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Articles 1 - 6 of 6
Full-Text Articles in Life Sciences
The Effect Of Water And Nitrogen On The Response Of Sorghum Cultivars With Contrasting Nitrogen Use Efficiency, Teshome Regassa
The Effect Of Water And Nitrogen On The Response Of Sorghum Cultivars With Contrasting Nitrogen Use Efficiency, Teshome Regassa
Teshome H. Regassa
Water and nitrogen (N) are important environmental factors limiting sorghum production. Information is lacking on the combined effects of water and N for cultivars with different degrees of water and/or N stress tolerance. Sorghum cultivars known for N and water stress tolerance difference were evaluated to identify plant characteristics contributing to N use efficiency (NUE). Cultivars San Chi San and CK-60 were evaluated at Mead, NE on a Sharpsburg silty clay loam soil under water (stress and non-stress), and N (0, 40, 80, and 120 kg ha−1) rates. Experimental units were arranged in split-split plot and treatments were …
Photoreactive Bicyclic Amino Acids As Substrates For Mutant Escherichia Coli Phenylalanyl-Trna Synthetases, Thomas Bentin, Ramin Hamzavi, Jahan Salomonsson, Hervé Roy, Michael Ibba, Peter E. Nielsen
Photoreactive Bicyclic Amino Acids As Substrates For Mutant Escherichia Coli Phenylalanyl-Trna Synthetases, Thomas Bentin, Ramin Hamzavi, Jahan Salomonsson, Hervé Roy, Michael Ibba, Peter E. Nielsen
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Unnatural amino acids carrying reactive groups that can be selectively activated under non-invasive biologically benign conditions are of interest in protein engineering as biological tools for the analysis of protein-protein and protein-nucleic acids interactions. The double ring system phenylalanine analogues benzofuranylalanine and benzotriazolylalanine were synthesized, and their photolability was tested by UV irradiation at 254, 320, and 365 nm. Although both showed photo reactivity, benzofuranylalanine appeared as the most promising compound because this amino acid was activated by UVA (long wavelength) irradiation. These amino acids were also tested for in vitro charging of tRNAPhe and for protein mutagenesis via …
Divergence In Non-Cognate Amino Acid Recognition Between Class I And Class Ii Lysyl-Trna Synthetases, Jeffrey D. Levengood, Sandro F. Ataide, Hervé Roy, Michael Ibba
Divergence In Non-Cognate Amino Acid Recognition Between Class I And Class Ii Lysyl-Trna Synthetases, Jeffrey D. Levengood, Sandro F. Ataide, Hervé Roy, Michael Ibba
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Lysine insertion during coded protein synthesis requires lysyl-tRNALys, which is synthesized by lysyl-tRNA synthetase (LysRS). Two unrelated forms of LysRS are known: LysRS2, which is found in eukaryotes, most bacteria, and a few archaea, and LysRS1, which is found in most archaea and a few bacteria. To compare amino acid recognition between the two forms of LysRS, the effects of l-lysine analogues on aminoacylation were investigated. Both enzymes showed stereospecificity toward the l-enantiomer of lysine and discriminated against noncognate amino acids with different R-groups (arginine, ornithine). Lysine analogues containing substitutions at other positions were generally most effective as …
Non-Inactivating Voltage-Gated Sodium Channels In Severe Myoclonic Epilepsy Of Infancy, T. H. Rhodes, Christoph Lossin, C. Vanoye, Alfred L. George
Non-Inactivating Voltage-Gated Sodium Channels In Severe Myoclonic Epilepsy Of Infancy, T. H. Rhodes, Christoph Lossin, C. Vanoye, Alfred L. George
Christoph Lossin, Ph.D.
Mutations in SCN1A, the gene encoding the brain voltage-gated sodium channel alpha(1) subunit (Na(V)1.1), are associated with at least two forms of epilepsy, generalized epilepsy with febrile seizures plus and severe myoclonic epilepsy of infancy (SMEI). We examined the functional properties of five SMEI mutations by using whole-cell patch-clamp analysis of heterologously expressed recombinant human SCN1A. Two mutations (F902C and G1674R) rendered SCN1A channels nonfunctional, and a third allele (G1749E) exhibited minimal functional alterations. However, two mutations within or near the S4 segment of the fourth repeat domain (R1648C and F1661S) conferred significant impairments in fast inactivation, including persistent, noninactivating …
Changes In Gdnf Protein Content Of Skeletal Muscle Following Involuntary Exercise Are Long Lived, Kyle R. Kinnell, Monica J. Czarnopys, John Spitsbergen
Changes In Gdnf Protein Content Of Skeletal Muscle Following Involuntary Exercise Are Long Lived, Kyle R. Kinnell, Monica J. Czarnopys, John Spitsbergen
Biological Sciences Faculty and Graduate Student Research
Glial-cell line derived neurotrophic factor (GDNF) is a neurotrophic factor produced by skeletal muscle. GDNF has been shown to be potent survival factor for motor neurons. We have previously shown that GDNF content in skeletal muscle is altered following exercise and GDNF levels 24 hours after the last bout of exercise are significantly different than those measured immediately after exercise. We sought to determine how long after exercise do GDNF protein levels remain altered. We removed extensor digitorum longus (EDL) and Soleus (SOL), 24 hr, 72 hr and 1 week following the last bout of involuntary exercise. Muscles were processed …
Aminoacyl-Trnas: Setting The Limits Of The Genetic Code, Michael Ibba, Dieter Söll
Aminoacyl-Trnas: Setting The Limits Of The Genetic Code, Michael Ibba, Dieter Söll
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Aminoacyl-tRNAs (aa-tRNAs) are simple molecules with a single purpose—to serve as substrates for translation. They consist of mature tRNAs to which an amino acid has been esterified at the 3′-end. The 20 different types of aa-tRNA are made by the 20 different aminoacyl-tRNA synthetases (aaRSs, of which there are two classes), one for each amino acid of the genetic code (Ibba and Söll 2000). This would be fine if it were not for the fact that such a straightforward textbook scenario is not true in a single known living organism. aa-tRNAs lie at the heart of gene expression; they interpret …