Ultrasound in phage display: a new approach to nonspecific elution

Libraries of phage-displayed random peptides are routinely used to identify target-binding peptides. Phages are commonly eluted in a nonspecific manner, especially if there are no available ligands of the particular target to use as competitors. However, the present study clearly demonstrates that nonspecific elution is not always able to break peptide-target interactions. To circumvent this we have developed an improved nonspecific elution strategy that uses ultrasound to release target-bound phages and enables selection of high-affinity clones in a single step.     

Sorption of wheat seed lectin by polyelectrolyte complexes of chitosan

The possible application of polyelectrolyte complexes (PEC) of chitosan and copolymers of maleic acid with N-vinylpyrrolidone, styrene, and ethylene and/or chitin cross-linked sorbents (CCLS) synthesized on the basis of PEC for sorption of wheat germ agglutinin (WGA) was studied. The synthesis of spherically granulated sorbents was shown. Compared to unmodified chitosan, there was a significant increase in sorption of WGA by the PEC: PEC, 2.5-fold, and CCLS, from 3.5-fold to 7-fold.     

Comparative characteristics of systemic and pulmonary hemodynamics during changes in the heart preloading

A greater degree of relative shifts in the systemic arterial pressure in enhancing the right heart pre-load as compared with its diminishing. A primary role of the compensation mechanisms of the enhanced systemic arterial pressure level. The main role in the compensation of integral shifts of the arterial pressure induced by changes in the heart pre-load was shown to belong to the vascular resistance both in the major and the minor circulation circles. An idea of a greater involvement of the capacity function of the vascular bed in the minor circulation circle as compared with that in the major circulation circle in systemic haemodynamic shifts in changes of the heart pre-load, has been advanced.     

RNA,unlike DNA,binds to aurintricarboxylic acid via covalent bonds: molecular-biological and spectroscopic evidence

A selective interaction of ATA with RNA, unlike DNA, when isolating nucleic acids from plant materials was established. The data concerning the binding strength of highly purified RNAATA and DNAATA preparations to nitrocellulose and nylon filters under conditions of high ionic strength are presented. The interrelation of ATA RNA-tropism and absence of adsorption capability of chemical modified RNAATA the backbone was observed. Using IR spectroscopy under the procedure of multi-broken complete light reflection, a formation of ATA and RNA complex was fixed via phosphoric-ether bond (P-O-C), which was absent in the case of DNAATA. The obtained data raise the problem of RNAATA application in molecular biology experiments.     

Construction of vector plasmids for the Plectonema boryanum cyanobacterium and creation,on such basis,of the vector-host system

The plasmid composition of the Plectonema boryanum Gom. Cyanobacterium, strain CALU 465, was analyzed. A small pSM1 plasmid, size 1.5, was chosen for genetic engineering. The physical map, constructed for the plasmid, was used to create the pSTS series, i.e. vector construction for the P. boryanum cyanobacterium. A method was selected and tested for the introduction of the vector into host cells. The needed orientation of pSM1 cyanobacterium plasmid within the vector as well as a possible role of its separate elements in inheriting the construction by host were defined.     

Affinity selection to papain yields potent peptide inhibitors of cathepsins L, B, H, and K

Endogenous cysteine proteases were given much attention lately, as their role in a variety of pathophysiological disorders became evident. Amongst them cathepsins, which are thought to be implicated in mediation of osteoporosis, cancer progression, atherosclerosis, and many other conditions, are of considerable interest as drug targets. In the presented work, papain was chosen as a model cysteine protease and panning protocol was optimized for selection of papain-binding phage-displayed peptides from a commercially available combinatorial peptide library. Different selection strategies were applied in order to select high-affinity binders. Ultimately, five cyclic peptides (CNWAAGYNCGGGS-NH2, CWSMMGFQCGGGS-NH2, CWEWGGWHCGGSS-OH, CNWTLGGYKCGGGS-NH2 (all cyclized through formation of intramolecular disulphide bond), and GNWTLGGYKGG (cyclized head-to-tail)) were synthesized and tested for inhibitory activity towards papain and human cathepsins L, B, H, and K. The peptides possess inhibitory constants in the low micromolar to mid-nanomolar range and exhibit certain selectivity for different lysosomal cysteine proteases included in this study.     

The peculiarities of fluorescence of natural steroid hormones, excited by a laser source of the UV range

The data of studies were summarized that demonstrated for the first time the fluorescence of the members of all classes of steroid hormones. The fluorescence spectra were characterized, the relative fluorescence quantum yields were estimated, and the dependence of the intensity and spectrum of fluorescence on the presence and position of side groups and double bonds in the molecule of the hormone was established.     

Anaerobic bacteria in the gut of terrestrial isopod crustaceanPorcellio scaber

Anaerobic bacteria from Porcellio scaber hindgut were identified and, subsequently, isolated using molecular approach. Phylogenetic affiliation of bacteria associated with the hindgut wall was determined by analysis of bacterial 16S rRNA gene sequences which were retrieved directly from washed hindguts of P. scaber. Sequences from bacteria related to obligate anaerobic bacteria from genera Bacteroides and Enterococcus were retrieved, as well as sequences from 'A1 subcluster' of the wall-less mollicutes. Bacteria from the genus Desulfotomaculum were isolated from gut wall and cultivated under anaerobic conditions. In contrast to previous reports which suggested the absence of anaerobic bacteria in the isopod digestive system due to short retention time of the food in the tube-like hindgut, frequent renewal of the gut cuticle during the moulting process, and unsuccessful attempts to isolate anaerobic bacteria from this environment our results indicate the presence of resident anaerobic bacteria in the gut of P. scaber, in spite of apparently unsuitable, i.e. predominantly oxic, conditions.     

Modulation of proliferation of peripheral blood lymphocytes after irradiation of volunteers with polychromatic visible and infrared light

Effects on human immune system of visible and infrared (IR) radiation, the dominating types of solar light on Earth, still remain poorly studied. In the present work, a small area of the volunteers' body surface was irradiated with polychromatic visible + IR polarized (VIP) light, whose spectral range is close to the natural one (400-3400 nm, 12 J/cm2), and spontaneous and phytohemagglutinin (PHA)-induced DNA syntheses were studied by radiometric method in lymphocytes (Lym) of peripheral blood. This Irradiation stimulated both spontaneous and PHA-induced DNA synthesis in Lym but only in volunteers with initially decreased parameters of synthesis (on average, by 2.5 and 2.7 times, respectively), which was recorded 24 h after irradiation of volunteers, and after a 72 h cultivation of separated mononuclears. In the parallel experiments, blood of each volunteer was irradiated in vitro. Besides, by modeling situation in vivo, when a small amount of transcutaneously photomodified blood contacts its much larger circulating volume, the irradiated and non-irradiated samples of autologous blood were mixed at a 1:10 volume ratio. In Lym with the initially decreased synthesis level, the spontaneous synthesis elevated by 2 and 3 times, respectively, whereas stimulation of PHA-synthesis was observed only after addition of the irradiated blood to the intact one (by 2.2 and 1.6 times, respectively). A high degree of positive correlation in changing the studied parameters is revealed in irradiation of blood in vivo and in vitro. This makes it possible to associate the light-stimulating effect on Lym of the entire circulating blood with transcutaneous photomodification of its small amounts, and with action of such blood on the rest of blood. A similarity in the direction and additivity of mitogenic effects of VIP light and PHA was revealed. The obtained data enable us to suggest that therapy employing polychromatic visible and IR light would promote presumably an increase in the number of Lym in peripheral blood and an enhancement of their response to antigenic stimulus.