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Site Directed Mutagenesis Of Dienelactone Hydrolase

Description: The role of individual amino acid residues of the enzyme dienelactone hydrolase was investigated. Using the polymerase chain reaction (PCR), a 1.9 kbp clcD fragment was amplified and subcloned yielding a 821 bp BamHI to EcoRI clcD subclone in the plasmid pUC19. Site-specific mutants of dienelactone hydrolase were created using mismatched oligonucleotides to prime DNA synthesis. Specifically modified proteins from mutated clcD genes (Arg 81 to alanine, Tyr 85 to phenylalanine and Arg 206 to alanine), were encoded by the mutant clones. Enzyme assays showed that dienelactone hydrolase activity of the mutants Arg 81 and Arg 206 was totally abolished. The DLHase enzyme activity of mutant Tyr 85 is greatly decreased by approximately two thirds.
Date: December 1992
Creator: Chen, Wei, 1965-
Partner: UNT Libraries

Site Directed Mutagenesis of β-Ketoadipate Succinyl-Coenzyme A Transferase II from Acinetobacter Calcoaceticus

Description: The role of specific amino acid residues in β-ketoadipate succinyl-coenzyme A transferase II from Acinetobacter calcoaceticus was investigated. A 1412 base pair BamiHI-EcoRI fragment carrying the catIJ genes was amplified by polymerase chain reaction and inserted into pUCl9 to generate the plasmid pCATEl9. Escherichia coli DH5α (pCATEl9) carrying only the catlJ genes expressed 3-fold higher enzyme activity than the parent strain. Two mutants were constructed by site directed mutagenesis so that glutamate was replaced by a glutamine at positions Gln155 and Gln193 in the ß subunit of the primary amino acid sequence of the CoA transferase. Both mutants produced transferase that was catalytically active suggesting that Glu155 and Glu193 do not participate directly in catalysis.
Date: August 1993
Creator: Sheng, Mei
Partner: UNT Libraries

Teratogenic and Mutagenic Potential of Triethylenemelamine, Ethyl Methanesulfonate, and N-Ethyl-N-Nitrosourea for Causing Fetal Anomalies in Mus Musculus

Description: In five separate experiments, weight-adjusted doses of TEM, EMS, and ENU were injected intraperitoneally into twelve week-old female mice six hours after mating. On day seventeen of gestation, the females were sacrificed and their uterine contents were examined. The effect of each agent was determined by its ability to cause malformations and death to the developing embryos. All treatment groups showed statistically significant elevated levels of malformations in comparison to their corresponding control groups. The reproductive damage induced in these experiments cannot be singularly attributed to teratogenesis or mutagenesis but a combination of the two.
Date: December 1987
Creator: Gans, Murry J. (Murry Joe)
Partner: UNT Libraries

Meeting Report. Assessing Human Germ-Cell Mutagenesis in thePost-Genome Era: A Celebration of the Legacy of William Lawson (Bill)Russell

Description: Although numerous germ-cell mutagens have been identified inanimal model systems, to date, no human germ-cell mutagens have beenconfirmed. Because the genomic integrity of our germ cells is essentialfor the continuation of the human species, a resolution of this enduringconundrum is needed. To facilitate such a resolution, we organized aworkshop at The Jackson Laboratory in Bar Harbor, Maine on September28-30, 2004. This interactive workshop brought together scientists from awide range of disciplines to assess the applicability of emergingmolecular methods for genomic analysis to the field of human germ-cellmutagenesis. Participants recommended that focused, coordinated humangerm-cell mutation studies be conducted in relation to important societalexposures. Because cancer survivors represent a unique cohort withwell-defined exposures, there was a consensus that studies should bedesigned to assess the mutational impact on children born to parents whohad received certain types of mutagenic cancer chemotherapy prior toconceiving their children. Within this high-risk cohort, parents andchildren could be evaluated for inherited changes in (a) gene sequencesand chromosomal structure, (b) repeat sequences and minisatelliteregions, and (c) global gene expression and chromatin. Participants alsorecommended studies to examine trans-generational effects in humansinvolving mechanisms such as changes in imprinting and methylationpatterns, expansion of nucleotide repeats, or induction of mitochondrialDNA mutations. Workshop participants advocated establishment of abio-bank of human tissue samples that could be used to conduct amultiple-endpoint, comprehensive, and collaborative effort to detectexposure-induced heritable alterations in the human genome. Appropriateanimal models of human germ-cell mutagenes is should be used in parallelwith human studies to provide insights into the mechanisms of mammaliangerm-cell mutagenesis. Finally, participants recommended that scientificspecialty groups be convened to address specific questions regarding thepotential germ-cell mutagenicity of environmental, occupational, andlifestyle exposures. Strong support from relevant funding agencies andengagement of scientists outside the fields of genomics and germ-cellmutagenesis will be required to launch a full-scale assault on some ofthe most pressing and ...
Date: April 18, 2006
Creator: Wyrobek, Andrew J.; Mulvihill, John J.; Wassom, John S.; Malling,Heinrich V.; Shelby, Michael D.; Lewis, Susan E. et al.
Partner: UNT Libraries Government Documents Department

