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Respiratory chain of alkalophilic bacteria. Annual progress report, June 15, 1981-May 15, 1982

Description: In view of the increased energy cost of life at extremely alkaline pH, the extraordinary qualitative and quantitative array of respiratory chain components of alkalophilic bacteria, and the normal growth yields and O/sub 2/ consumption rates of such organisms, it has been proposed that the obligately alkalophilic bacteria possess structural/functional properties of the respiratory chain such that particularly efficient energy conservation is facilitated. The respiratory chain components of Bacillus alcalophilus have been studied in comparison with its non-alkalophilic mutant derivative; a similar study of Bacillus firmus RAB and non-alkalophilic RABN is now partially completed. The alkalophiles contain high quantities of many distinct redox carriers as compared to their derivative and other non-alkalophiles. Determinations of H/sup +/7O ratios are now in progress. A system for study of the regulation of cytochrome expression, as a function of pH, has been developed. Failure of obligate alkalophiles to grow at pH 7.0 now appears to relate to the low membrane potentials produced by respiration at that pH, rather than a failure of pH homeostasis. Since alkalophilic cells are found to be viable at pH 7.0, incubations can be conducted for study of functional and regulatory aspects of respiration.
Date: January 1, 1982
Creator: Krulwich, T.A.
Partner: UNT Libraries Government Documents Department

Rapid microbial identification by circular intensity differential scattering

Description: Circular Intensity Differential Scattering (CIDS) is one of the few really new approaches to microbial identification to have come into existence in the past several decades. The CIDS spectra can be measured as a function of wavelength, scattering angle, and/or matrix element, and a number of matrix elements can be measured virtually simultaneously. This panoply of measurements potentially gives the method resolving power for microbial identification. Some representative data taken over the past couple of years on CIDS spectra of several anti-viral vaccines is presented. 17 references; 9 figures.
Date: June 1, 1984
Creator: Gregg, C.T. & Salzman, G.C.
Partner: UNT Libraries Government Documents Department

Ames test results on shot-tank residues

Description: In August 1987, a routine Ames test on soot from the Lawrence Livermore National Laboratory (LLNL) 4-in. gun showed that the soot was mutagenic to Salmonella bacteria. Subsequent liquid chromatography on the soot showed that, out of hundreds of ultravoilet-absorbing compounds found in the residue, only three or four were mutagenic. When a sample large enough to weigh was collected, it was found that No environmentally identified complex mixture has ever been reported with as much Ames/Salmonella activity per gram as the gun residues.'' Since then, Ames tests of hundreds of samples have verified that the residues from our gun tanks may be hazardous to health. The actual degree of the hazard and the identity of the offending chemicals are still unknown. 2 refs.
Date: September 21, 1990
Creator: Bloom, G.H.
Partner: UNT Libraries Government Documents Department

Characterization of defective interfering RNAs associated with RNA plant viruses

Description: Our lab was the first to describe and characterize a defective interfering RNA (DI RNAs or DIs) in association with a small RNA plant virus. The features of the DIs that we discovered in infections of tomato bushy stunt virus were compatible with the properties of DIs identified in many animal virus infections. Animal virologists have generally recognized the importance of studying DIs because they are invaluable tools for identifying cis-acting sequences important in virus multiplication and because they offer the opportunity to elucidate mechanisms involved in viral persistence and disease attenuation. Hence our discovery offered a comparably valuable tool for use in plant virus studies for the first time. Since the original observation with TBSV, we discovered the second example of plant viral DI RNAs associated with turnip crinkle virus (TCV), and many other reports have now appeared characterizing DI and DI-like RNAs in other plant viral infections. We are seeking to improve our understanding of the mechanisms of DI generation and the precise nature of the RNA sequences necessary for DI replication and encapsidation. We also want to address the nature of the DI mediated symptom attenuation and interference effects in plants, and to determine the feasibility of using transgenic plants constitutively expressing DI RNAs for disease control. The progress made on each of these objectives is summarized along with the proposed experiments for the continuation period.
Date: January 1, 1993
Creator: Morris, T.J. (Nebraska Univ., Lincoln, NE (United States). School of Biological Sciences) & Jackson, A.O. (California Univ., Berkeley, CA (United States). Dept. of Plant Pathology)
Partner: UNT Libraries Government Documents Department

First description of a variant of E. coli lacking superoxide dismutase activity yet able to grow efficiently on minimal, oxygenated medium

