Biochemistry, Biophysics, and Structural Biology Commons^™

Study On The Wistar Rat Liver And Its Walker Tumor Chromatins By Fluorescence Lifetime And Calorimetric Measurements, Jianfei Zhao

Jianfei Zhao

Quality Control And Peak Finding For Proteomics Data Collected From Nipple Aspirate Fluid Using Surface Enhanced Laser Desorption And Ionization., Jeffrey S. Morris, Kevin R. Coombes, Herbert A. Fritsche, Charlotte Clarke, Jeng-Neng Chen, Keith A. Baggerly, Lian-Chun Xiao, Mien-Chie Hung, Henry M. Kuerer

Jeffrey S. Morris

Background: Recently, researchers have been using mass spectroscopy to study cancer. For use of proteomics spectra in a clinical setting, stringent quality-control procedures will be needed.

Methods: We pooled samples of nipple aspirate fluid from healthy breasts and breasts with cancer to prepare a control sample. Aliquots of the control sample were used on two spots on each of three IMAC ProteinChip® arrays (Ciphergen Biosystems, Inc.) on 4 successive days to generate 24 SELDI spectra. In 36 subsequent experiments, the control sample was applied to two spots of each ProteinChip array, and the resulting spectra were analyzed to determine how ...

Metabolic Responses Of Shorebird Chicks To Cold Stress: Hysteresis Of Cooling And Warming Phases, Robert E. Ricklefs, Joseph B. Williams

Robert Ricklefs

Multiple Luteinizing Hormone Receptor (Lhr) Protein Variants, Interspecies Reactivity Of Anti-Lhr Mab Clone 3b5, Subcellular Localization Of Lhr In Human Placenta, Pelvic Floor And Brain, And Possible Role For Lhr In The Development Of Abnormal Pregnancy, Pelvic Floor Disorders And Alzheimer's Disease, A Bukovsky, K Indrapichate, H Fujiwara, Maria Cekanova Ms, Rndr, Phd, Me Ayala, R Dominguez, Mr Caudle, J Wimalsena, Rf Elder, P Copas, Jf Foster, Ri Fernando, Dc Henley, Nb Upadhyaya

Maria Cekanova MS, RNDr, PhD

Distinct luteinizing hormone receptor (LHR) protein variants exist due to the posttranslational modifications. Besides ovaries, LHR immunoreactivity (LHRI) was also found in other tissues, such as the brain, fallopian tube, endometrium, trophoblast and resident tissue macrophages. The 3B5 mouse monoclonal antibody was raised against purified rat LHR. In rat, porcine and human ovaries, the 3B5 identified six distinct LHR bands migrating at approximately 92, 80, 68, 59, 52 and 48 kDa. Characteristic LHRI was detected in rat, human and porcine corpora lutea. During cellular differentiation, subcellular LHR distribution changed from none to granular cytoplasmic, perinuclear, surface, nuclear and no staining ...

A Comprehensive Approach To The Analysis Of Maldi-Tof Proteomics Spectra From Serum Samples., Keith A. Baggerly, Jeffrey S. Morris, Jing Wang, David Gold, Lian-Chun Xiao, Kevin R. Coombes

Jeffrey S. Morris

For our analysis of the data from the First Annual Proteomics Data Mining Conference, we attempted to discriminate between 24 disease spectra (group A) and 17 normal spectra (group B). First, we processed the raw spectra by (i) correcting for additive sinusoidal noise (periodic on the time scale) affecting most spectra, (ii) correcting for the overall baseline level, (iii) normalizing, (iv) recombining fractions, and (v) using variable- width windows for data reduction. Also, we identified a set of polymeric peaks (at multiples of 180.6 Da) that is present in several normal spectra (B1–B8). After data processing, we found ...

Endogenous Oxidoreductase Expression Is Induced By Aminoglycosides, George Hoppe, Yuh-Cherng Chai, Jonathan Sears

Yuh-Cherng Chai

Oxidoreductases such as glutaredoxin are a major class of enzymes that reversibly catalyze thiol-disulfide exchange reactions. Transfection experiments using geneticin (G418) selection to identify the specific protein S-thiolated substrates of glutaredoxin-1 (Grx-1) noted the curious phenomenon that nontransfected control cells treated with G418 had increased levels of Grx-1 expression. Varied concentrations of gentamicin, kanamycin, and hygromycin increased Grx-1 expression in a time- and dose-dependent fashion in human cultured retinal pigment epithelial cells. Reactive oxygen species formation after aminoglycoside exposure correlated directly to aminoglycoside treatment. Further indication that oxidation regulates Grx-1 expression was noted by the positive effect of phorbol 12-myristate ...