The BDGP gene disruption project: Single transposon insertions associated with 40 percent of Drosophila genes

Description: The Berkeley Drosophila Genome Project (BDGP) strives to disrupt each Drosophila gene by the insertion of a single transposable element. As part of this effort, transposons in more than 30,000 fly strains were localized and analyzed relative to predicted Drosophila gene structures. Approximately 6,300 lines that maximize genomic coverage were selected to be sent to the Bloomington Stock Center for public distribution, bringing the size of the BDGP gene disruption collection to 7,140 lines. It now includes individual lines predicted to disrupt 5,362 of the 13,666 currently annotated Drosophila genes (39 percent). Other lines contain an insertion at least 2 kb from others in the collection and likely mutate additional incompletely annotated or uncharacterized genes and chromosomal regulatory elements. The remaining strains contain insertions likely to disrupt alternative gene promoters or to allow gene mis-expression. The expanded BDGP gene disruption collection provides a public resource that will facilitate the application of Drosophila genetics to diverse biological problems. Finally, the project reveals new insight into how transposons interact with a eukaryotic genome and helps define optimal strategies for using insertional mutagenesis as a genomic tool.
Date: January 13, 2004
Creator: Bellen, Hugo J.; Levis, Robert W.; Liao, Guochun; He, Yuchun; Carlson, Joseph W.; Tsang, Garson et al.
Partner: UNT Libraries Government Documents Department

Homology with vesicle fusion mediator syntaxin-1a predicts determinants ofepimorphin/syntaxin-2 function in mammary epithelial morphogenesis

Description: We have shown that branching morphogenesis of mammary ductal structures requires the action of the morphogen epimorphin/syntaxin-2. Epimorphin, originally identified as an extracellular molecule, is identical to syntaxin-2, an intracellular molecule that is a member of the extensively investigated syntaxin family of proteins that mediate vesicle trafficking. We show here that although epimorphin/syntaxin-2 is highly homologous to syntaxin-1a, only epimorphin/syntaxin-2 can stimulate mammary branching morphogenesis. We construct a homology model of epimorphin/syntaxin-2 based on the published structure of syntaxin-1a, and we use this model to identify the structural motif responsible for the morphogenic activity. We identify four residues located within the cleft between helices B and C that differ between syntaxin-1a and epimorphin/syntaxin-2; through site-directed mutagenesis of these four amino acids, we confer the properties of epimorphin for cell adhesion, gene activation, and branching morphogenesis onto the inactive syntaxin-1a template. These results provide a dramatic demonstration of the use of structural information about one molecule to define a functional motif of a second molecule that is related at the sequence level but highly divergent functionally.
Date: June 3, 2009
Creator: Chen, Connie S.; Nelson, Celeste M.; Khauv, Davitte; Bennett, Simone; Radisky, Evette S.; Hirai, Yohei et al.
Partner: UNT Libraries Government Documents Department

A Novel Mechanism for Site-Directed Mutagenesis of Large Catabolic Plasmids Using Natural Transformation

