bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-Sufficiency of Rice Consumption and Farm Entrepreneurship of Operating Farmers in Rural Areas of West Bengal, India: An Empirical Interpretation from Socio-Personal, Agro-Economic, Socio-Psychological and Communicative Variables
Authors: Roy Debraj , Ghoshal Swagata , Acharya S. K. , Ghosh Arindam , Mazumder Debashis , Biswas Amitava
Published: November 2020

Aims: The major objectives of the study are to elucidate the distributive characters of operating farms in the selected locale of the study, to delineate a micro level policy so that the constraints of the operating farms can be analyzed and intervention programmes can be operationally described, to estimate and analyze the nature and direction of interaction among the independent and dependent variables.

Study Design: The locale was selected by purposive as well as simple random sampling techniques and the respondents following rice cultivation had been interacted and were selected by the simple random sampling method.

Place of Study: Village Rasulpur of Memari-1 block of Purba Bardhaman district in West Bengal was purposively selected for the study.

Methodology: In this study 50 respondents following rice cultivation have been interacted and are selected by the simple random sampling method. A preliminary interview schedule has been administered to understand the knowledge, perception and attitude of the people towards climate changes concept, communication and extension system, farm enterprises, challenges faced during rice production. The collected data had been put into multivariate analysis. Statistical Package for the Social Sciences V20.0 (SPSS) of IBM was used for correlation analysis, multiple regression analysis, step-down regression analysis, path analysis and factor analysis.

Results: Independent variables economic land (x7), group interaction (x11), innovation proneness (x13) and market orientation (x14) have been found to exert strong and determining contribution to estimate dependent variable self-consumption of rice production (y) and the set of economic and ecological variables as selected for the study.

Conclusion: It can be concluded that the dynamics of self-sufficiency of food grains and entrepreneurship, here in case of rice enterprises, are dominantly relying on the entrepreneurs’ behavioural characters, the group interaction they are experiencing, the economic land they are possessing, the electricity consumption level, and the fuel use efficiency, innovation proneness and market interaction.
Potential Impact of Polychlorinated Biphenyls on Plant and Environmental Health
Authors: Monika . , Yadav Abhinav
Published: November 2020

Polychlorinated biphenyls (PCBs) are manufactured natural mixes in which 2-10 chlorine molecules are appended to the biphenyl. They were industrially delivered as intricate blends by the immediate chlorination of biphenyls utilizing anhydrous chlorine. Hypothetically 209 individual PCB mixes are conceivable, however just around 130 congeners have been distinguished in commercial PCB blends. Even though their properties fluctuate over a class, all PCBs are insoluble in water and diligent in both the earth and inside natural frameworks. They are profoundly lipophilic and along these lines tend to bioaccumulate and bio magnify in tissues of living life forms. In view of their concoction and physical solidness and electrical protecting properties, they have had a variety of uses in industry included generally as coolants and greases in transformers, capacitors, and other electrical types of gear. PCBs are present in environment adversely affect the plants properties such as biochemical, physiological, enzymatic and ultimately enters into the human via food chain. This review is an approach emphasizes on potential impact on PCBs on environment.
A Review of Radiographic Findings in Sars-Cov-2 Patients
Authors: Santana Denise Freitas , Melo Kárita Amanda Ribeiro de , Neto Agrinazio Geraldo Nascimento , Silva Wellington Carlos da , Santos Fábio Alves dos , Barros Amanda Aguiar , Silva Maisa Adriele Nalves da , Oliveira Lívia Gomes de , Carvalho Leidimar da Silva , Batista Taynara Dantas , Santos Larissa Lima dos , Nery Bianca de Andrade , Reis Murilo de Sousa , Borges Yan de Lima
Published: November 2020

Introduction: At the end of 2019, more specifically in December, the outbreak of the new coronavirus - Sars-Cov-2, which caused pneumonia, emerged in Wuhan, and soon spread throughout China, where researchers began to suspect a possible pandemic. , being a disease that causes a deficiency of structures of the respiratory system, leading to alterations in breathing functions, with respiratory muscle deficiencies and exercise tolerance. During the pandemic peak still in Wuhan, the main radiographic findings in hospitalized patients revealed bilateral opacity on computed tomography (CT) examination, lobular and subsegmental consolidation areas, ground-glass opacities, consolidation with rounded morphology, and peripheral pulmonary distribution.

Aims: Analyze through the available literature review the main radiological alterations caused by Sars-Cov-2.

