[A new bromine-containing reagent for cysteine modification].

5-Bromo-2[(2-iodoacetyl)amino]benzenesulfonic acid (AIBSA), a reagent for modification of free of cysteine thiol groups in proteins and peptides, was synthesized. Rate constants of its interaction with thiol groups were determined. The presence of a bromine atom allows an easy identification of the AIBSA-labeled peptides in mass spectra due to the characteristic isotope distribution. The compound is stable in solution and under exposure to light.

[Efficiency of Siberian pine oil in complex treating of people ill with benign hypertension].

For people ill with benign hypertension and going through basis hypotensive therapy, taking in Siberian pine nut oil as much as 17,5 g per day, is accompanied by cholesterol-lessening effect, normalization of lipid spectrum of blood, systolic (maximum) benign pressure and lessening of surplus body mass.

[Isolation and characteristic of super long-chain unsaturated aldehydes from the freshwater sponge Lubomirskia baicalensis].

Several unusual overlong-chain unsaturated aldehydes (22:1, 22:2, 23:1, 24:1, 24:2, and 25:2) were found in total lipids of the endemic sponge Lubomirskia baicalensis from Baikal Lake. Tetracos-17-enal was identified as the major aldehyde of the mixture using GC-MS and 1H and 13C NMR spectroscopy. A procedure for the isolation of total overlong-chain aldehydes was suggested. We think that the overlong-chain aldehydes defend the sponge from fouling and predators. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2005, vol. 31, no. 6; see also http://www.maik.ru.

[Conservative motif CMLD in silicic acid transport proteins of diatom algae].

Sequencing of fragments of genes coding for silicic acid transport (SIT) proteins of diatoms of evolutionary distant classes (centric Chaetoceros muelleri Lemmermann, pennate araphid Synedra acus Kützing, pennate raphid Phaeodactylum tricornutum Bohlin, and pennate with keeled raphe system Cylindrotheca fusiformis Reimann et Lewin), revealed the presence in these proteins of a conservative amino acid motif CMLD. Hydropathy profiles suggest that CMLD occupies a position between two transmembrane strands which do not contain lysine and arginine residues. The two strands are good candidates for the role of the channel along which transport of silicic acid occurs. CMLD is a rare motif. Diatoms are known to need Zn2+ for the incorporation of silica. Presumably, CMLD is the site of Zn2+ binding of SITs. We found that the growth of diatoms is inhibited by a negatively charged alkylating reagent 5-(2-iodoacetamidoethyl)aminonaphtalene-1-sulfonic acid which cannot penetrate through the cell membrane. Cysteine of CMLD can be a target of this reagent. Synthetic peptide NCMLDY forms a complex with Zn2+, as revealed by the fact that the ion considerably reduces the rate of alkylation of the peptide.