A rationally designed oligopeptide shows significant conformational changes upon binding to sulphate ions.

Oligopeptides that interact with oxoanions were developed by rational design methods. The substrate-binding site of the enzyme purine nucleoside phosphorylase served as a model for the design of the ionophores. The amino acids involved in the complexation of oxoanions were linked through flexible spacer residues.

Long-term excessive magnesium supplementation is deleterious whereas suboptimal supply is beneficial for bones in rats.

The long-term effects of a suboptimal magnesium supply inducing a marginal or moderate deficiency or of an excessive magnesium supplementation corresponding to a basal diet with a high pharmacological intake were investigated in 36 growing Sprague-Dawley female rats. The rats were randomly divided in three groups and received a purified diet with 7 g calcium, 5 g phosphorus and either 0.2, 0.

[Free intracellular magnesium in myocardium--measurement and physiological role--state of the art].

Magnesium is an important intracellular cation which is known to participate in over 300 biochemical reactions of the cell. Most of the cell's Mg2+ is bound to intracellular structures, and only 5% of the total Mg2+ are unbound and thus biologically active. Clinical data concerning the therapeutic value of Mg2+ in various conditions like myocardial infarction are conflicting, experimental support for a specific therapy is still lacking, because values of free intracellular myocardial Mg2+ as well as behaviour of (Mg2+)i during ischemia or changes of extracellular ion-concentrations have not been elucidated as yet.

Using N-aminoperylene-3,4:9,10-tetracarboxylbisimide as a fluorogenic reactand in the optical sensing of aqueous propionaldehyde.

Aldehydes are usually determined via chemical derivatization using a chromogenic and fluorogenic reagent followed by chromatographic separation and UV-visible detection. As a consequence, continuous on-line monitoring is impossible. Following our concept of reversible chemical reactions as the basis of optical sensors, we have investigated N-amino-N'-(1-hexylheptyl)perylene-3,4:9,10-tetracarboxylbisimide for aldehyde sensing.

Calibration of Mg(2+)-selective macroelectrodes down to 1 mumol l-1 in intracellular and Ca(2+)-containing extracellular solutions.

Using Mg(2+)-selective macroelectrodes based on the neutral carriers ETH 7025 and ETH 5506, methods were developed to determine accurately the apparent binding constant (Kapp) and purity, and hence the ionized magnesium concentration ([Mg2+]), in Ca(2+)-free, Mg2+ buffer solutions manufactured with either CDTA (trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid monohydrate) or EDTA. In nominally Ca(2+)-free solutions, calibration of the macroelectrodes was possible down to 1 mumol l-1 in both intracellular (ETH 7025)- and extracellular (ETH 5506)-like physiological solutions. The measured [Mg2+] in the buffer solutions overlapped with the [Mg2+] set by dilution alone, suggesting that the method was reliable.