Methodology: This is an integrative literature review using PubMed, Scielo, Google Scholar, Microsoft Academic databases. Inclusion criteria were complete and original articles in English and Portuguese. Duplicates and other literature reviews were excluded.

Results: Radiographic findings are different in the early and advanced phases of the disease, but characteristic signs such as the matte glass pattern were found in both phases.

Conclusion: The radiographic findings of patients diagnosed with COVID-19 are not the main criteria for clinical diagnosis, but knowledge of characteristic symptoms is fundamental. Therefore, the multidisciplinary team must discuss the radiological findings most common to the virus, this will directly aid early diagnosis, in addition to reducing the high mortality rates globally.
Formulation, Characterization and in-vitro Evaluation of Famciclovir Loaded Solid Lipid Nanoparticles for Improved Oral Absorption
Authors: Rawat Pavan Kumar , Tyagi Chandra Kishore , Shah Sunil Kumar , Pandey Arun Kumar
Published: November 2020

Famciclovir loaded Solid Lipid Nanoparticles (SLNs) using triglycerides as solid lipids were successfully prepared using the double emulsion-solvent evaporation technique. Formulation parameters like amount and type of lipid and level of surfactants affected the nanoparticle characters. It was observed that nanoparticle characters like average particle size and distribution, drug content, entrapment efficiency and release pattern were dependent on these formulation variables. The optimized formulations depicted the desired characters of low particle size, in the range of 140-170 nm in case of Glyceryl monostearate (GMS) and glyceryl distearate (GDS) SLNs and 250-340 nm in case of glyceryl behenate (GB) SLNs and entrapment efficiencies in the range of 35-48%. In vitro drug release was extended upto 8 h and the release profile was explained by the Baker-Lonsdale model for spherical particles. Morphological examination by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) displayed homogenous solid, spherical and non- porous particles. The formulations depicted good redispersibility after lyophilization and presence of residual solvents in the formulations within the prescribed limits suggested suitability of the preparation technique. Freeze- dried formulations were found to be stable in terms of particle size and drug loading even after 6 months of storage at refrigerated conditions.
Density gradient equilibrium methods applied to blood‐group specific glycoproteins
Authors: Creeth J.M. , Denborough M.A.
Published: July 2002

The blood‐group specific glycoproteins of human ovarian cyst fluids have been isolated by equilibrium density gradient centrifugation in CsCl; they have been characterised in terms of buoyant density, selective salvation and apparent molecular weight, both in CsCl and Cs2SO4.
Use of monoclonal and polyclonal antibodies as structural and topographical probes for hepatic epoxide hydrolase
Authors: Wolf C.Roland , Oesch Franz , Timms Christopher , Guenthner Thomas , Hartmann Renate , Maruhn Monika , Burger Reinhard
Published: July 2002

Monoclonal antibodies have been prepared against rat liver epoxide hydrolase (EH), some of which gave precipitation lines on immunodiffusion against pure EH suggesting the presence of repetitive structural domains on the enzyme. Using ELISA, with polyclonal antibodies to rat and rabbit liver EH, reactivity and therefore structural similarities between EH of all species tested, including human, were observed. This was in contrast to immunodiffusion results demonstrating the limitations of the latter technique. Using monoclonal antibodies in ELISA, greatest structural similarity was between rat, mouse, and Syrian hamster EH and relatively little between rat and human. Two of the antibodies reacted with nearly all species tested and may be directed towards critical sites on the enzyme. This and most of the EH molecule would appear to be localised on the cytoplasmic surface of the endoplasmic reticulum.
Interaction of antimycin with cytochrome b‐561
Authors: Malviya A.N. , Rendon A. , Aunis D.
Published: July 2002

Cytochrome b‐561 in chromaffin granules interacts with antimycin and its α‐peak shifts 1 nm towards red. When chromaffin granules were treated with Triton X‐100 antimycin no effect was observed. Cytochrome b‐561 is located in the plasma membrane isolated from the chromaffin cells. The plasma membrane b‐561 does not seem to interact with antimycin. A number of NADH or NADPH (acceptor) oxidoreductase activity has been observed in isolated plasma membrane providing clues to the origin of plasma membrane dehydrogenase. The possible role of cytochrome b561 in secretory granules other than its accredited energy conserving electron transport property is projected.
Use of the pH sensitive fluorescence probe pyranine to monitor internal pH changes in Escherichia coli membrane vesicles
Authors: Damiano E. , Bassilana M. , Rigaud J.-L. , Leblanc G.
Published: July 2002

