable of transporting citrate in complex with the heavy metal ions Zn, Ni and Co. We report on the impact of CitM activity on the toxicity of the heavy metals Zn, Ni and Co + in B. subtilis. In a CitM deletion mutant or under conditions when CitM is not expressed, the toxic ...

Fructose 1,6-bisphosphate aldolase (FBA) is important for both glycolysis and gluconeogenesis in life. Class II (zinc dependent) FBA is an attractive target for the development of antibiotics against protozoa, bacteria, and fungi, and is also widely used to produce various high-value stereoisomers in the chemical and pharmaceutical industry. In this study, the crystal structures of class II Esc...

Adenosine nucleosidase (adenosine ribohydrolase, EC 3.2.2.7) which catalyzes the deribosylation of N(6)-(Delta(2)-isopentenyl)adenosine and adenosine to form the corresponding bases was partially purified from wheat germ. This enzyme (molecular weight 59,000 +/- 3,000) deribosylates the ribonucleosides at an optimum pH of 4.7 K(m) values for the cytokinin nucleoside and adenosine are 2.38 and 1...

The purpose of this study was to determine the effect of the covalent incorporation of hyaluronic acid (HA) into conventional hydrogel and hydrogels containing silicone as models for contact lens materials on the uptake and release of the fluoroquinolone antibiotic ciprofloxacin and the anti-inflammatory steroid dexamethasone phosphate. A 3 mg/mL ciprofloxacin solution (0.3% w/v) and a 1 mg/mL ...

As the nature of the causative agent of yellow fever was unknown, it was necessary at the beginning of these experiments to formulate a spedal method of cultivation. The methods employed have been similar to those recommended 1 for the cultivation of Leptospira icterohcemorrhagice (Inada and Ido). Instead of the serum and citrate plasma of the rabbit or other animal, serum and plasma from nonim...

When cultured in a defined citrate medium supplemented with 1 mM gallium (III) Pseudomonas fluorescens ATCC 13525 experienced a lag phase of 40 h with no apparent diminution in cellular yield. Following initial uptake of the metal-ligand complex, gallium was secreted in the spent fluid. This lag phase was abolished either by inoculating the medium with gallium adapted cells or by inclusion of i...

The objective of this study was to test the effect of increasing fatty acid concentrations on substrate fluxes through pathways leading to citrate synthesis and release in the heart. This was accomplished using semirecirculating work-performing rat hearts perfused with substrate mixtures mimicking the in situ milieu (5.5 mM glucose, 8 nM insulin, 1 mM lactate, 0.2 mM pyruvate, and 0.4 mM oleate...

The influences of the pH, tripolyphosphate (TPP) concentration, and ionic strength of the gelling medium on the entrapment efficiency, release, and activity of lipase in chitosan hydrogel beads were studied. A solution of Candida rugosa lipase was prepared in a 1.5% w/v chitosan and 1% (v/v) acetic acid medium, and dropped into a TPP solution. Release of lipase in pH 7.2 Tris buffer was monitor...