Gene Expression In Cadmium-Tolerant Datura Innoxia: Detection And Characterization Of Cdnas Induced In Response To Cd2+, Maggie Louie, Nathan Kondor, Jane G. Dewitt

Maggie Louie

Placental Expression Of Estrogen Receptor Beta And Its Hormone Binding Variant--Comparison With Estrogen Receptor Alpha And A Role For Estrogen Receptors In Asymmetric Division And Differentiation Of Estrogen-Dependent Cells., A Bukovsky, M Caudle, Maria Cekanova, R Fernando, J Wimalasena, J Foster, D Henley, R Elder

Maria Cekanova MS, RNDr, PhD

During human pregnancy, the production of 17-beta-estradiol (E2) rises steadily to eighty fold at term, and placenta has been found to specifically bind estrogens. We have recently demonstrated the expression of estrogen receptor alpha (ER-alpha) protein in human placenta and its localization in villous cytotrophoblast (CT), vascular pericytes, and amniotic fibroblasts. In vitro, E2 stimulated development of large syncytiotrophoblast (ST) aggregates. In the present study we utilized ER-beta affinity purified polyclonal (N19:sc6820) and ER-alpha monoclonal (clone h-151) antibodies. Western blot analysis revealed a single approximately 52 kDa ER-beta band in chorionic villi (CV) protein extracts. In CV, strong cytoplasmic ...

Dependence Of Endoplasmic Reticulum-Associated Degradation On The Peptide Binding Domain And Concentration Of Bip, Mehdi Kabani, Stephanie Kelley, Michael Morrow, Diana Montgomery, Renuka Sivendran, Mark Rose, Lila Gierasch, Jeffrey Brodsky

Lila Gierasch

ER-associated degradation (ERAD) removes defective and mis-folded proteins from the eukaryotic secretory pathway, but mutations in the ER lumenal Hsp70, BiP/Kar2p, compromise ERAD efficiency in yeast. Because attenuation of ERAD activates the UPR, we screened for kar2 mutants in which the unfolded protein response (UPR) was induced in order to better define how BiP facilitates ERAD. Among the kar2 mutants isolated we identified the ERAD-specific kar2-1 allele (Brodsky et al. J. Biol. Chem. 274, 3453–3460). The kar2-1 mutation resides in the peptide-binding domain of BiP and decreases BiP's affinity for a peptide substrate. Peptide-stimulated ATPase activity was ...

Bayesian Shrinkage Estimation Of The Relative Abundance Of Mrna Transcripts Using Sage, Jeffrey S. Morris, Keith A. Baggerly, Kevin R. Coombes

Jeffrey S. Morris

Serial analysis of gene expression (SAGE) is a technology for quantifying gene expression in biological tissue that yields count data that can be modeled by a multinomial distribution with two characteristics: skewness in the relative frequencies and small sample size relative to the dimension. As a result of these characteristics, a given SAGE sample may fail to capture a large number of expressed mRNA species present in the tissue. Empirical estimators of mRNA species’ relative abundance effectively ignore these missing species, and as a result tend to overestimate the abundance of the scarce observed species comprising a vast majority of ...

Bifunctional Abietadiene Synthase: Mutual Structural Dependence Of The Active Sites For Protonation-Initiated And Ionization-Initiated Cyclizations, Reuben J. Peters, Ora A. Carter, Yan Zhang, Brian W. Matthews, Rodney B. Croteau

Reuben J. Peters

Abietadiene synthase from grand fir catalyzes two sequential, mechanistically distinct cyclizations, of geranylgeranyl diphosphate and of copalyl diphosphate, in the formation of a mixture of abietadiene isomers as the committed step of diterpenoid resin acid biosynthesis. Each reaction is independently conducted at a separate active site residing in what were considered to be structurally distinct domains typical of terpene cyclases. Despite the presence of an unusual 250-residue N-terminal insertional element, a tandem pair of charged residues distal to the insertion was shown to form a functional part of the C-terminal active site. Because abietadiene synthase resembles the ancestral plant terpene ...