Measurements of the fluorescent properties of 8‐hydroxy‐1,3,6‐pyrenetrisulfonate (pyranine) enclosed within the internal space of Escherichia coli membrane vesicles enable recordings and quantitative analysis of: (i) changes in intravesicular pH taking place during oxidation of electron donors by the membrane respiratory chain; (ii) transient alkalization of the internal aqueous space resulting from the creation of outwardly directed acetate diffusion gradients across the vesicular membrane. Quantitation of the fluorescence variations recorded during the creation of transmembrane acetate gradients shows a close correspondence between the measured shifts in internal pH value and those expected from the amplitude of the imposed acetate gradients.
Antibody against globular domain of H1° histone
Authors: Yasuda Hideyo , Logan Kathleen Ann , Morton Bradbury E.
Published: July 2002

Antibodies against the globular domain of histones H1° and H5 were developed in rabbit. The antibody against the globular domain of H5 cross‐reacted with H1° but not with H1; the antibody against the globular domain of H1° did not cross‐react with H5, H1 or with HMG proteins. The globular domain of H1° therefore appears to have an immunological determinant(s) which does not exist in H1 and H5. By use of these antibodies, we show that nucleated erthrocytes of bullfrog contain an H1°‐like protein (not an H5‐like protein). This observation coincided with the report of Shimada, T. [J. Biol. Chem. 256 (1981) 10577–10582]. These antibodies have application in detecting H1°‐like proteins in eukaryotic cells.
Two diverse effects of poly(L‐lysine) on rabbit skeletal muscle phosphorylase kinase: stimulation of autophosphorylation and inhibition of its activity
Authors: Negami Akira , Sakai Kuniyasu , Kobayashi Tomoko , Tabuchi Hikaru , Nakamura Shun-ichi , Yamamura Hirohei
Published: July 2002

Polylysine greatly stimulated the autophosphorylation of phosphorylase kinase from rabbit skeletal muscle. When fully autophosphorylated, about 14 mol of phosphate per tetramer (αβγδ) were incorporated in the presence of polylysine, which was twice as much as those observed without polylysine. In contrast to this stimulatory effect of polylysine on the autophosphorylation, polylysine strongly inhibited the conversion reaction of phosphorylase b to a. The inhibition is competitive with a K
i of 2.3 μg/ml. No effects of polylysine were observed on the activities of phosphorylase and cAMP‐dependent protein kinase.
Dephosphorylation of phosphorylase kinase by a histone H1‐stimulated phosphoprotein phosphatase
Authors: Mellgren Ronald L. , Wilson Susan E. , Schlender Keith K.
Published: July 2002

A histone H1‐stimulated protein phosphatase isolated from rabbit skeletal muscle dephosphorylated [32P]phosphorylase kinase. The rate of dephosphorylation was markedly increased by 5–50 μg histone H1/ml. Only the α and α' subunits were dephosphorylated in the absence or presence of histone H1. This is consistent with previous results suggesting that the H1‐stimulated phosphatase is a type‐2 protein phosphatase. The present studies suggest that the histone H1‐stimulation is the result of direct interaction of the histone with the phosphatase.
The amino acid sequence of hemoglobin I from Parasponia andersonii, a nonleguminous plant
Authors: Kortt Alexander A. , Burns John E. , Trinick Michael J. , Appleby Cyril A.
Published: July 2002

The complete amino acid sequence of the hemoglobin I from nitrogen‐fixing root nodules of the nonleguminous plant, Parasponia
andersonii, has been determined. This dimeric protein consists of two identical polypeptide chains of 155 amino acids and shows extensive sequence homology with other hemoglobins. Homology between the hemoglobin I of P. andersonii and the leghemoglobins of lupin and soybean nodules is 41 and 39%, respectively. The predicted secondary structure of P. andersonii hemoglobin I has a high content of α‐helix; except for the E‐helix, similar helices were predicted as those in the leghemoglobins. The close homology of the sequences provides evidence that this nonleguminous hemoglobin shares the same genetic origin as the legume and animal hemoglobins.
‘Red pigment’ from ADE‐2 mutants of S. cerevisiae prevents DNA cleavage by restriction endonucleases
Authors: Meškauskas Arturas , Ksenzenko Vladimir , Shlyapnikov Mikhail , Kryukov Valentin , Čitavičius Donaldas
Published: July 2002

