Amplification of DNA sequences in Epstein-Barr virus and human immunodeficiency virus using DNA polymerase from Thermus thermophilus

Using thermophilic DNA-polymerase from Thermus thermophilus we have amplified by polymerase chain reaction (PCR) specific DNA sequences of Epstein-Barr virus (EBV) and human immunodeficiency virus (HIV). DNA-polymerase from Thermus thermophilus (the molecular mass of 80 to 86 kDa) differs in its physico-chemical properties from DNA-polymerase from the Thermus acquaticus (the molecular mass of 62 to 68 kDa). To amplify the specific EBV DNA sequence oligonucleotide primers for the virus replicon region (oriP-region) were used. As a result of amplification, a specific 405 b.p. DNA fragment was produced. Primers for the virus Gag region were used for amplification of HIV DNA. The possibility to conduct amplification cycles under two temperature conditions was demonstrated.     

Increase in Athletes’ Functional Capacities via Biological Feedback

The method of active self-regulation of functions on the basis of biological feedback via the electroencephalogram (EEG-BFB) was tested. A relatively short-term EEG-BFB exerts a strong beneficial effect on the functional state of various systems of organs and the human body as a whole.__________Translated from Fiziologiya Cheloveka, Vol. 31, No. 3, 2005, pp. 93–99.Original Russian Text Copyright © 2005 by Vysochin, Denisenko, Gordeev.     

A comparative study of the effectiveness of regulatory peptides in acute experimental pancreatitis

The effect of regulatory peptides on the functional activity of pancreatic cells and phagocytic cells of reticuloendothelial system were determined in intact dogs against the background of acute experimental pancreatitis. Assessment of the efficacy of regulatory peptides was made with the aid of scintigraphic studies in gamma chamber using for this purpose colloid 198Au and 75Se-methionine. It was established that introduction of regulatory peptides to dogs leads to inhibition of capture of labeled methionine by pancreatocytes, practically not influencing the elimination of colloid gold from circulation.     

Single Protein Molecule Mapping with Magnetic Atomic Force Microscopy

Understanding the structural organization and distribution of proteins in biological cells is of fundamental importance in biomedical research. The use of conventional fluorescent microscopy for this purpose is limited due to its relatively low spatial resolution compared to the size of a single protein molecule. Atomic force microscopy (AFM), on the other hand, allows one to achieve single-protein resolution by scanning the cell surface using a specialized ligand-coated AFM tip. However, because this method relies on short-range interactions, it is limited to the detection of binding sites that are directly accessible to the AFM tip. We developed a method based on magnetic (long-range) interactions and applied it to investigate the structural organization and distribution of endothelin receptors on the surface of smooth muscle cells. Endothelin receptors were labeled with 50-nm superparamagnetic microbeads and then imaged with magnetic AFM. Considering its high spatial resolution and ability to “see” magnetically labeled proteins at a distance of up to 150 nm, this approach may become an important tool for investigating the dynamics of individual proteins both on the cell membrane and in the submembrane space.     

Adaptation ofRhodococcus rhodochrous M8, a producer of acrylamide, to changes in ammonium concentration in the growth medium

The mechanism of adaptation of the acrylamide producing strainRhodococcus rhodochrous M8 to changes in ammonium concentrations in the medium was studied. An increase in the content of ammonium in the medium changed the activity of glutamine synthetase (GS) (EC 6.3.1.2) and glutamine dehydrogenase (GD) (EC 1.4.1.4), the enzymes of ammonium assimilation, as well as the activities of enzymes responsible for nitrile utilization: nitrile hydratase (EC 4.2.1.84) and amidase (EC 3.5.1.4). This also inhibited the activation of GS induced by phosphodiesterase (EC 3.1.4.1 ). Increases in the activities of nitrile hydratase and amidase and resistance of these enzymes to ammonium were observed in mutant ofR. rhodichrous resistant to phosphotricine, an inhibitor of GS. An important role of GS in the mechanism of adaptation is suggested.     

2D format for screening bacterial cells at the throughput of flow cytometry

We present a method for generating gel-based unordered 2D arrays of bacterial cells of a very high density, up to 10(5) cells per mm(2). Bacteria in a suspension are focused into a thin layer when the suspension and a dry gel matrix penetrate each other. Formation of a second gel from gel-forming components contained in the suspension results in immobilization of the cells. The immobilized cells stay alive and can repeatedly divide to produce microcolonies. The method provides for high-throughput screening and massively parallel analysis of individual cells in large populations, as well as for rapid isolation of rare clones.     

A novel structural tree for wrap-proteins,a subclass of (α+β)-proteins

In this paper, a novel structural subclass of (α+β)-proteins is presented. A characteristic feature of these proteins and domains is that they consist of strongly twisted and coiled β-sheets wrapped around one or two α-helices, so they are referred to here as wrap-proteins. It is shown that overall folds of the wrap-proteins can be obtained by stepwise addition of α-helices and/or β-strands to the strongly twisted and coiled β-hairpin taken as the starting structure in modeling. As a result of modeling, a structural tree for the wrap-proteins was constructed that includes 201 folds of which 49 occur in known nonhomologous proteins.