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A general scheme for the synthesis of ribonucleotide monomers containing alkoxymethyl group in 2'-O-position for the solid-phase phosphotriester oligonucleotide synthesis using O-nucleophilic intramolecular catalysis has been developed. In particular, the monomers containing 2'-O-modifying 2-azidoethoxymethyl, propargyloxymethyl, or 3,4-cyclocarbonatebutoxymethyl groups has been prepared.

An efficient synthetic method for monomer ribonucleotide synthons containing 2'-O-methoxymethyl and 2'O-(p-nitrobenzyloxy)methyl groups used for oligonucleotide phosphotriester method with O-nucleophilic intramolecular catalysis at the stage of formation of internucleotide bond is developed. It is shown that synthons containing protecting 2'-O-(p-nitrobenzyloxy)methyl group may be used for automatic synthesis of phosphotriester oligoribonucleotides with high yields and synthons containing methoxymethyl group--to get 2'-O-modified oligonucleotides.

Conjugate the fluorescent dye 4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indatsen-8-propionic acid (BODIPY) and N2,N4,N6-trimethylmelamine was obtained. It was shown that this compound in the presence of formaldehyde generates covalent cross-links of DNA strands in vitro.

This review includes literature data on main types of reagents inducing covalent cross-links of nucleic acids. Reactivity of cross-linking agents, preferable sites for their binding, and methods for determination of location of cross-links in duplex are discussed. Biological responses of cells to cross-linking in nucleic acids, i.e. replication and transcription blocking, onset of repair processes, and apoptotic cell death are considered, as well as application of cross-linking reagents as medicinal drugs for solving molecular-biological problems.

In order to improve physicochemical and biological properties of natural oligonucleotides in particular increasing their affinity for nucleic acids, the selectivity of action and biological sustainability, several types of DNA mimics were designed. The survey collected data on the synthesis and properties of the DNA mimics - peptide-nucleic acids analogues, which are derivatives of pyrrolidine and hydroxyproline. We examine some physicochemical and biological properties of negatively charged mimics of this type, containing phosphonate residues, and possessing a high affinity for DNA and RNA, selective binding with nucleic acids and stability in various biological systems. Examples of the use of these mimics as tools for molecular biological research, particularly in functional genomics are given. The prospects for their use in diagnostics and medicine are discussed.

An effective modification of phosphotriester method for automatic synthesis of DNA and RNA fragments using O-nucleophilic intramolecular catalysis and 2-(azidometil)benzoyl group to protect amino groups of heterocyclic bases of nucleotides is described.

Published data on the main types of reagents capable of introducing covalent interstrand cross links into nucleic acids (NA) are summarized in the present review. The reactivity of cross-linking agents, their preferred binding sites, and methods of determining the cross-link localization in a duplex are discussed. Cell response to DNA cross linking, namely, the blocking of replication and transcription, the initiation of reparation processes, and apoptotic death of the cell, are analyzed, as well as the use of cross-linking reagents in therapy and molecular biology.

The azidomethyl and 2-(azidomethyl)benzoyl as 2'-OH protecting groups are reported for preparation of oligoribonucleotides by the phosphotriester solid-phase method using O-nucleophilic intramolecular catalysis. The procedures for the synthesis of the corresponding monomer synthons were developed and the usefulness of the application of 2'-O-azidomethyl and 2'-O-2-(azidomethyl)benzoyl groups was examined in the synthesis of different RNA fragments with a chain length of 15-22 nucleotides. The azidomethyl group was found to be more preferable for effective synthesis of oligoribonucleotides. Hybridization properties of RNAs toward their complementary oligonucleotides were examined before and after the removal of 2'-O-azidomethyl groups.