Description: Natural transformation is the process by which cells take up DNA from the surrounding medium under physiological conditions, altering the genotype in a heritable fashion. This occurs without chemical or physical treatment of the cells. Certain Acinetobacter strains exhibit a strong tendency to incorporate homologous DNA into their chromosomes by natural transformation. Transformation in Acinetobacter exhibits several unique properties that indicate this system's superiority as a model for transformation studies or studies which benefit from the use of transformation as an experimental method of gene manipulation. Pseudomonas putida is the natural host of TOL plasmids, ranging between 50 kbp and 300 kbp in size and encoding genes for the catabolism of toluene, meta-toluate, and xylene. These very large, single-copy plasmids are difficult to isolate, manipulate, or modify in vitro. In this study, the TOL plasmid pDKR1 was introduced into Acinetobacter calcoaceticus strains and genetically engineered utilizing natural transformation as part of the process. Following engineering by transformation, the recombinant DNA molecule was returned to the native genetic background of the original host P. putida strain. Specific parameters for the successful manipulation of large plasmids by natural transformation in Acinetobacter were identified and are outlined. The effects of growth phase, total transforming DNA concentration, transforming DNA conformation, and gene dosage on transformation efficiency are presented. Addition of Acinetobacter plasmid DNA sequences to the manipulated constructs did not have an effect on transformation rates. Results suggest that a broadly applicable and efficient method to carry out site-directed genetic manipulations of large plasmids has been identified. The ability to easily reintroduce the recombinant DNA molecules back into the original host organism was maintained.
Date: August 2001
Creator: Williamson, Phillip C.
Partner: UNT Libraries

Discovery and Characterization of Two Tn5 Generated pyrA Mutants in Pseudomonas putida and the Generation of Hfr Strains

Description: A pyrA mutation in Pseudomonas putida was isolated using transposon mutagenesis for the first time. Transposon Tn5 was used to inactivate the pyrA gene for carbamoylphosphate synthetase in these mutants. Accordingly, these mutants were defective in pyrimidine and arginine biosynthesis. The suicide vector, pM075, from Pseudomonas aeruginosa, was used to introduce the transposon into the cells. Tn5 was subsequently used to supply homology so that the plasmid pM075 could be introduced in its entirety into the Pseudomonas putida chromosome at the locus of the Tn5 insertion in the pyrA gene. Consequently, these strains exhibited high frequency of recombination and were capable of chromosome mobilization.
Date: August 1994
Creator: Liljestrand, Laura Gail
Partner: UNT Libraries

Site Directed Mutagenesis of Dienelactone Hydrolase

Description: The clcD gene encoding dienelactone hydrolase (DLH) is part of the clc gene cluster for the utilization of the B-ketoadipate pathway intermediate chlorocatechol. The roles that individual amino acids residues play in catalysis and binding of the enzyme were investigated. Using PCR a 1.9 kbp clcD fragment was amplified and subcloned yielding a 821 bp BamHi to ZscoRI subclone in the plasmid pUC19.
Date: August 1995
Creator: Al-Khatib, Haifa Yousef
Partner: UNT Libraries

Miscoding properties of 1,N{sup 6}-ethanoadenine, a DNA adduct derived from reaction with antitumor agent 1,3-bis(2-chloroethyl)-1-nitrosourea

Description: 1,N{sup 6}-Ethanoadenine (EA) is an exocyclic adduct formed from DNA reaction with the antitumor agent, 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). To understand the role of this adduct in the mechanism of mutagenicity or carcinogenicity by BCNU, an oligonucleotide with a site-specific EA was synthesized using phosphoramidite chemistry. We now report the in vitro miscoding properties of EA in translesion DNA synthesis catalyzed by mammalian DNA polymerases (pols) {alpha}, {beta}, {eta} and {iota}. These data were also compared with those obtained for the structurally related exocyclic adduct, 1,N{sup 6}-ethenoadenine ({var_epsilon}A). Using a primer extension assay, both pols {alpha} and {beta} were primarily blocked by EA or {var_epsilon}A with very minor extension. Pol {eta} a member of the Y family of polymerases, was capable of catalyzing a significant amount of bypass across both adducts. Pol {eta} incorporated all four nucleotides opposite EA and {var_epsilon}A, but with differential preferences and mainly in an error-prone manner. Human pol {iota}, a paralog of human pol {eta}, was blocked by both adducts with a very small amount of synthesis past {var_epsilon}A. It incorporated C and, to a much lesser extent, T, opposite either adduct. In addition, the presence of an A adduct, e.g. {var_epsilon}A, could affect the specificity of pol {iota} toward the template T immediately 3 feet to the adduct. In conclusion, the four polymerases assayed on templates containing an EA or {var_epsilon}A showed differential bypass capacity and nucleotide incorporation specificity, with the two adducts not completely identical in influencing these properties. Although there was a measurable extent of error-free nucleotide incorporation, all these polymerases primarily misincorporated opposite EA, indicating that the adduct, similar to {var_epsilon}A, is a miscoding lesion.
Date: March 5, 2003
Creator: Hang, Bo; Guliaev, Anton B.; Chenna, Ahmed & Singer, B.
Partner: UNT Libraries Government Documents Department

