Kinetics of L-gamma-Glu-pNA hydrolysis by destabilase, the enzyme from the medicinal leech Hirudo medicinalis

The molecular mass of destabilase isolated from the medicinae leech Hirudo medicinalis was found to be equal to 12.3 kDa. A kinetic analysis of the sole presently known synthetic substrate, L-gamma-Glu-pNA, showed that the enzyme is relatively stable to heating (5 min, 70 degrees C); the pH optimum lies at 7.0-8.5. The enzyme has a specific activity of 0.15 x 10(-9) mol.s-1.mg-1; Km = 2.2 x 10(-4) M, kcat is 3.53 x 10(-3) s-1 (pH 8.0, 37 degrees C).     

Length polymorphism of the B2-VNTR minisatellite repeat of the bradykinin B2 receptor gene in healthy Russians and patients with coronary heart disease

Bradykinin B2 receptor is involved in many processes, including the regulation of blood pressure and smooth muscle contraction, vasodilation, inflammation, edema, cell proliferation, and pain. This receptor attracts special attention as one of the factors that have cardioprotective and infarct-limiting effects. Certain genetic variants of the coding and noncoding regions of the bradykinin B2 receptor gene (BDKRB2) may play a role in modulating its expression. The 3′-untranslated region of BDKRB2 exon 3 harbors a minisatellite repeat (B2-VNTR), which affects the mRNA stability. Hence, it is of interest to study a possible association of B2-VNRT alleles with various forms of coronary heart disease (CHD). In our work the allele and genotype frequency distributions of B2-VNTR were compared between healthy individuals and patients with CHD (angina pectoris or myocardial infarction (MI)) of the Russian ethnic group. Based on its length polymorphism, B2-VNTR was classed with low-polymorphic non-hypervariable minisatellites. Three B2-VNTR alleles, which consisted of 43, 38, and 33 repeats, were observed in all investigated cohorts. The alleles with 43 and 33 repeats were the most prevalent. The allele and genotype frequencies of B2-VNTR did not significantly differ between males and females in control group, and also between healthy males and males with angina pectoris or MI. Thus, B2-VNTR length polymorphism was not associated with these clinical forms of CHD in males. However, we do not exclude the possibility of an association of the short B2-VNTR alleles (38 and 33 repeats) with a cardioprotective effect in females with CHD. This hypothesis requires further investigation.     

Interaction of native Bowman—Birk soybean protease inhibitor and its hydrophobized derivative with multilamellar vesicles of soybean phospholipids

The interaction of native Bowman-Birk soybean protease inhibitor (BBI) and its hydrophobized derivative with multilamellar vesicles of various soybean phospholipids was investigated. Decrease in pH and introduction of negatively charged components to the lipid mixture increased BBI content in the protein-lipid complex. This suggests a contribution of electrostatic forces in the protein-lipid interaction. Protein hydrophobization insignificantly influenced BBI binding to lipids. In the complex with lipids, both proteins (BBI and its hydrophobized derivative) retained high anti-chymotrypsin activity (75-100%), which was not influenced by the presence of the ionic detergent sodium deoxycholate.     

Regulation of Apolipoprotein A-I Gene Expression in Human Macrophages by Oxidized Low-Density Lipoprotein

Biochemistry (Moscow) - Apolipoprotein A-I (ApoA-I) is a key component of reverse cholesterol transport in humans. In the previous studies, we demonstrated expression of the apoA-I gene in human...     

Genetic diversity and differentiation of populations of scots pine in Southern Siberia and Mongolia

This paper presents the results of studying the genetic diversity, structure, and degree of differentiation of island populations of Scots pine (Pinus sylvestris L.) growing in Southern Siberia (south of Krasnoyarsk krai, Khakassia, Tuva, and Buryatia) in the northeastern part of Mongolia, which were obtained on the basis of an analysis of 20 isoenzymic loci.     

Genetic Variability in Scotch Pine in the Southeastern Part of Its Range

The main parameters of genetic variability have been determined in an isolated natural Scotch pine population from Chita oblast (Tsasuchei Forest) by analysis of 19 genes coding for nine enzymes: GDH, IDH, LAP, PGM, AAT, ADH, MDH, 6-PGD, and DIA. Polymorphic genes constituted 63.2% of all structural genes studied in the population at the 99% polymorphism criterion. The mean number of alleles per locus was 1.63. The observed and expected heterozygosities were 0.237 and 0.251, respectively. These estimates are close to the corresponding mean values for Scotch pine according to the data on 18 or more structural genes.     

Computer simulation of a cerebellar cortex compartment

Computer simulation experiments are described regarding information storage and retrieval at a network consisting of one Purkinje cell and 20,000 granule cells. The information content depends on a scheme type and the properties of Purkinje cells. It is shown that a practically attainable information record efficiency is of the order 0.6 bit per binary memorising synapse. Associative information recall is demonstrated for the Marr's memory unit and expressions are derived for an information-content estimation based on parameter values obtained by simulation. The consequences of this computer simulation for physiological experiments are extensively discussed.