Morpholino phosphorodiamidate (MO) DNA mimics display excellent water solubility and hybridization properties toward DNA and RNA, and have been utilized in the model vertebrate zebrafish (Danio rerio) for genome-wide, sequence-based, reverse genetic screens during embryonic development. Peptide nucleic acids (PNAs) exhibit excellent mismatch discrimination, nuclease resistance, and protease resistance, but low solubility. Negatively charged DNA mimics composed of alternating residues of trans-4-hydroxy-L-proline peptide nucleic acid monomers and phosphono peptide nucleic acid monomers (HypNA-pPNA) combine all of the positive features of both MOs and PNAs. Thus, we evaluated PNA oligomers and HypNA-pPNA oligomers as an alternative to MOs for oligonucleotide inhibition of gene expression in zebrafish embryos. We observed that HypNA-pPNA 18-mers displayed comparable potency to MO 25-mers as knockdown agents against chordin, notail and uroD, with greater mismatch stringency. Furthermore, we observed that a specific HypNA-pPNA 18-mer elicited the dharma (bozozok)(-/-) phenotype in zebrafish embryos, which MO 25-mers do not. These observations validate HypNA-pPNAs as an alternative to MO oligomers for reverse genetic studies. The stronger hybridization and greater specificity of HypNA-pPNAs enable knockdown of mRNAs unaffected by MO oligomers.

An effective procedure for specific determination of the cap structure at the 5'-terminus of mRNA and for isolation of the corresponding full-length cDNA has been developed. The procedure involves covalent attachment of an oligonucleotide template extender to the 5'-cap structure of mRNA followed by RT-PCR using M-MLV SuperScript II reverse transcriptase. In the course of reverse transcription, the enzyme 'jumps over' the cap structure and includes the sequence complementary to the oligonucleotide template extender into the 3'-end of the first cDNA strand. The cap-jumping method was successfully tested using some mammalian cellular mRNAs, genomic RNAs of tobacco mosaic virus (TMV) U1 and the recently isolated crucifer-infecting tobamovirus. Moreover, cDNA products corresponding to the genomic tobamovirus RNA were obtained from total RNA extracted from tobacco plants infected by crucifer-infecting tobamovirus or tobacco mosaic virus. Using the cap-jumping method, we have shown for the first time that genomic crucifer-infecting tobamovirus (crTMV) RNA contains a 5'-cap structure. This improved method can be recommended for the construction of full-length and 5'-end enriched cDNA libraries, identification of capped RNAs and determination of their 5'-terminal sequences.

Effects of low activity of test-subjects during antiorthostatic hypokinesia on the intragroup structure as well as the semantic composition and the directionality of estimation criteria selected by test-subjects to describe the system of attitudes to oneself and others, and their impact on individual status in the social structure of the group have been studied. It was shown that maintaining of a definite level of individual activity of members is important for the group structure and successful adaptation of test-subjects to the unfavourable factors of hypokinesia. The degree of the ego image integrity and dominance of criteria that infer empathy and positive feelings within the system of individual appraisements determine the social status of a group member. The psychologic signs of a "apet" (psychologically close) and a "outsider" (psychologically strange) members of the group have been revealed.

Two types of oligonucleotide mimics relative to peptide nucleic acids (PNAs) were tested as probes in nucleic acid hybridisation assays based on polyacrylamide technology. One type of mimic oligomers represented a chimera constructed of PNA and phosphono-PNA (pPNA) monomers, and the other one contained pPNA residues alternating with PNA-like monomers on the base of trans -4-hydroxy-L-proline (HypNA). A chemistry providing efficient and specific covalent attachment of these DNA mimics to acrylamide polymers using a convenient approach based on the co-polymerisation of acrylamide and some reactive acrylic acid derivatives with oligomers bearing 5'- or 3'-terminal acrylamide groups has been developed. A comparative study of polyacrylamide conjugates with oligonucleotides and mimic oligomers demonstrated the suitability and high potential of PNA-pPNA and HypNA-pPNA chimeras as sequence-specific probes in capture and detection of target nucleic acid fragments to serve current forms of DNA arrays.

Approaches to preparing acrylamide and polyacrylamide conjugates with oligonucleotides and some peptide nucleic acid-related DNA mimics are considered. Their physicochemical properties and application to the nucleic acid analysis are discussed.

