A simple and rapid method for the determination of phosphatase activities of living yeast cells is described. The method uses 2,4-dinitrophenol to stop enzyme synthesis without interfering with the subsequent enzyme determination.

Oxalate decarboxylase, a bicupin enzyme coordinating two essential manganese ions per subunit, catalyzes the decomposition of oxalate into carbon dioxide and formate in the presence of oxygen. Current efforts to elucidate its catalytic mechanism are focused on EPR studies of the Mn. We report on...

Retrograde axonal transport and fluorescent retrograde labelling of neurons were investigated in a crustacean motor system. A fluorescent tracer (Granular blue) was injected into an antennal muscle of rock lobster in order to identify the motor neurons innervating it. After an appropriate post-i...

This paper examined the preparation and characterization of lanthanum-doped phosphate glasses nanoparticles designed for effective management of bone regeneration and associated infections. Glasses incorporated different La2O3 contents (0, 5 and 10 mol%) were prepared successfully by a modified ...

This report demonstrates that the commonly used buffering agent Tris(hydroxymethyl)aminomethane (Tris) in concentrations of 5 and 30 mM inhibits calcium (Ca2+) uptake in both rat aortic and portal venous smooth muscle. The data indicates that total exchangeable Ca2+ in portal vein is reduced by ...

In this study, new hydrogels in rod shape were prepared from N-isopropyl acrylamide (NIPA), N-acryloyl-tris-(hydroxymethyl) aminomethane (NAT) and N,N′-methylenebisacrylamide (BIS). The effect of the incorporation of NAT into poly(N-isopropyl acrylamide) (PNIPA) structures for which the monomer...

Radiation sensitive indicators based on dyed polyvinyl alcohol (PVA) containing acid- sensitive dye (tetrabromophenol blue, TBPB) and chloral hydrate (CCl3·CH·(OH)2, 2,2,2-trichloroethane-1,1-diol) have been developed. These plastic film dosimeters undergo color change from blue (the alkaline ...

After acid decomposition and potassium pyrosulfate fusion, niobium (1—26 ppm) is separated from interfering elements by extraction into methyl isobutyl ketone from 6 M H2SO4—2 M HF and back-extracted into water. The niobium—sulfochloro-phenol S complex is extracted into amyl alcohol.

The prs gene encoding phosphoribosyl diphosphate (PRPP) synthase of the hyperthermophilic autotrophic methanogenic archaeon Methanocaldococcus jannaschii has been cloned and expressed in Escherichia coli. Subsequently, M. jannaschii PRPP synthase has been purified, characterised, crystallised, a...

Publisher SummaryThis chapter describes the best methods available for regeneration of adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and adenosine monophosphate (AMP) and details several applications of these methods in enzyme-catalyzed syntheses. In particular, it give procedure...

In aqueous biological environment DNA is typically deprotonated. The metastable deprotonated DNA nucleobases are important reaction intermediates in low-energy electron induced damage to DNA. By comparing the metastable decay of small deprotonated DNA building blocks (thymine, thymidine, d-ribos...

Nucleosides and their analogues play a crucial role in the treatment of several diseases including cancers and viral infections. Their therapeutic efficiency depends on their capacity to be converted to the active nucleoside triphosphates form through successive phosphorylation steps catalyzed b...

Primary and secondary metabolite profiles were analyzed in roots and leaves of the halophytic shrub Prosopis strombulifera in response to control plants (no salt added in the growing media) and to lowering the osmotic potential to −1.0, −1.9, and −2.6 MPa generated by NaCl, Na2SO4, and the iso-o...

Thymidine kinase 1 (TK1) is an enzyme involved in DNA synthesis whose activity in serum is indicative of tumor proliferation and the severity of blood malignancies. 3′-deoxy-3′-fluorothymidine (FLT), a specific exogenous substrate for TK1, is phosphorylated by TK1 in the presence of a phosphor...

Polymerization of amino-acid acyl cyclic-3′,5′-nucleotides is postulated to be the origin of RNA and associated protein in prebiotic molecular evolution. The enthalpy change in the intramolecular interaction between the nucleotide base and the amino-acid side chain determines the stability of ...

The preparation of 2′-O-tetrahydropyranyl-uridine and -adenosine is described. Both diastereoisomers of each derivative have been isolated in a pure crystalline state. The high-melting (more laevorotatory) diastereoisomer derived form each nucleoside has been converted to its 5′-O-pivaloyl der...

Two complexes of bovine seminal ribonuclease with dinucleotides, uridylyl(2′-5′)adenosine (UpA) and 2′-deoxycytidylyl(3′-5′)-2′-deoxyadenosine (d(CpA)), were crystallized under unusual conditions involving a liquid-liquid phase separation. This phenomenon was induced by adding small aliquo...

Agar dilution susceptibility testing of temafloxacin, cefotetan, clindamycin, and ciprofloxacin was performed in 103 genital tract isolates of Bacteroides. The respective minimum inhibitory concentration inhibiting 90% of the strains tested were temafloxacin, 4 μg/ml; cefotetan, 256 μg/ml; cli...

Temafloxacin is a new antibacterial agent of the fluoroquinolone group. In comparison with ciprofloxacin, the current leading quinolone, temafloxacin shows higher and longer lasting plasma concentrations after equivalent doses due to an almost complete gastrointestinal absorption and a lower tot...

A series of sterically hindered o-(branched alkoxy)-tert-butoxybenzenes was efficiently prepared in good yields owing to a new practical and simple preparation of o-tert-butoxyphenol starting from catechol and isobutene. Use of DMF di-tert-butyl acetal reagent instead of isobutene/H2SO4 (cat.) f...