Open Access. Powered by Scholars. Published by Universities.®

Biochemistry, Biophysics, and Structural Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 9 of 9

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

The Rna-Binding Site Of Bacteriophage Qβ Coat Protein, Francis Lim, Marc Spingola, David S. Peabody Dec 1996

The Rna-Binding Site Of Bacteriophage Qβ Coat Protein, Francis Lim, Marc Spingola, David S. Peabody

Marc Spingola

The coat proteins of the RNA bacteriophages Qβ and MS2 are specific RNA binding proteins. Although they possess common tertiary structures, they bind different RNA stem loops and thus provide useful models of specific protein-RNA recognition. Although the RNA-binding site of MS2 coat protein has been extensively characterized previously, little is known about Qβ. Here we describe the isolation of mutants that define the RNA-binding site of Qβ coat protein, showing that, as with MS2, it resides on the surface of a large β-sheet. Mutations are also described that convert Qβ coat protein to the RNA binding specificity of MS2. …


Oxidized Low Density Lipoprotein And Lysophosphatidylcholine Stimulate Cell Cycle Entry In Vascular Smooth Muscle Cells - Evidence For Release Of Fibroblast Growth Factor-2., Yuh-Cherng Chai, Philip Howe, Paul Dicorletto, Guy Chisolm Jul 1996

Oxidized Low Density Lipoprotein And Lysophosphatidylcholine Stimulate Cell Cycle Entry In Vascular Smooth Muscle Cells - Evidence For Release Of Fibroblast Growth Factor-2., Yuh-Cherng Chai, Philip Howe, Paul Dicorletto, Guy Chisolm

Yuh-Cherng Chai

We have previously shown that oxidized low density lipoprotein (LDL) but not native LDL stimulated DNA synthesis in cultured smooth muscle cells (SMC) and that α-tocopherol (vitamin E) inhibited this proliferative response (Lafont, A., Chai, Y. C., Cornhill, J. F., Whitlow, P. L., Howe, P. H., and Chisolm, G. M. (1995) J. Clin. Invest. 95, 1018-1025). The moiety of oxidized LDL that stimulates DNA synthesis and the cellular mechanism for this potentially mitogenic effect are not known. We now report that lipid fractions containing lysophospholipids from oxidized LDL or phospholipase A2-treated native LDL stimulated SMC DNA synthesis as did palmitoyl …


Developmental And Tissue-Specific Expression Of Mouse Pelle-Like Protein Kinase, Marina Trofimova, Amy B. Sprenkle, Melissa Green, Thomas W. Sturgill, Mark G. Goebl, Maureen A. Harrington Jul 1996

Developmental And Tissue-Specific Expression Of Mouse Pelle-Like Protein Kinase, Marina Trofimova, Amy B. Sprenkle, Melissa Green, Thomas W. Sturgill, Mark G. Goebl, Maureen A. Harrington

Amy Sprenkle

The NF-kappaB/c-Rel proteins are a family of evolutionarily conserved transcription factors activated during development that in the adult, mediate many processes including the immune response. A high degree of sequence similarity is shared between the NF-kappaB/c-Rel family of transcription factors and the Drosophila Dorsal protein as well as between its cytoplasmic inhibitor, IkappaBalpha, and the Drosophila Cactus protein. Genetic analyses of Dorsal have defined components of a signaling pathway for Dorsal activation, including a serine/threonine kinase, Pelle, placed upstream of Dorsal and Cactus. We demonstrate that this pathway is likely to be conserved in mammals by the isolation of a …


Degradation Studies Of The Non-Lethal Bird Repellent, Methyl Anthranilate, Eugeny Aronov, Larry Clark Jan 1996

Degradation Studies Of The Non-Lethal Bird Repellent, Methyl Anthranilate, Eugeny Aronov, Larry Clark

Larry Clark

Methyl anthranilate (MA), a food grade flavor and fragrance additive, has been reported to be an effective non-lethal bird repellent in a variety of situations. Despite the experimental success of MA, field studies have yielded widely differing levels of efficacy. Diminished efficacy in some field trials prob­ ably results from the failure of specific formulations to retain or protect the active ingredient under natural conditions. Therefore, a clearer understanding of the physical and chemical factors affecting the stability of MA is needed. We undertook a series of laboratory studies on hydrolysis, photolysis and microbial degradation of MA, the results of …


Development Of An Enzyme-Linked Immunosorbent Assay (Elisa) For Quantification Of Skeletal Muscle Calpastatin, M. E. Doumit, Steven M. Lonergan, J. R. Arbona, J. Killefer, M. Koohmaraie Jan 1996