The objective of this paper is to describe psychological phenomena which has developed in the course of inter- and intragroup interaction in space. Several objective reasons are stressed which comprise the basis of the formation of the majority of the psychological phenomena. The authors also discuss prediction of these phenomena, namely, can they occur on the International Space Station (ISS) and what countermeasures will prevent them. In the analysis, the authors rely on the practice of prolonged spaceflight (PSF) psychological support in Russia; preliminary results of several flights within the Mir/NASA project; the personal experience of cosmonaut Valery V. Polyakov; and data gained during prolonged studies simulating PSF conditions (isolation, microgravity, etc.).

The synthesis of a series of DNA mimics--peptide nucleic acids, phosphonate analogues of peptide nucleic acids, and their hybrids--is described. The preparative synthesis of the corresponding monomers and the solid phase automated synthesis of oligomers-mimics are developed. Modified phosphonate analogues of peptide nucleic acids, in particular chiral derivatives and those with additional hydroxyl groups in the side chains of the backbone as well as pyrene derivatives of peptide nucleic acids and their phosphonate analogues, are prepared. The ability of the resulting oligomers specifically to hybridize to DNA and RNA complementary chains is studied. It is shown that phosphonate analogues of peptide nucleic acids and their hybrids with peptide nucleic acids can form complexes with the DNA and RNA complementary strands, the stability of the complexes increasing in parallel with the increase in the number of peptide nucleic acid residues in the chain of the mimic. This property, along with good water solubility, provides the precondition for further evaluation of these compounds as antisense and antigene agents.

Background: The interactions of individuals participating in space simulation studies can give us valuable information about ways that space crew members relate with one another. A promising method of investigating such interactions is based on the Kelly repertory grid technique., Hypotheses: We predicted that in a space simulation crew: 1) one's personal self-concept would become closer to concepts about other crew members in a cohesive crew, and vice-versa, and 2) the similarity of one's ego images in the past, present and future influences that person's position in the group., Method: Crews from two isolation studies lasting 135 and 90 days at the Institute for Biomedical Problems in Moscow were evaluated using a modification of the Kelly repertory grid technique. Members assessed each other on a monthly basis and during off-nominal simulated docking periods., Results: During both isolations, crew members were unsuccessful in making their personal self-concepts move closer to their concepts about fellow crew members. Crew disintegration resulted, with one member becoming an outsider whose personality was characterized by a disintegrated ego-image and an infantile type of the present ego., Conclusions: In small isolated groups, failure to make personal self-concepts become more like concepts about other crew members can lead to group disintegration and tension and can result in the appearance of an outsider who has a disintegrated ego-image and an infantile present ego.

Thymidine oligonucleotide analogues with phosphodiester bonds fully substituted by carboxamidomethyl phosphonamide, or glycinamide linkages were synthesized on a solid support, and their hybridization properties toward DNA and RNA targets were determined by Tm analysis.

In an attempt to improve physico-chemical and biological properties of peptide nucleic acids (PNAs), particularly water solubility and cellular uptake, the synthesis of chimeric oligomers consisted of PNA and phosphono-PNA analogues (pPNAs) bearing the four natural nucleobases has been accomplished. To produce these chimeras, pPNA monomers of two types containing N-(2-hydroxyethyl)phosphonoglycine, or N-(2-aminoethyl)phosphonoglycine backbone, were used in conjunction with PNA monomers representing derivatives of N-(2-aminoethyl)glycine, or N-(2-hydroxyethyl)glycine. The oligomers obtained were composed of either PNA and pPNA stretches or alternating PNA and pPNA monomers. The examination of hybridization properties of PNA-pPNA chimeras to DNA and RNA complementary strands in comparison with pure PNAs, and pPNAs as well as DNA-pPNA hybrids and DNA fragments confirmed that these chimeras form stable complexes with complementary DNA and RNA fragments. They were found to be resistant to degradation by nucleases. All these properties together with good solubility in water make PNA-pPNA hybrids promising for further evaluation as potential therapeutic agents.