Protection of DNA from cleavage by restriction endonucleases EcoRI, HindIII, BamHI, and Bg/II with red pigment, produced by ADE‐2 mutants of Saccharomyces cerevisiae is demonstrated. Purification of yeast DNA from pigment can be achieved by chromatography on hydroxyapatite columns.
Mechanism of activation of H2O2 by peroxidases: kinetic studies on a model system
Authors: Baldwin David A. , Marques Helder M. , Pratt John M.
Published: July 2002

Kinetic studies on the peroxidase activity of microperoxidase‐8 at pH 5.5–8.5 show that the rate is increased by raising the pH or by the presence of guanidinium ion. Comparison with published data on the peroxidases provides evidence that the enzyme activates H2O2 through the cooperative binding of H+ + HO−
2 and suggests a role for the invariant distal Arg.
Initiation of flagellar rotation in Rhodopseudomonas sphaeroides
Authors: Evans Michael C.W. , Armitage Judith P.
Published: July 2002

The collapse of the proton‐motive force (pmf) in dark‐incubated Rps. sphaeroides by the addition of low concentrations of anionic uncouplers caused a loss of motility. When added to bacteria under continuous illumination, the same uncoupler concentration had no effect on motility. Re‐illumination of the nonmotile, dark‐incubated bacteria caused a very fast increase in the pmf, but there was a delay before pmf‐driven flagellar rotation was initiated. The length of the delay, which could be many minutes, was shown to be dependent on the type of uncoupler used, the ΔpH component of the pmf and to be independent of the overall size of the pmf or the temperature. It is concluded that the delay in reinitiation of motility was due to the direct interaction of anionic uncouplers with sites on the flagellar motor proteins.
Oxidation of QA− and of QB− of photosynthetic reaction centers by an artificial acceptor
Authors: Agalidis Ileana , Velthuys Bruno R.
Published: July 2002

Bacterial reaction centers and photosystem II particles reduce N,N,N',N'‐tetramethyl‐p‐phenylenediamine with a rate constant that depends on the state of the acceptor complex. We assume interference by detergent to explain the dissimilar behavior of the two types of material. Using this assumption, we summarize: QA (with an empty QB site) is more reactive than QA
−·X (with an occupied QB site; X = quinone, herbicide, or, we assume, detergent). QA
−·X is more reactive than QA·B
−.
Expression cloning of a cDNA encoding the type II regulatory subunit of the cAMP‐dependent protein kinase
Authors: Hemmings Brian A. , Schwarz Manuela , Rao Adavani S. , Jans David A.
Published: July 2002

We report here the isolation and sequence of a cDNA for the type II regulatory subunit of the cAMP‐dependent protein kinase (cAMP‐PK) from a λgt‐11 cDNA library derived from a porcine epithelial cell line (LLC‐PK1). The cDNA was detected by immunological screening using an affinity purified polyclonal antibody for bovine RII. DNA sequence analysis of the 467 bp EcoRI insert confirmed the identity of the clone, because the deduced amino acid sequence corresponded to the published sequence for the bovine RΠ protein. Northern analysis of total RNA from the LLC‐PK1 cells indicated a single mRNA species of about 6.0 kb, probably derived from a single copy gene.
The nucleotide sequence of the amiE gene of Pseudomonas aeruginosa
Authors: Brammar W.J. , Charles I.G. , Matfield M. , Cheng-Pin Liu , Drew R.E. , Clarke Patricia H.
Published: July 2002

The nucleotide sequence of the amiE gene, encoding the aliphatic amidase of Pseudomonas aeruginosa, has been determined. The sequence of 1038 nucleotides shows a strong bias in favour of codons with G or C in the third position, and only 44 different codons are utilised.
The stalk connecting the F1 and F0 domains of ATP synthase visualized by electron microscopy of unstained specimens
Authors: Gogol Edward P. , Lücken Uwe , Capaldi Roderick A.
Published: July 2002

E. coli F1 F0 ATP synthase has been reconstituted into membranes and visualized by electron microscopy of unstained samples preserved in thin layers of amorphous ice. Unlike previous observations in negative stain, these specimens are not exposed to potentially denaturing or perturbing conditions, having been rapidly frozen from well‐defined conditions in which the enzyme is fully active. The structures visualized in views normal to the lipid bilayer clearly show the presence of a narrow stalk approx. 45 Å long, connecting the F1 to the membrane‐embedded F0.
Control of ATP hydrolysis in chloroplasts
Authors: Strotmann Heinrich , Kleefeld Sigrid , Lohse Detlev
Published: July 2002