The Laminin 511/521 Binding Site on the Lutheran Blood Group Glycoprotein is Located at theFlexible Junction of Ig Domains 2 and 3

Description: The Lutheran blood group glycoprotein, first discovered on erythrocytes, is widely expressed in human tissues. It is a ligand for the {alpha}5 subunit of Laminin 511/521, an extracellular matrix protein. This interaction may contribute to vasocclusive events that are an important cause of morbidity in sickle cell disease. Using X-ray crystallography, small angle X-ray scattering and site directed mutagenesis we show that the extracellular region of Lutheran forms an extended structure with a distinctive bend between the second and third immunoglobulin-like domains. The linker between domains 2 and 3 appears to be flexible and is a critical determinant in maintaining an overall conformation for Lutheran that is capable of binding to Laminin. Mutagenesis studies indicate that Asp312 of Lutheran and the surrounding cluster of negatively charged residues in this linker region form the Laminin binding site. Unusually, receptor binding is therefore not a function of the domains expected to be furthermost from the plasma membrane. These studies imply that structural flexibility of Lutheran may be essential for its interaction with Laminin and present a novel opportunity for the development of therapeutics for sickle cell disease.
Date: July 1, 2007
Creator: Mankelow, Tosti J.; Burton, Nicholas; Stedansdottir, Fanney O.; Spring, Frances A.; Parsons, Stephen F.; Pesersen, Jan S. et al.
Partner: UNT Libraries Government Documents Department

A New Selectable Marker System for Genetic Studies of Bacteria: Final Report

Description: Genetic manipulations in bacteria currently rely on the introduction of antibiotic resistance genes into a bacterial strain; for those organisms that will be used for commercial or industrial applications, the genetic cassette encoding the antibiotic resistance is sometimes removed after selection. it is clear that if alternative technologies could obviate the need to introduce antibiotic resistance into bacteria, they would most certainly become a standard tool in molecular micriobiology for commercial, industrial as well as research applications. Here, they present the development of a novel genetic engineering technology based on toxin-antitoxin systems to modify bacterial genomes without the use of antibiotic resistance in the mutagenesis process. The primary goal is to develop antibiotic-free selection for genetically altered select agent pathogens. They are adapting the toxinc-antitoxin system to enable gene replacement in select agent pathogens since the NIH restrictions introducing antibiotic resistance into select agent pathogens have hindered research with select agent pathogens.
Date: March 18, 2011
Creator: Parsons, D; Tolmasky, M; Chain, P & Segelke, B W
Partner: UNT Libraries Government Documents Department

A NON-CLEAVABLE UmuD VARIANT THAT ACTS AS A UmuD' MIMIC

Description: UmuD{sub 2} cleaves and removes its N-terminal 24 amino acids to form UmuD'{sub 2}, which activates UmuC for its role in UV-induced mutagenesis in E. coli. Cells with a non-cleavable UmuD exhibit essentially no UV-induced mutagenesis and are hypersensitive to killing by UV light. UmuD has been shown to bind to the beta processivity clamp (''beta'') of the replicative DNA polymerase, pol III. A possible beta-binding motif has been predicted in the same region of UmuD shown to be important for its interaction with beta. We performed alanine-scanning mutagenesis of this motif (14-TFPLF-18) in UmuD and showed that it has a moderate influence on UV-induced mutagenesis but is required for the cold sensitive phenotype caused by elevated levels of wild-type UmuD and UmuC. Surprisingly, the wild-type and the beta-binding motif variant bind to beta with similar K{sub d} values as determined by changes in tryptophan fluorescence. However, this data also implies that the single tryptophan in beta is in strikingly different environments in the presence of the wild-type versus the variant UmuD proteins, suggesting a distinct change in some aspect of the interaction with little change in its strength. Despite the fact that this novel UmuD variant is noncleavable, we find that cells harboring it exhibit phenotypes more consistent with the cleaved form UmuD', such as resistance to killing by UV light and failure to exhibit the cold sensitive phenotype. Cross-linking and chemical modification experiments indicate that the N-terminal arms of the UmuD variant are less likely to be bound to the globular domain than those of the wild-type, which may be the mechanism by which this UmuD variant acts as a UmuD' mimic.
Date: October 26, 2005
Creator: Beuning, P J; Simon, S M; Zemla, A; Barsky, D & Walker, G C
Partner: UNT Libraries Government Documents Department