Two convenient, practical routes to the synthesis of non-nucleotide bridged cyclic oligonucleotides have been developed. The first procedure included circularization of oligonucleotides by template-directed ligation on solid phase, while the second procedure involved preparation of a circular oligomer by non-template chemical ligation of a linear precursor in solution. Using these approaches, a series of single- and double-stranded cyclic oligonucleotides with non-nucleotide bridges has been synthesized.

Background: The communication between space crews and outside monitoring personnel in Mission Control gives us valuable information about crewmember psychological health. Studying the formal parameters of similar communication during ground-based space simulation missions helps us understand the psychological climate of confined groups over time, and this information can be applied to long-term space missions., Hypotheses: We hypothesized that psychological closing and information filtration will be observed in a confined crew as the mission progresses and will differ by the type of communication (e.g., audio vs. computer-generated) with the outside monitors in the simulated Mission Control (MC). In addition, communication patterns will vary with the specific group of people on-duty outside., Method: Audio and computer communications between space simulation crews and MC teams were analyzed during two isolation studies lasting 135 and 90 d at the Institute for Biomedical Problems in Moscow. A number of temporal, content and quantitative parameters of verbal activity were examined., Results: The total intensity of communication dropped after month 1 of the missions. The Commander had the highest intensity of communication. There was evidence for the presence of psychological closing and information filtration in the crews over time, with some variation based on type of communication. Communication patterns differed with different outside teams., Conclusions: The communication between confined groups and outside monitoring personnel is affected by psychological closing and information filtration and by the make-up of the teams that comprise the monitoring groups.

The Tth DNA polymerase genes from the thermophilic bacterium Thermus thermophilus (strans HB-8 and Tt-111) were cloned and expressed in Escherichia coli cells. The target protein contained a polyhistidine tag at the N-terminus that allowed its single-stage isolation by affinity chromatography on Ni-NTA-agarose. The isolated enzyme displayed both high DNA polymerase and reverse transcriptase activities.

In experiments HUBES and ECOPSY-95 small groups of test-subjects under the conditions of long-term isolation and confinement were noted to split into two fairly stable parts each consisting of two crew members and an "outsider". Strain in the interaction between the "outsider" and the crew tended to grow in acuity as was evidenced by rise in the criteria describing behavior of a small group, and relationship. In both experiments the background for the conflict-threatening strain appeared to be a disintegrated ego-image in both of the "outsiders". Generally, infantilism of ego-image was in hand with hand with low self-assessment. Development by the subjects of ineffective patterns of the attitude system which we consider to be "escape back to the past" and "disintegration" of ego-image overlapped with the most psychologically challenging periods in the experiments, i.e. the start and the end of isolation and confinement, and off-nominal situations.

Dynamics of mental performance, critical periods of adaptation, and cognitive processes were studies in conjunction with extended experimental isolation. Training to simple motor skills was found to be less impeded by prolonged isolation as opposed to operations requiring active involvement of higher psychic functions (memory, concentration, thinking). Experiments HUBES and ECOPSY strengthened the hypothesis concerning possible advent of critical periods in prolonged isolation impacting mental performance. They are the initial period (week 1 in isolation), emergency, arrival of visiting crews, and finishing two weeks. Effect of isolation was not so much evident from changes in absolute meanings of work parameters as from the reduction of their stability in time.

Analyzed were indices of communicative activity of crew members during audio- and computer sessions in order to assess status and effectiveness of communicative interaction of crew with external parties. The investigation gave another evidence that an isolated small group develops "closing" and "internal censorship" in contacts with outer personnel. The conclusion was based on limited in intensity, number, topical spectrum and outer companion preference communication. These appeared to be parallel to egocentrism manifested by claims on supreme concern, sensitivity to speech tones and matter of massages of outer supporters, and attempted manipulation with the outer personnel. In the course of the experiment, the subjects were getting more into the habit to use the information channels for expansion of their emotional contacts and "dumping" emotions. Differential attitude to different duty teams and selective manner of communication underlie differences in the intensity of crew-ground personnel communication.

