[Determination of melatonin in biological fluids].

The review considers main approaches to solving the problem in the quantification of melatonin and describes physicochemical and biological methods for melatonin determination in biological fluids (saliva, urine, plasma) and tissues. The impetus to writing this paper came from the considerably growing interest of the scientific community in melatonin and the in-depth studies of its physiological role, which had revealed a diversity of its previously unknown most important functions and confirmed its presence in many compartments of the body. Due to the specificity of its molecular structure and low concentration, melatonin remains invisible for many conventional analyses.

[Point contacts of T7 RNA polymerase in the promotor complex, as determined with phosphate-activated oligonucleotide derivatives].

The contacts between phosphate groups of promoter DNA an Lys or His of T7 RNA polmerase (Pol) in the Pol-promoter complex were studied with single- and double- stranded oligonucleotides, which corresponded to the T7 promoter consensus and contained activated phosphate groups at position +1, +2, or -14 relative to the transcription start. To obtain reactive groups, terminal phosphates were modified with N-oxybenzotriazole (HOBT), and internucleotide phosphates were repalced with a trisubstituted pyrophosphate (TSP). The resulting derivatives produced covalent complexes with T7 Pol.