Mutagenic Potency of Food-Derived Heterocyclic Amines

Description: The understanding of mutagenic potency has been primarily approached using ''quantitative structure activity relationships'' (QSAR). Often this method allows the prediction of mutagenic potency of the compound based on its structure. But it does not give the underlying reason why the mutagenic activities differ. We have taken a set of heterocyclic amine structures and used molecular dynamic calculations to dock these molecules into the active site of a computational model of the cytochrome P-450 1A1 enzyme. The calculated binding strength using Boltzman distribution constants was then compared to the QSAR value (HF/6-31G* optimized structures) and the Ames/Salmonella mutagenic potency. Further understanding will only come from knowing the complete set of mutagenic determinants. These include the nitrenium ion half-life, DNA adduct half-life, efficiency of repair of the adduct, and ultimately fixation of the mutation through cellular processes. For two isomers, PhIP and 3-Me-PhIP, we showed that for the 100-fold difference in the mutagenic potency a 5-fold difference can be accounted for by differences in the P450 oxidation. The other factor of 20 is not clearly understood but is downstream from the oxidation step. The application of QSAR (chemical characteristics) to biological principles related to mutagenesis is explored in this report.
Date: October 26, 2006
Creator: Felton, J S; Knize, M G; Wu, R W; Colvin, M E; Hatch, F T & Malfatti, M A
Partner: UNT Libraries Government Documents Department

Analysis of a Ferric Uptake Regulator (Fur) Mutant ofDesulfovibrio vulgaris Hildenborough

Description: Previous experiments examining the transcriptional profileof the anaerobe Desulfovibrio vulgaris demonstrated up-regulation of theFur regulon in response to various environmental stressors. To test theinvolvement of Fur in the growth response and transcriptional regulationof D. vulgaris, a targeted mutagenesis procedure was used for deletingthe fur gene. Growth of the resulting ?fur mutant (JW707) was notaffected by iron availability, but the mutant did exhibit increasedsensitivity to nitrite and osmotic stresses compared to the wild type.Transcriptional profiling of JW707 indicated that iron-bound Fur acts asa traditional repressor for ferrous iron uptake genes (feoAB) and othergenes containing a predicted Fur binding site within their promoter.Despite the apparent lack of siderophore biosynthesis genes within the D.vulgaris genome, a large 12-gene operon encoding orthologs to TonB andTolQR also appeared to be repressed by iron-bound Fur. While other genespredicted to be involved in iron homeostasis were unaffected by thepresence or absence of Fur, alternative expression patterns that could beinterpreted as repression or activation by iron-free Fur were observed.Both the physiological and transcriptional data implicate a globalregulatory role for Fur in the sulfate-reducing bacterium D.vulgaris.
Date: September 21, 2007
Creator: Bender, Kelly S.; Yen, Huei-Che Bill; Hemme, Christopher L.; Yang, Zamin K.; He, Zhili; He, Qiang et al.
Partner: UNT Libraries Government Documents Department

Rb and p53 gene deletions in lung adenocarcinomas from irradiated and control mice

Description: This study was conducted on mouse lung adenocarcinoma tissues that were formalin-treated and paraffin-embedded 25 years ago to investigate the large gene deletions of mRb and p53 in B6CF{sub 1} male mice. A total of 80 lung tissue samples from irradiated mice and 40 lung samples from nonirradiated controls were randomly selected and examined in the mRb portion of this study. The results showed a significant (P < 0.05) higher percentage of mRb deletions in lung adenocarcinomas from mice exposed to 60 once-weekly {gamma}-ray doses than those from mice receiving 24 once-weekly {gamma}-ray doses at low doses and low dose rates; however, the percentage was not significantly different (P > 0.05) from that for spontaneous lung adenocarcinomas or lung adenocarcinomas from mice exposed to single-dose {gamma} irradiation at a similar total dose. mRb fragments 3 (71%) and 5 (67%), the parts of the gene that encoded the pocket binding region of Rb protein to adenovirus E1A and SV40 T-antigen, were the most frequently deleted fragments. p53 gene deletion analysis was carried out on normal lungs and lung adenocarcinomas that were initially found to bear mRb deletions. Exons 1,4,5,6, and 9 were chosen to be analyzed.
Date: August 1, 1997
Creator: Zhang, Y. & Woloschak, G.E.
Partner: UNT Libraries Government Documents Department