To verify experimentally the molecular recognition theory, plasmids were constructed that provided the efficient synthesis of hybrid proteins composed of human calcitonin or miniproinsulin, the corresponding antisense peptides, and a histidine-rich metal-binding peptide. A method for isolation of the hybrid proteins by metal-chelating chromatography, cleavage, and renaturation was developed.

Chemicoenzymatic synthesis and cloning of a gene encoding the Fc domain of human immunoglobulin G1 were carried out. The artificial gene was expressed in Escherichia coli cells in plasmid vectors under control of a late T7 promoter. The recombinant protein isolated from the bacterial cells is capable of forming dimers and binding protein A from Staphylococcus aureus.

The aim of this study was to investigate changes in the psychological state of the crew members and the needs for psychological support during prolonged isolation. For the purpose methods employed that have been widely used in psychological evaluation during Soviet spaceflights. Communication between Commander and Crew Interface Coordinator (CIC) was analyzed. Crew disposition was observed and analyzed for information about the process of group formation and the role of each crew member in this process. Operation of the CIC's was investigated for evidence of a psychological support function. During isolation certain adaptive changes in communication took place: (1) use of unplanned contacts and intensive contacts with a preferred ground crew member, (2) resistance to penetration in the life of the crew (increase of aggressive statements and self-justifications, reduction of report length and claims), and (3) closing communication to "outsiders" by using a special code and decreasing discussion of problems. A process of group formation was noted in the course of isolation, but the final structure of the group was not stable. The relations of subjects B, D and G were crucial in the creation of an effective crew. The woman in the crew was never involved in conflicts and acted as a peacemaker. The crew regarded the communication channel between Commander and CIC as belonging to the entire crew for expressing feelings about crew relations, administration and services, and the CIC can provide needed psychological support, confirming earlier experience from Soviet simulated and actual spaceflights.

The aim of this study was to investigate the effects of prolonged isolation on the higher psychic functions, like working memory, attention concentration, and intellect (problem solving and decision making), and on sensory-motor skills and stress resistance. Previous Soviet simulation studies and the ISEMSI isolation experiment have indicated that prolonged isolation can affect higher psychic functions. A set of psychological tests in the form of a computer game was presented each workday to the chamber crew and to the ground crew serving as a control group. In analyzing the data it was taken into account that performance can be affected not only by the influence of isolation, but also by a learning process and by subject motivation. In addition, a distinction was made between absolute score and stability (range) of the score. Analysis of the chamber crew's work capability as a function of time showed the occurrence of three distinct periods of adaptation: (1) a period of acute adaptation in week 1, (2) a period of stable adaptation during weeks 3-6, and (3) a period of "final effort" in weeks 8-9. While in general the effect of isolation on the absolute scores was minor, larger ranges for the scores in "working memory," "attention concentration," and "calculation under time deficit" tests are an indication of increased instability, probably due to stress resistance. The 4 female subjects of the combined groups scored significantly higher than the 5 males in "attention concentration/distribution," "spatial orientation," "intuition in visual search," and "logical decision making under time deficit." Males presented higher scores in "calculation under time deficit" and working memory, and higher stability in "attention concentration" and "calculation under time deficit."

A set of new sulfurizing agents representing disulfides of arylsulfonic acids has been developed for the automated synthesis of phosphorothioate oligonucleotide analogues via the phosphoramidite method. These reagents, such as bis(benzenesulfonyl)disulfide, bis(p-toluenesulfonyl)disulfide, bis(p-methoxybenzensulfonyl)disulfide, and bis (p-chlorobenzenesulfonyl) disulfide, are easily prepared crystalline solid compounds. They are relatively inexpensive, easy to handle, and efficiently convert internucleotide cyanoethyl phosphite to the phosphorothioate triester within 1-2 min. The efficiency of phosphorothioate oligonucleotide synthesis with the use of these reagents is comparable to that of phosphodiester oligonucleotides.