Description: A strain of E. coli has been obtained which is completely lacking in superoxide dismutase activity and is able to grow efficiently on glucose minimal media being sparged with pure oxygen. While its genotype is unknown, it appears to have arisen from mutation (s) which complements the absence of sodAB gene products without introducing superoxide dismutase activity. 1 ref., 2 figs.
Date: January 1, 1987
Creator: Fee, J.A.; Niederhoffer, E.C. & Naranjo, C.
Partner: UNT Libraries Government Documents Department

Raman activity in synchronously dividing bacteria

Description: Using a spectrometer equipped with an optical-multichannel analyzer as the detector (OMA), we have observed the Stokes laser-Raman spectra of metabolically active Escherichia coli and Bacillus megaterium from 100 - 2100 cm/sup -1/. After lengthy investigation, no Raman lines attributable to the metabolic process nor the cells themselves were found. Previous Raman spectra of active bacteria cannot be used to support nonlinear theories in biology. 34 refs., 9 figs.
Date: January 1, 1985
Creator: Layne, S.P.
Partner: UNT Libraries Government Documents Department

Mechanisms of recombination and function of DNA in bacteria. Progress report, August 12, 1978-August 15, 1979

Description: Most work in the current period centered on the organization and transfer of two classes of drug-resistance determinants in pneumonococcus: (a) insertions of foreign DNA in the chromosome; and (b) plasmid carried genes. Major findings are: determinants for chloramphenicol and tetracycline resistance in some clinical isolates of pneumococcus are present as adjacent insertions of heterologous DNA into the normal chromosome. They are not carried on plasmids as are similar determinants in many species; pneumonococcus will support the growth of resistance plasmids from other streptococci, and these can be transformed into pneumococcus from lysates of S. faecalis (group D) or group B streptococcus; one of the plasmids that has been transformed into pneumococcus mediates a form of DNAse-resistant conjugal transfer among other streptococcal groups and also in pneumococcus. (PCS)
Date: January 1, 1979
Creator: Guild, W.R.
Partner: UNT Libraries Government Documents Department

Atomic force microscopy images of T4 bacteriophages on silicon substrates

Description: A new atomic force microscope incorporating microfabricated cantilevers and employing laser beam deflection for force detection has been constructed and is being applied to studied of biological material. In this study, T4 bacteriophage virus particles were deposited from solution onto electronic grade flat silicon wafers and imaged in air with the microscope. Microliter droplets of the solution were deposited and either allowed to dry or removed with blotting paper. The images show both isolated viruses and aggregates of various sizes. The external structure as well as strands believed to be DNA streaming out of the virus could be observed. The construction of the microscope and its performance are also described. 19 refs., 4 figs.
Date: August 1, 1991
Creator: Kolbe, W.F.; Ogletree, D.F. & Salmeron, M.B.
Partner: UNT Libraries Government Documents Department

Characterization of a 1,4-. beta. -D-glucan synthase from Dictyostelium discoideum

Description: Various aspects of research concerning Dictyostelium discoideum are presented. The initial focus of this project was upon: the characterization of potential probes for the cellulose synthase (antibody and nucleic acid), the determination of the cultural induction conditions of cellulose synthesis, the solubilization of the enzyme activity, the development of a non-inhibitory disruption buffer, the generation and isolation of mutant strains deficient in cellulose synthesis, and the development of the capability to determine the degree of polymerization of the in vitro product. I have briefly summarized our most significant findings with only selected data sets being shown in this report in the interest of brevity.
Date: January 15, 1992
Creator: Blanton, R.L.
Partner: UNT Libraries Government Documents Department

Multiparameter light scattering for rapid virus identification

Description: An instrument for making multiparameter light scattering (MLS) measurements from viral suspensions has been described. Calibration methods and a technique for the correction of artifacts were also presented. This measurement technique may have broad applications in cell biology in general and in virology in particular. It may be possible to use MLS to identify viruses directly from clinical specimens. 8 references, 7 figures.
Date: January 1, 1984
Creator: Salzman, G.C.; Grace, W.K.; McGregor, D.M. & Gregg, C.T.
Partner: UNT Libraries Government Documents Department

Instrument for virus identification by polarized light scattering: a preliminary report

Description: An instrument for the identification of biological macromolecules is described. The basis for the instrument is the measurement of circular intensity differential scattering, used as one element of a Mueller matrix. 5 references, 5 figures. (ACR)
Date: January 1, 1984
Creator: Salzman, G.C. & Gregg, C.T.
Partner: UNT Libraries Government Documents Department

