A General Assay Method for Nucleotide Pyrophosphorylases

A luminescence-based assay of UDP-sugar producing pyrophosphorylases†

A possible role of purine nucleotide pyrophosphorylases in the regulation of purine uptake by Bacillus subtilis.

The uptake of radioactive purines in resting cell suspensions of Bacillus subtilis has been studied. Initial rates of uptake obeyed saturation kinetics (e.g. apparent Km adenine, 0.6 PM). Subsequent uptake proceeded in steplike increments. Further studies were aimed at delineating the control mechanism for this uptake. Purines were highly concentrated with respect to the medium, but the intrace...

A Validated HPTLC-Densitometric Method for Assay of Aucubin in Vitex agnus-castus L.

Vitex agnus-castus L. is a medicinal plant which is used in several dosage forms for women hormonal disorders and standardized according to the iridoids or flavonoids content. Aucubin, an iridoid glycoside, considered as a marker in some formulations. In this research, a thin layer chromatographic method with densitometric detection has been developed for quantitative determination of aucubin i...

A Validated HPTLC-Densitometric Method for Assay of Aucubin in Vitex agnus-castus L.

Vitex agnus-castus L. is a medicinal plant which is used in several dosage forms for women hormonal disorders and standardized according to the iridoids or flavonoids content. Aucubin, an iridoid glycoside, considered as a marker in some formulations. In this research, a thin layer chromatographic method with densitometric detection has been developed for quantitative determination of aucubin i...

A sensitive cyclic nucleotide phosphodiesterase assay for transient enzyme kinetics.

A new assay for cyclic nucleotide phosphodiesterase has been developed by using reverse-phase column chromatography for the separation of product and substrate of the enzymatic reaction. The polar 5'-nucleotides are not retarded by the column, while the more lipophilic cyclic nucleotides bind to the column. Properties such as pH and ionic strength of the incubation mixture or the elution buffer...