Development Of An Enzyme-Linked Immunosorbent Assay (Elisa) For Quantification Of Skeletal Muscle Calpastatin, M. E. Doumit, Steven M. Lonergan, J. R. Arbona, J. Killefer, M. Koohmaraie

Steven M. Lonergan

An indirect antibody ELISA was developed for rapid and sensitive quantification of skeletal muscle calpastatin. Polyclonal antibodies were raised in rabbits against recombinant calpastatin, corresponding to domains 2, 3, and 4 of bovine skeletal muscle calpastatin. Western blot analysis revealed that these antibodies specifically recognize an immunoreactive calpastatin protein of approximately 130 kDa in prerigor skeletal muscle extracts. The intensity of the immunoreactive bands corresponds qualitatively with assayable calpastatin activity. For ELISA development, optimum dilutions of sample, primary anti-calpastatin antibody, and peroxidase-conjugated secondary antibody were determined by titration. A dilution optimum for coating of Immulonâ 4 (Dynatech) plates was observed …


Effects Of The Ferritin Open Reading Frame On Translational Induction By Iron., David Mascotti, Lisa Goessling, Diane Rup, Robert Thach Dec 1995

Effects Of The Ferritin Open Reading Frame On Translational Induction By Iron., David Mascotti, Lisa Goessling, Diane Rup, Robert Thach

David P. Mascotti

No abstract provided.


In-Situ Imaging Of Ionic Crystal Dissolution Using An Integrated Electrochemical/Afm Probe, Julie V. Macpherson, Patrick R. Unwin, Andrew C. Hillier, Allen J. Bard Dec 1995

In-Situ Imaging Of Ionic Crystal Dissolution Using An Integrated Electrochemical/Afm Probe, Julie V. Macpherson, Patrick R. Unwin, Andrew C. Hillier, Allen J. Bard

Andrew C. Hillier

The kinetics and mechanism controlling dissolution from the (100) cleavage face of potassium bromide single crystals in acetonitrile solutions have been identified using a novel integrated electrochemical/AFM probe and a scanning electrochemical microscope (SECM). With both techniques, dissolution is induced by perturbing the dynamic dissolution/growth equilibrium at the crystal/solution interface through the electrochemical oxidation of bromide ions. SECM measurements demonstrate that the dissolution reaction is diffusion-limited under the experimental conditions, suggesting that the surface reaction is characterized by a rate constant in excess of 5 cm s-1 (assuming a first-order dissolution process). The topography of the dissolving surface has been …


Measurement Of Double-Layer Forces At The Electrode/Electrolyte Interface Using The Atomic Force Microscope: Potential And Anion Dependent Interactions, Andrew C. Hillier, Sunghyun Kim, Allen J. Bard Dec 1995

Measurement Of Double-Layer Forces At The Electrode/Electrolyte Interface Using The Atomic Force Microscope: Potential And Anion Dependent Interactions, Andrew C. Hillier, Sunghyun Kim, Allen J. Bard

Andrew C. Hillier

The forces between a silica probe and silica and gold substrates were measured with an atomic force microscope in the presence of a series of alkali-halide electrolyte solutions. The interaction between two silica surfaces was repulsive and could be accurately predicted by Derjaguin-Landau-Verwey-Overbeek theory. The silica surface was negatively charged at a pH of 5.5 and the effective surface potential increased in magnitude with decreasing electrolyte concentration. In contrast, the force between the silica probe and a gold substrate was attractive at open circuit. This interaction was a strong function of the potential applied to the gold and the nature …


The Chlorophyll Biosynthetic Enzyme Mg-Protoporphyrin Ix Monomethyl Ester (Oxidative) Cyclase (Characterization And Partial Purification From Chlamydomonas Reinhardtii And Synechocystis Sp. Pcc 6803), David Bollivar Dec 1995

The Chlorophyll Biosynthetic Enzyme Mg-Protoporphyrin Ix Monomethyl Ester (Oxidative) Cyclase (Characterization And Partial Purification From Chlamydomonas Reinhardtii And Synechocystis Sp. Pcc 6803), David Bollivar

David Bollivar

A universal structural feature of chlorophyll molecules is the isocyclic ring. This ring is formed by the action of the enzyme Mg-protoporphyrin IX monomethyl ester (oxidative) cyclase, which catalyzes a complex reaction in which Mg-protoporphyrin IX monomethyl ester is converted to divinyl protochlorophyllide (also called Mg-2,4-divinylpheoporphyrin a5), with the participation of NADPH and O2. Cyclase activity was demonstrated in lysed Chlamydomonas reinhardtii chloroplasts and extracts of Synechocystis sp. PCC 6803. The yield of the reaction product was increased by the addition of catalase and ascorbate or isoascorbate to the incubation mixture. These compounds may act by preventing degradation of the …