Biochemistry Commons^™

A Bulk Water-Dependent Desolvation Energy Model For Analyzing The Effects Of Secondary Solutes On Biological Equilibria, Daryl K. Eggers

Faculty Publications, Chemistry

A new phenomenological model for interpreting the effects of solutes on biological equilibria is presented. The model attributes changes in equilibria to differences in the desolvation energy of the reacting species that, in turn, reflect changes in the free energy of the bulk water upon addition of secondary solutes. The desolvation approach differs notably from that of other solute models by treating the free energy of bulk water as a variable and by not ascribing the observed shifts in reaction equilibria to accumulation or depletion of solutes next to the surfaces of the reacting species. On the contrary, the partitioning …

Novel Application Of Query-Based Qualitative Predictors For Characterization Of Solvent Accessible Residues In Conjunction With Protein Sequence Homology. Proceedings Of The 22nd International Workshop On Database And Expert Systems Applications, D Rose, R Nepal, S Gholizadeh, R Mishra, R Lau, Brooke Lustig

Faculty Publications, Chemistry

No abstract provided.

Microfluidic Paper-Based Analytical Devices: From Pocket To Paper-Based Elisa, Andres W. Martinez

Chemistry and Biochemistry

Microfluidic paper-based analytical devices (microPADs) began as a simple idea with an ambitious goal. The idea was to make microfluidic devices out of paper instead of plastic or glass. The goal was to develop low-cost and portable paper-based diagnostic devices to improve healthcare in developing countries. Over the past 6 years, many developments have been made in the emerging field of paper-based microfluidic devices. Reviewing the development of these devices in the Whitesides group at Harvard University (Cambridge, MA, USA) can provide some insight into the future of the field and encourage scientists from a variety of backgrounds to contribute …

Better Biomolecule Thermodynamics From Kinetics, Kiran Girdhar, Gregory Scott, Yann R. Chemla, Martin Gruebele

Chemistry and Biochemistry

Protein stability is measured by denaturation: When solvent conditions are changed (e.g., temperature, denaturant concentration, or pH) the protein population switches between thermodynamic states. The resulting denaturation curves have baselines. If the baselines are steep, nonlinear, or incomplete, it becomes difficult to characterize protein denaturation. Baselines arise because the chromophore probing denaturation is sensitive to solvent conditions, or because the thermodynamic states evolve structurally when solvent conditions are changed, or because the barriers are very low (downhill folding). Kinetics can largely eliminate such baselines: Relaxation of chromophores, or within thermodynamic states, is much faster than the transition over activation …

The Fire Inventory From Ncar (Finn): A High Resolution Global Model To Estimate The Emissions From Open Burning, C. Wiedinmyer, S. K. Akagi, Robert J. Yokelson, L. K. Emmons, J. A. Al-Saadi, J. J. Orlando, A. J. Soja

Chemistry and Biochemistry Faculty Publications

The Fire INventory from NCAR version 1.0 (FINNv1) provides daily, 1 km resolution, global estimates of the trace gas and particle emissions from open burning of biomass, which includes wildfire, agricultural fires, and prescribed burning and does not include biofuel use and trash burning. Emission factors used in the calculations have been updated with recent data, particularly for the non-methane organic compounds (NMOC). The resulting global annual NMOC emission estimates are as much as a factor of 5 greater than some prior estimates. Chemical speciation profiles, necessary to allocate the total NMOC emission estimates to lumped species for use by …

Emission Factors For Open And Domestic Biomass Burning For Use In Atmospheric Models, S. K. Akagi, Robert J. Yokelson, C. Wiedinmyer, M. Alvarado, J. S. Reid, T. Karl, J. D. Crounse, P. O. Wennberg

Chemistry and Biochemistry Faculty Publications

Biomass burning (BB) is the second largest source of trace gases and the largest source of primary fine carbonaceous particles in the global troposphere. Many recent BB studies have provided new emission factor (EF) measurements. This is especially true for non-methane organic compounds (NMOC), which influence secondary organic aerosol (SOA) and ozone formation. New EF should improve regional to global BB emissions estimates and therefore, the input for atmospheric models. In this work we present an up-to-date, comprehensive tabulation of EF for known pyrogenic species based on measurements made in smoke that has cooled to ambient temperature, but not yet …