In-Situ Survival Mechanisms of U and Tc Reducing Bacteria in Contaminated Sediments Final Report

Description: The proposed effort will identify genes and ultimately physiological mechanisms and pathways that are expressed under in situ conditions and are critical to functioning of aquifer dwelling anaerobic bacteria living in contaminated systems. The main objectives are: (1) Determine which Metal-reducer specific genes are important for activities in normal and contaminated subsurface sediment. To achieve these goals, we have generated a library of chromosomal mutants. These are introduced into contaminated sediments, incubated, allowed to grow, and then reisolated. A negative selection process allows us to determine which mutants have been selected against in sediments and thereby identify genes required for survival in subsurface sediments. (2) Delineate the function of these genes through GeneBank and Clusters of Orthologous Groups (COGs) comparisons and analyze other sediment microorganisms to determine if similar genes are present in these populations. After determining the sequence of the genes identified through the previous objectives, we delineate the role of those specific genes in the physiology of G20, MR-1 and perhaps other microorganisms. (3) Determine the loss in function of a select group of mutants. Cells with mutations in known genes with testable functions are assayed for the loss of that function if specific assays are available. Mutants with unknown loss of function and other mutants are run through a series of tests including motility, attachment, and rate of sulfate or iron reduction. These tests allow us to categorize mutants for subsequent more detailed study.
Date: July 11, 2005
Creator: Krumholz, Lee R. & Ballard, Jimmy D.
Partner: UNT Libraries Government Documents Department

Metabolic Design and Control for Production in Prokaryotes

Description: Prokaryotic life on earth is manifested by its diversity and omnipresence. These microbes serve as natural sources of a large variety of compounds with the potential to serve the ever growing, medicinal, chemical and transportation needs of the human population. However, commercially viable production of these compounds can be realized only through significant improvement of the native production capacity of natural isolates. The most favorable way to achieve this goal is through the genetic manipulation of metabolic pathways that direct the production of these molecules. While random mutagenesis and screening have dominated the industrial production of such compounds in the past our increased understanding of microbial physiology over the last five decades has shifted this trend towards rational approaches for metabolic design. Major drivers of this trend include recombinant DNA technology, high throughput characterization of macromolecular cellular components, quantitative modeling for metabolic engine ring, targeted combinatorial engineering and synthetic biology. In this chapter we track the evolution of microbial engineering technologies from the black box era of random mutagenesis to the science and engineering-driven era of metabolic design.
Date: November 10, 2010
Creator: Chhabra, Swapnil R. & Keasling, J.D.
Partner: UNT Libraries Government Documents Department

Biosynthesis of the Cyclotide MCoTI-II using an Engineered Intein

Description: Cyclotides are an emerging family of naturally occurring circular mini-proteins ({approx}30-40 amino acids) characterized by six conserved Cys residues (forming 3 disulfide bridges) that create a topologically unique structure designated as a cyclic cysteine knot (CCK). The cysteine knot motif, which is embedded within the macrocylic backbone, is described as two disulfide bridges that form a ring that is penetrated by the third disulfide bridge. The cyclic backbone and CCK motif together confer cyclotides with a remarkable stability and resistance to proteolytic, chemical, and thermal degradation. Further, cyclotides are functionally diverse and display a wide range of functions including uterotonic activity, trypsin inhibition, cytotoxicity, neurotensin binding, anti-HIV, antimicrobial, and insecticidal activity. Together, these characteristics make cyclotides attractive candidates for both drug design and agricultural applications, both in their native forms and as molecular scaffolds for the incorporation of novel bioactivities. [1] The ability to manipulate production of cyclotides within biological systems is critical for mutagenesis studies, production of grafted products, and the mass production of cyclotides with novel activities. My adviser's hope is to achieve this capability by employing recombinant DNA expression techniques to generate large combinatorial libraries of cyclotides. The advantage in creating a biosynthetic library (containing {approx}10{sup 6}-10{sup 10} members/library vs. chemically based libraries with typical values ranging from {approx}10{sup 3}-10{sup 5} members/library) is that it can be lead to the in vivo application of biological screening and selection methodologies based on a specific clone's ability to affect certain cellular processes.
Date: August 15, 2006
Creator: Cantor, J & Camarero, J A
Partner: UNT Libraries Government Documents Department