Optical diffraction and spatial filtering of electron micrographs of biological materials

Description: Optical diffraction and spatial filtering methods have been used to determine the characteristics of periodic structures in many biological materials. The head shell of bacteriophage T4 was chosen for this study, since aberrations in the assembly of the shell due to mutation or changes in growth conditions lead to the formation of a variety of elongated tubular head forms. The lattice parameters of structures assembled at elevated growth temperatures by normal, wild-type T4 and by a mutant (regA) were analyzed using optical diffraction patterns obtained from electron micrographs. Spatial filtering procedures were used for the reconstruction of one-sided images to determine the characteristics of the head structures assembled under different growth conditions.
Date: January 1, 1980
Creator: Wever, G.H.; Dunn, P.; Wiberg, J.S. & Thompson, B.J.
Partner: UNT Libraries Government Documents Department

Investigation of the molecular mechanism of thermal tolerance in bacillus subtilis. Final report, August 15, 1980-August 14, 1981

Description: We have studied Bacillus subtilis, Bacillus pumilus and Bacillus caldolyticus to ascertain the molecular mechanism of the ability to growth at high temperatures. B. subtilus wild type strains grow in minimal salts medium at a mesophilic temperature (37/sup 0/C) but not at a thermophilic temperature (56/sup 0/C). However, they do grow at 56/sup 0/C in complex rich media. Analysis of their nutritional requirements revealed that these bacteria require pyridoxine or aspartic acid and threonine to grow at 56/sup 0/C indicating that they are temperature sensitive mutants. Furthermore, mutants of B. subtilis which are able to grow on minimal salts media at 56/sup 0/C can be readily isolated. Therefore, it appears that the lack of growth of the wild type strain in minimal salts media at 56/sup 0/C is due to the instability of an anabolic enzyme. In contrast to B. subtilis, B. pumilus has never been observed to growth above 50/sup 0/C. However, our studies show that mutants of B. pumilus and B. subtilis which grow at 68/sup 0/C can be easily isolated. The isolation of such mutants strongly supports the idea that one gene can determine the ability to grow at extreme temperatures.
Date: August 14, 1981
Creator: Yamamoto, N.; Alexander, J. & Ch'ih, J.
Partner: UNT Libraries Government Documents Department

Electron crystallography of PhoE porin, an outer membrane, channel- forming protein from E. coli

Description: One approach to studying the structure of membrane proteins is the use of electron crystallography. Dr. Bing Jap has crystallized PhoE pore-forming protein (porin) from the outer membrane of escherichia coli (E. coli) into monolayer crystals. The findings of this research and those of Jap (1988, 1989) have determined these crystals to be highly ordered, yielding structural information to a resolution of better than 2.8 angstroms. The task of this thesis has been to collect and process the electron diffraction patterns necessary to generate a complete three-dimensional set of high resolution structure factor amplitudes of PhoE porin. Fourier processing of these amplitudes when combined with the corresponding phase data is expected to yield the three-dimensional structure of PhoE porin at better than 3.5 angstroms resolution. 92 refs., 33 figs., 3 tabs. (CBS)
Date: November 1, 1989
Creator: Walian, P.J.
Partner: UNT Libraries Government Documents Department

(Physiology and genetics of metabolic flux control in Zymomonas mobilis)

Description: The funded research deals with the physiology and genetics of glycolytic flux control in Zymomonas mobilis. Two fundamental biological questions are begin addressed: First, how do the enzymes of glycolytic pathways act in concert to regulate metabolic flux Second, what is the role of gene expression in regulating high level synthesis of the glycolytic enzymes in a balance that allows proper glycolytic flux control The specific objectives of the grant are as follows: 1. To clone the structural and regulatory regions of the Z. mobilis genes encoding glucose-6-phosphate dehydrogenase, phosphoglucose isomerase, enolase, 6-phosphogluconate dehydratase, 2- keto-3-deoxy- 6-phosphogluconate aldolase, glucokinase and fructokinase. 2. To characterize the structure of these genes with respect to nucleotide sequence, transcriptional initiation sites promoter location, evolutionary relatedness to similar genes from other organisms, and organization of these genes on the genome. 3. To investigate the effects of genetically engineered alterations in the levels of the cloned enzymes on metabolic flux and cell growth. 4. To study transcriptional and post-transcriptional regulation of the genes encoding the enzymes of the Entner-Doudoroff pathway. The first two specific objectives have now been fully completed. Significant progress has been made on the fourth objective and work on the third objective is well underway.
Date: January 1, 1992
Creator: Conway, T.
Partner: UNT Libraries Government Documents Department