Airborne And Ground-Based Measurements Of The Trace Gases And Particles Emitted By Prescribed Fires In The United States, I. R. Burling, Robert J. Yokelson, S. K. Akagi, S. P. Urbanski, C. E. Wold, David W. T. Griffith, T. J. Johnson, J. Reardon, D. R. Weise

Chemistry and Biochemistry Faculty Publications

We have measured emission factors for 19 trace gas species and particulate matter (PM2.5) from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as conifer forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps to close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning …

Trace Gas And Particle Emissions From Open Biomass Burning In Mexico, Robert J. Yokelson, I. R. Burling, S. P. Urbanski, E. Atlas, K. Adachi, P. R. Buseck, C. Wiedinmyer, S. K. Akagi, D. W. Toohey, C. E. Wold

Chemistry and Biochemistry Faculty Publications

We report airborne measurements of emission factors (EF) for trace gases and PM(2.5) made in southern Mexico in March of 2006 on 6 crop residue fires, 3 tropical dry forest fires, 8 savanna fires, 1 garbage fire, and 7 mountain pine-oak forest fires. The savanna fire EF were measured early in the local dry season and when compared to EF measured late in the African dry season they were at least 1.7 times larger for NO(x), NH(3), H(2), and most non-methane organic compounds. Our measurements suggest that urban deposition and high windspeed may also be associated with significantly elevated NOx …

Boreal Forest Fire Emissions In Fresh Canadian Smoke Plumes: C-1-C-10 Volatile Organic Compounds (Vocs), Co2, Co, No2, No, Hcn And Ch3cn, Isobel J. Simpson, S. K. Akagi, B. Barletta, N. J. Blake, Y. Choi, G. S. Diskin, A. Fried, H. E. Fuelberg, S. Meinardi, F. S. Rowland, S. A. Vay, A. J. Weinheimer, P. O. Wennberg, P. Wiebring, A. Wisthaler, M. Yang, Robert J. Yokelson, Donald R. Blake

Chemistry and Biochemistry Faculty Publications

Boreal regions comprise about 17% of the global land area, and they both affect and are influenced by climate change. To better understand boreal forest fire emissions and plume evolution, 947 whole air samples were collected aboard the NASA DC-8 research aircraft in summer 2008 as part of the ARCTAS-B field mission, and analyzed for 79 non-methane volatile organic compounds (NMVOCs) using gas chromatography. Together with simultaneous measurements of CO2, CO, CH4, CH2O, NO2, NO, HCN and CH3CN, these measurements represent the most comprehensive assessment of trace gas emissions from boreal forest fires to date. Based on 105 air samples …

Nmr Solution Structures Of Two Hairpins Of E. Coli 16s Rrna: The Effects Of Mutations And Chemical Modifications On Structure And Function Of Rrna, Yu Liu

Wayne State University Dissertations

The structures of two functional mutants, the UC (G690U, U697C) and the QM mutants (G690A, G693C, A695C, U697A) of the 690 hairpin of E. coli 16S ribosomal RNA were determined by NMR. The UC mutant and the QM mutant with high biological function are able to fold into structures that are isomorphous with the wild-type 690 hairpin sequence. The structural comparisons among the functional mutants and the wild-type provides structural validation for previously identified specific functional groups that are crucial for maintaining function of the 690 hairpin. The key groups for maintaining the structure and function of the 690 loop …

Exploring Potential Drug Target Sites In The Ribosome Using Cisplatin And Its Analogues, Keshab Rijal

Wayne State University Dissertations

Cis-diamminodichloridoplatinum (II), cisplatin, is an antitumor drug that has been used to treat several types of cancers. The reaction of cisplatin with DNA has been studied and discussed extensively in the literature; however, the effects of cisplatin on RNA function are poorly understood. In this thesis, two aspects of cisplatin, its preferred sites of interaction with RNA and its use as a chemical probe to gain accessibility information, were explored.