Plasmid vectors providing a high level expression in Escherichia coli cells of genes for heterologous polypeptides and proteins fused to peptides containing homohistidine clusters have been constructed. The obtained vectors have been used to achieve expression of genes for streptavidin, proinsulin and calcitonin. The hybrid proteins were isolated by affinity chromatography on Ni-agarose columns.

Described is a computerized technique for assessment of psychic performance. It includes a battery of tests in the form of computer games to score recent memory, attention, cognitive power, spatial awareness, and oculomotor orientation. The game-type tests and the possibility of feedback enforce motivation for diagnostic testing. The technique can be advantage for artificial or extreme environments as it can be fulfilled by subjects themselves without assistance of expert.

Genomic RNA sequence of a tobamovirus infecting cruciferae plants (cr-TMV) was determined. The RNA is composed of 6312 nucleotides and contains four ORFs encoding the proteins of 122K (ORF1), 178K (ORF2), 29K (ORF3) and 18K (capsid protein, ORF4). ORF4 overlaps ORF3 by 74 nucleotides and the overlapping region can be folded into a stable hairpin structure. The 3'-terminal region of the cr-TMV RNA preceding the tRNA-like structure was shown to form six potentially stable pseudoknots.

The barley chloroplast psbA gene encoding D1 protein, one of the main photosystem II components, has been over-expressed in E. coli cells. The existance of two in vivo expression products, a protein with M(r) about 33.5 kDa, corresponding to the full-length precursor of the 32 kDa D1 mature form, and a truncated 29 kDa polypeptide was revealed. A modified D1 protein containing six histidine residues at the carboxy-terminus was also obtained. After isolation and renaturation, the ability of the recombinant D1 protein to bind atrazine and pigments from barley thylakoids was demonstrated.

Recombinant constructs expressing fusion (His)6 movement proteins of two strains (Cruciferous and Vulgare) of tobacco mosaic virus were generated by cloning the PCR-amplified fragments into the pQE-9 vector. The movement proteins containing N-terminal (His)6 affinity tags were purified on a metal chelate adsorbent.

Because of the potential significance of the 'molecular recognition' theory for studies in molecular biology and biotechnology, the theory is worth being examined using methods of chemical-enzymatic gene synthesis, recombinant DNA construction and microbiological peptide synthesis. We therefore undertook the synthesis of human Va18-calcitonin, miniproinsulin, and the corresponding antisense peptides as model compounds. In designing an experimental system the idea was to combine sense and antisense polypeptides into a single chain and to examine their intramolecular interaction. In this paper the chemical-enzymatic synthesis, cloning and expression of the genes for calcitonin, miniproinsulin, the corresponding antisense peptides and their combinations are described. The recombinant DNAs obtained were able to direct in vivo expression of the target polypeptides as hybrid proteins with the IgG-binding domain of the staphylococcal A protein in bacterial cells.

Previously characterized by us barley chloroplast psbA gene, which encodes one of the main Photosystem II components--D1 protein, has been inserted in a set of special plasmid vectors and its expression in vitro and in vivo has been investigated. Experiments on the in vitro expression in the rabbit reticulocyte lysate system revealed a major product with a molecular weight ca. 33.5 kD, which corresponds to the unprocessed D1 barley protein. A lower molecular weight protein (about 29 kD) was also observed. These results are in agreement with the existence of two potential translation start sites in the psbA gene in the same reading frame, the second one starting from Met37 residue. The results fully correlate with the earlier data on the in vitro expression of psbA genes of maize, pea, and tobacco. Experiments on the in vivo expression of psbA gene in E. coli cells with the above constructions also revealed proteins with m. w. about 33.5 and 29 kD. The yield of the target recombinant protein in some cases was about 25-30% of the total E. coli cellular protein. The correspondence of the bands to the desired products was proved by the immunoenzyme analysis with the use of polyclonal antibodies. The data obtained show for the first time the construction of E. coli strains producing recombinant D1 protein of cereals in a high level.