Expression And Localization Of Estrogen Receptor-Alpha Protein In Normal And Abnormal Term Placentae And Stimulation Of Trophoblast Differentiation By Estradiol, A Bukovsky, Maria Cekanova Ms, Rndr, Phd, Mr Caudle, J Wimalasena, Js Foster, Dc Henley, Rf Elder

Maria Cekanova MS, RNDr, PhD

Estrogens play an important role in the regulation of placental function, and 17-beta-estradiol (E2) production rises eighty fold during human pregnancy. Although term placenta has been found to specifically bind estrogens, cellular localization of estrogen receptor alpha (ER-alpha) in trophoblast remains unclear. We used western blot analysis and immunohistochemistry with h-151 and ID5 monoclonal antibodies to determine the expression and cellular localization of ER-alpha protein in human placentae and cultured trophoblast cells. Western blot analysis revealed a ~65 kDa ER-alpha band in MCF-7 breast carcinoma cells (positive control). A similar band was detected in five normal term placentae exhibiting strong ...

Reversal Of Protein S-Glutathiolation By Glutaredoxin In The Retinal Pigment Epithelium., Yuh-Cherng Chai, George Hoppe, Jonathan Sears

Yuh-Cherng Chai

Protein cysteines can serve both sensory and activation roles in the regulation of protein function. The modulation of mixed disulfides with glutathione may promise to be a broad mechanism of redox signalling. Using both protein extract and intact RPE cells, we have generated covalent adduction of glutathione to protein cysteines and further show that glutaredoxin (Grx-1) is able to remove glutathione from protein S-glutathiolated substrates. Our data demonstrate that glutathione can modify a wide range of RPE proteins in intact cells, but that the reversal of this process–deglutathiolation and thiol bond restoration–may require a specific catalytic reaction with ...

Hormesis And Stage Specific Toxicity Induced By Cadmium In An Insect Model, The Queen Blowfly, Phormia Regina Meig., Marc Nascarella, John Stoffolano, Jr., Edward Stanek, Iii, Paul Kostecki, Edward Calabrese

Paul T. Kostecki

No abstract provided.

A Model For Ethylene Receptor Function And 1-Methylcyclopropene Action, Brad Binder, A. Bleecker

Brad M. Binder

This paper provides a comprehensive review of current understanding of ethylene receptors, signal transduction using Arabidopsis as the model plant. It discusses the current theory on the mechanism of ethylene binding and proposes a mechanism for the action of ethylene response inhibitors such as 1-MCP.

Placental Expression Of Estrogen Receptor Beta And Its Hormone Binding Variant – Comparison With Estrogen Receptor Alpha And A Role For Estrogen Receptors In Asymmetric Division And Differentiation Of Estrogen-Dependent Cells, Antonin Bukovsky, Michael R. Caudle, Maria Cekanova Ms, Rndr, Phd, Romaine I. Fernando, Jay Wimalasena, James S. Foster, Donald C. Henley, Robert F. Elder

Maria Cekanova MS, RNDr, PhD

During human pregnancy, the production of 17-beta-estradiol (E2) rises steadily to eighty fold at term, and placenta has been found to specifically bind estrogens. We have recently demonstrated the expression of estrogen receptor alpha (ER-alpha) protein in human placenta and its localization in villous cytotrophoblast (CT), vascular pericytes, and amniotic fibroblasts. In vitro, E2 stimulated development of large syncytiotrophoblast (ST) aggregates. In the present study we utilized ER-beta affinity purified polyclonal (N19:sc6820) and ER-alpha monoclonal (clone h-151) antibodies. Western blot analysis revealed a single ~52 kDa ER-beta band in chorionic villi (CV) protein extracts. In CV, strong cytoplasmic ER-beta ...

Hormesis And Stage Specific Toxicity Induced By Cadmium In An Insect Model, The Queen Blowfly, Phormia Regina Meig., Marc A. Nascarella, John G. Stoffolano, Jr., Edward J. Stanek, Iii, Paul T. Kostecki, Edward J. Calabrese

Edward Calabrese

No abstract provided.

Actin-Depolymerizing Factor Mediates Rac/Rop Gtpase-Regulated Pollen Tube Growth, C, Y, Chen, Alice Cheung, H. M. Wu

Alice Cheung

Pollen tube elongation is a rapid tip growth process that is driven by a dynamic actin cytoskeleton. A ubiquitous family of actin binding proteins, actin-depolymerizing factors (ADFs)/cofilins, bind to actin filaments, induce severing, enhance depolymerization from their slow-growing end, and are important for maintaining actin dynamics in vivo. ADFs/cofilins are regulated by multiple mechanisms, among which Rho small GTPase-activated phosphorylation at a terminal region Ser residue plays an important role in regulating their actin binding and depolymerizing activity, affecting actin reorganization. We have shown previously that a tobacco pollen-specific ADF, NtADF1, is important for maintaining normal pollen tube ...

The European Commission's Ge/Honeywell Decision: U.S. Responses And Their Implications, David J. Gerber

David J. Gerber

No abstract provided.