To understand the site-selectivity of cisplatin with RNA, model RNA constructs and full-length 16S rRNA were employed. The binding studies revealed a cisplatin preference for guanosine-rich sequences. Primer extensions in …

Study Of Protein-Rna Interactions Using Fluorescence Resonance Energy Transfer (Fret) And Single-Molecule Fret, Rajan Lamichhane

Wayne State University Dissertations

In the cell, RNA and protein, interact to form ribonucleoprotein complexes (RNPs) that have vital structural, catalytic and regulatory roles. Despite their functional importance, the mechanistic details and dynamics of RNPs are poorly understood. Single-molecule Fluorescence Resonance Energy Transfer (smFRET) techniques that provide information about heterogeneity and dynamic behaviors of molecules have been developed to investigate inter- and intra-molecular interactions. Here we have used FRET in combination with smFRET to study three very different RNP systems.

Alternative splicing is a highly regulated biological process that plays a crucial role in proteomic diversity in eukaryotes. One splicing regulator, PTB, has been …

Characterization Of Splicing Mechanisms By Single-Molecule Fluorescence, Krishanthi Sanjeewani Karunatilaka

Wayne State University Dissertations

Group II introns rank amongst the largest self-splicing ribozymes found in bacteria and organellar genomes of various eukaryotes. Despite the diversity in primary sequences, group II introns posses highly conserved secondary structures consisting of six domains (D1-D6). To perform its function, the large multidomain group II intron RNA must adopt the correctly folded structure. As a result, in vitro splicing of these introns requires high ionic strength and elevated temperatures. In vivo, this process is mainly assisted by protein cofactors. However, the exact mechanism of protein-mediated splicing of group II intron RNA is still not known.

In order to …

Development Of Chemical Inducers Of Dimerization For Screening Competitive Histone Deactelyase Inhibitors, Emily Lynn Aubie

Wayne State University Dissertations

Histone Deacetylase (HDAC) proteins are transcriptional regulators that affect histone proteins, which are involved in packaging of DNA into chromosomes. HDACs have been linked to the proliferation of cancer through their role in transcriptional regulation. Due to these findings, HDAC inhibitors have been explored as anti-cancer agents. Several HDAC inhibitors are currently in various stages of clinical trials, and the inhibitor suberoyl anilide hydroxamic acid (SAHA) has been FDA approved for treatment of cutaneous T-Cell lymphoma. Currently, most of the known HDAC inhibitors are non-selective, which causes non-specific binding to the active sites of all HDAC isoforms, including those not …

Mne1 Is A Novel Component Of The Mitochondrial Splicing Apparatus Responsible For Processing Of A Cox1 Group I Intron In Yeast, Talina Watts, Oleh Khalimonchuk, Rachel Z. Wolf, Edward M. Turk, Georg Mohr, Dennis R. Winge

Department of Biochemistry: Faculty Publications

Saccharomyces cerevisiae cells lacking Mne1 are deficient in

intron splicing in the gene encoding the Cox1 subunit of cytochrome

oxidase but contain wild-type levels of the bc1 complex.

Thus, Mne1 has no role in splicing of COB introns or expression

of the COB gene. Northern experiments suggest that splicing of

the COX1 aI5β intron is dependent on Mne1 in addition to the

previously known Mrs1, Mss116, Pet54, and Suv3 factors. Processing

of the aI5_ intron is similarly impaired in mne1∆ and

mrs1∆ cells and overexpression of Mrs1 partially restores the

respiratory function of mne1∆ cells. Mrs1 …

Method Development And Applications To Screening And Characterization Of Rrna-Targeting Small Molecules, Papa Nii Asare-Okai