Dipentafluorophenyl carbonate has been successfully used as condensing agent for the internucleotide bond formation in the synthesis of oligonucleotides via H-phosphonate approach. The mechanism of a nucleotide component activation with this reagent has been investigated with the help of 31P NMR spectroscopy. It was shown that preactivation of deoxynucleoside H-phosphonate with dipentafluorophenyl carbonate has no influence on the efficiency of the synthesis. This reagent is highly reactive, nonhygroscopic and stable on storage at room temperature. The effectiveness of dipentafluorophenyl carbonate in the oligonucleotide chemistry has been demonstrated in the solid-phase synthesis of 10-50-mers on 0.2, 1 and 10 mumol scales. The use of this reagent for the derivatisation of polymer supports as well as for the synthesis of oligonucleotide conjugates with polyethylene glycol and a lipid is described.

A rapid method for the removal of protecting groups from synthetic oligodeoxyribonucleotides, obtained by the phosphoroamidite and H-phosphonate methods, including the use of hydrazine solutions has been developed. The combination of this procedure with the application of isopropoxyacetyl N-protecting group and oxalyl ester linkage for the first nucleoside attachment to the polymer support allows to reduce to several minutes the time needed for the full oligonucleotide deprotection.

The chemical-enzymatic synthesis of a gene coding for A2B2 repeats of the albumin-binding domain of streptococcal protein G has been accomplished. The codon usage of the natural gene has been modified to adapt an artificial sequence for the efficient translation in E. coli. The gene (238 b.p.) was cloned in the polylinker plasmid pUCL1 and then fused in frame to the 3'-terminus of the gene for the IgG-binding domain of staphylococcal protein A, which was earlier cloned in the expression plasmid pUCL2. A fused polypeptide composed of the E and B domains of protein A and A2B2 repeats of protein G was produced in E. coli cells under the lac promoter control. The resulted product was isolated by affinity chromatography on IgG-sepharose and (or) albumin-sepharose.

Mutagenesis of two previously cloned plant genes, maize storage protein cZ22B1 gene and barley Photosystem II protein D1 gene (psbA), was carried out. To improve the nutritional quality of zein, the DNA region corresponding to the protein sixth alpha-helix rod was substituted by a synthetic segment bearing three codon changes for Lys. Additional stabilization of this helix was achieved by three more codon changes for Glu. By means of oligonucleotide directed mutagenesis five different copies of psbA gene were obtained, bearing single codon change of Ser264 (wild type) for Gly, Ala, Cys, Asn, and Thr, respectively. These constructs can be used for studying functional topography of protein D1 and core region.

The authors review an expert system (ES) of diagnosing the prosthetics quality, elucidate problems of the ES functioning within the framework of the general ES. Special attention is paid to the description of the knowledge and datum surface, to the algorithms of direct and reverse illegible logical data output in taking decisions as to defects of the patient's prosthesis in accordance with the signs observable. The work of the ES is demonstrated with special reference to concrete cases. Analysis is made of the estimates of the sensitivity to the initial data. The ES presents knowledge in depth, being designed in two versions: for practical (individual and mass) prosthetics and training purposes.

In order to determine structures of the barley photosystem II subunits, the following genes have been cloned: psbB, encoding 47 kDa chlorophyll-binding subunit; psbH, encoding 7.7 kDa phosphoprotein; psbE and psbF, encoding 9.3 and 4.4 kDa subunits of the cytochrome b559 apoprotein, respectively; and a fragment of psbC gene, encoding the 43 kDa chlorophyll-binding subunit. The nucleotide sequences of these genes and the deduced amino acid sequences of their products are highly homologous to the corresponding sequences for other plant species.

The authors describe the structure, characteristic features and experience gained with the employment of an expert system for the choice of hip prostheses (in cases of unilateral amputation) and assessment of the prosthetics quality. Word the requirements for hardware and software, present functional subsystems corresponding to certain interrelated stages of prosthetics. A variant has been devised of an appropriate training expert system with a profound representation of intelligence in an object area.