Optimizing procedures for a human genome repository

Description: Large numbers of clones will be generated during the Human Genome Project. As each is characterized, subsets will be identified which are useful to the scientific community at large. These subsets are most readily distributed through public repositories. The American Type Culture Collection (ATCC) is experienced in repository operation, but before this project had no history in managing clones and associated information in large batches instead of individually. This project permitted the ATCC to develop several procedures for automating and thus reducing the cost of characterizing, preserving, and maintaining information about clones.
Date: March 1, 1991
Creator: Nierman, W.C.
Partner: UNT Libraries Government Documents Department

HIV envelope drift

Description: The consensus sequences for (HIV) the Human Immunodeficiency Virus,envelope proteins can also be examined with regard to what might be called differential drift. Conserved and hypervariable regions, or domains, of the envelope were defined in 1986, when the extent of conspicuous HIV variation began to be noticed. Although a large fraction of the envelope residues are subject to drift, once substition at some particular site begins, constraints will most likely naturally arise in relation to which residues will admit of substitution thereafater. Thus, we should not expect that the type 1 and type 2 HIVs will manifest identical patterns of conservation and hypervariability. They already reveal significant differences in the number of cysteine residues, for example; although it is far less obvious, there is some indication that with the sequences analyzed thus far that the Zairean and North American HIVs may be differentially drifting as a direct consequence of their high rates of diversification. What makes this case of drift so extraordinary is the rapid pace which appears to be characteristic of the HIV speciation, stemming from not merely the high mutation rate, but also from proliferation in what might be for these viruses a relatively new ecological niche. 3 figs.
Date: January 1, 1988
Creator: Myers, G.
Partner: UNT Libraries Government Documents Department

A national HIV (Human Immunodeficiency Virus) database that facilitates data sharing

Description: The purpose of this communication is to stimulate discussion on a National Human Immunodeficiency Virus (HIV) Database that facilitates and coordinates data sharing. We argue for the creation of a new database because significant gaps exists in the type of information that are available on HIV. Databases that extensively survey the published literature on HIV are widely available, however, databases that contain either raw data or that describe ongoing HIV research efforts are not widely available. For epidemiologists, sociologists and mathematical modelers, who need to draw on raw epidemiologic and behavior data from a broad range of fields, the existing databases are inadequate. In this paper we emphasize the particular requirements of epidemiologists, sociologists and modelers, and suggest a plan to accommodate their database needs.
Date: January 1, 1988
Creator: Layne, S.P.; Marr, T.G.; Stanley, E.A.; Hyman, J.M. & Colgate, S.A.
Partner: UNT Libraries Government Documents Department

Analyses of inter- and intra-patient variation in the V3 loop of the HIV-1 envelope protein

Description: The third hypervariable domain of the HIV-1 gp120 envelope protein (V3) has been the focus of intensive sequencing efforts. To date, nearly one thousand V3 loop sequences have been stored in the HIV sequence database. Studies have revealed that the V3 loop elicits potent type-specific immune responses, and that it plays a significant role in cell tropism and fusion . The immunogenic tip of the loop can serve as a type-specific neutralizing antibody epitope, as well as a cytotoxic T-cell epitope. A helper T-cell epitope that lies within the amino terminal half of the V3 loop has also been characterized. Despite the richness of the immunologic response to this region, its potential for variation makes it an elusive target for vaccine design. Analyses of sibling sequence sets (sets of viral sequences derived from one person) show that multiple forms of the immunogenic tip of the loop are found within most HIV-1 infected individuals. Viral V3 sequences obtained from epidemiologically unlinked individuals from North America and Europe show extensive variation. However, some amino acid positions distributed throughout the V3 loop are highly conserved, and there is also conservation of the charge class of amino acid able to occupy certain positions relative to the tip of the loop. By contrast, the sequences obtained from many countries throughout the African continent reveal that V3 is a remarkably fluid region with few absolute constraints on the nature of the amino acids that can occupy most positions in the loop. The high degree of heterogeneity in this region is particularly striking in view of its contribution to biologically important viral functions.
Date: September 17, 1991
Creator: Korber, B.; Myers, G. (Los Alamos National Lab., NM (United States)) & Wolinsky, S. (Northwestern Univ., Chicago, IL (United States). Medical School)
Partner: UNT Libraries Government Documents Department