Wayne State University Dissertations

A series of single ring aminoglycoside analogues was tested for binding to a model RNA representing the A site using electrospray ionization mass spectrometry (ESI-MS). Several of the synthetic analogues with low molecular weights were found to bind to the RNA with affinities comparable to the parental aminoglycoside neamine, with apparent dissociation constants in the low micromolar range. Salt dependence of the affinity constants for the single ring analogues revealed a predominantly electrostatic binding mode. Footprinting experiments revealed that one of the compounds (DHR23) has a similar binding site as the antibiotic paromomycin. DMS chemical probing results also suggest that …

Molecular Details Of The Mitochondrial Iron Sulfur Cluster Assembly Pathway, Swati Rawat

Wayne State University Dissertations

MOLECULAR DETAILS OF THE MITOCHONDRIAL IRON SULFUR CLUSTER ASSEMBLY PATHWAY

Iron-sulfur clusters are an important class of prosthetic group involved in electron transfer, enzyme catalysis, and regulation of gene expression. Their biosynthesis requires complex machinery located within the mitochondrion since free iron and sulfide are extremely toxic to the cell. Defects in this pathway results in several diseases such as Friedreich's Ataxia (FRDA), Sideroblastic Anemia and ISCU Myopathy. Therefore molecular details of the biogenesis pathway will provide deep insight in the pathway and treatment options for these diseases. FRDA is caused by deficiency of a single protein called as `Frataxin'. …

Dynamic Light Scattering And Zeta Potential Of Colloidal Mixtures Of Amelogenin And Hydroxyapatite In Calcium And Phosphate Rich Ionic Milieus, Vuk Uskoković, Roselyn Odsinada, Sonia Djordjevic, Stefan Habelitz

Pharmacy Faculty Articles and Research

The concept of zeta-potential has been used for more than a century as a basic parameter in controlling the stability of colloidal suspensions, irrespective of the nature of their particulate ingredients – organic or inorganic. There are prospects that self-assembly of peptide species and the protein-mineral interactions related to biomineralization may be controlled using this fundamental physicochemical parameter. In this study, we have analyzed the particle size and zeta-potential of the full-length recombinant human amelogenin (rH174), the main protein of the developing enamel matrix, in the presence of calcium and phosphate ions and hydroxyapatite (HAP) particles. As calcium and phosphate …

Altered Self-Assembly And Apatite Binding Of Amelogenin Induced By N-Terminal Proline Mutation, Li Zhu, Vuk Uskoković, Thuan Le, Pamela Denbesten, Yulei Huang, Stefan Habelitz, Wu Li

Pharmacy Faculty Articles and Research

Objective—A single Pro-70 to Thr (p.P70T) mutation of amelogenin is known to result in hypomineralized amelogenesis imperfecta (AI). This study aims to test the hypothesis that the given mutation affects the self-assembly of amelogenin molecules and impairs their ability to conduct the growth of apatite crystals.

Design—Recombinant human full-length wild-type (rh174) and p.P70T mutated amelogenins were analyzed using dynamic light scattering (DLS), protein quantification assay and atomic force microscopy (AFM) before and after the binding of amelogenins to hydroxyapatite crystals. The crystal growth modulated by both amelogenins in a dynamic titration system was observed using AFM.

Results—As …

Targeted Identification Of Metastasis-Associated Cell-Surface Sialoglycoproteins In Prostate Cancer, Lifang Yang, Julius O. Nyalwidhe, Sigi Guo, Richard R. Drake, O. John Semmes

Bioelectrics Publications

Covalent attachment of carbohydrates to proteins is one of the most common post-translational modifications. At the cell surface, sugar moieties of glycoproteins contribute to molecular recognition events involved in cancer metastasis. We have combined glycan metabolic labeling with mass spectrometry analysis to identify and characterize metastasis-associated cell surface sialoglycoproteins. Our model system used syngeneic prostate cancer cell lines derived from PC3 (N2, nonmetastatic, and ML2, highly metastatic). The metabolic incorporation of AC₄ManNAz and subsequent specific labeling of cell surface sialylation was confirmed by flow cytometry and confocal microscopy. Affinity isolation of the modified sialic-acid containing cell surface proteins …