Dark ATP hydrolysis catalysed by the membrane‐bound preactivated thiol‐modified chloroplast ATPase was measured at constant initial ATP concentration and constant initial phosphate potential c
ATP/c
ADP·cP
i which was adjusted by inverse variation of the concentrations of ADP and Pi. Under these conditions, the rate of ATP hydrolysis is strongly inhibited as the concentration of ADP is increased and the concentration of Pi is decreased. Inhibition is preferentially caused by ADP‐dependent inactivation of ATPase molecules. At low initial ADP concentration, the transmembrane proton gradient generated by effective ATP hydrolysis protects the enzyme from deactivation in spite of progressive accumulation of ADP because energy‐dependent release of ADP counteracts its binding. Deactivation due to incorporation of ADP occurs, however, when the proton gradient decreases as a consequence of exhaustion of substrate ATP.
Characterization of soluble forms of NCAM
Authors: Bock Elisabeth , Edvardsen Klaus , Gibson Ann , Linnemann Dorte , Lyles Joan M. , Nybroe Ole
Published: July 2002

Neural cell adhesion molecule (NCAM) has been described as a family of membrane glycoproteins. However, soluble NCAM immunoreactivity has long been recognized. We here show that soluble NCAM is composed of two quantitatively major polypeptides of M
r 180 000 and 115 000 and two minor components of M
r 160 000 and 145 000. Soluble NCAM was immunochemically identical to membrane NCAM, was polysialylated and carried the HNK‐1 epitope. It only constituted 0.8% of total NCAM in newborn rat brain. Soluble NCAM appeared in neuronal cell culture medium 15–30 min after the start of synthesis preceding accumulation of membrane‐associated NCAM on the cell surface. This indicates that soluble NCAM contains a secreted component.
The ‘cation‐dependent’ mannose 6‐phosphate receptor binds ligands in the absence of divalent cations
Authors: Junghans Ulrich , Waheed Abdul , von Figura Kurt
Published: July 2002

The requirement of divalent cations for binding of the 46 kDa mannose 6‐phosphate receptors to phosphomannan and pentamannose 6‐phosphate‐substituted bovine serum albumin was examined. Receptors from human liver and human brain bound to both affinity ligands in the absence or presence of divalent cations with similar efficiency. The requirement for divalent cations therefore appears not to be necessary for the binding.
The cleavage of β‐chain in bovine fibrinogen DH fragment (95 kDa) leads to a significant increase in its anticlotting activity
Authors: Medved' L.V. , Platonova T.N. , Litvinovich S.V. , Lukinova N.I.
Published: July 2002

It is shown that in the presence of Ca2+ plasmin converts bovine fibrinogen fragment DH (95 kDa) into DLA fragment by the cleavage of its β‐chain Arg372Thr373 bond. DLA fragment consists of two components (82 and 12 kDa) held together by non‐covalent bonds and has 3.5‐fold higher anticlotting activity than DH fragment. The DH to DLA fragment conversion leads to the destabilization of thermolabile domains of the latter without the loss of their compact structure. The results obtained show that the activation of DH fragment by the cleavage of its Arg372Thr373 bond bears some resemblance to the general activation of proenzyme into enzyme.
Multi‐site binding of human nuclear protein to the Alu‐family repeated DNA
Authors: Podgornaya O.I. , Perelygina L.M. , Tomilin N.V.
Published: July 2002

Nuclear protein which selectively binds to the Alu‐family DNA repeat (AFR, Blur8) is partially purified from human HeLa cells using a gel retention assay. At low protein concentrations only a single complex of the protein with AFR is formed (CII). Increasing protein concentrations lead to the gradual disappearance of CII, being replaced by complexes with higher (CI) and lower (CIII, CIV) electrophoretic mobilities. Differential binding of AFR restriction subfragments indicates that multiple protein‐binding sites are present within AFR. We discuss two models explaining the anomalous electrophoretic mobility of CII by DNA bending or looping upon cooperative multi‐site binding of the protein to AFR.
The interaction of MgADP with H+‐ATPase in rat liver mitochondria
Authors: Chernyak B.V. , Dukhovich V.F. , Khodjaev E.Yu.
Published: July 2002

The activating anions are found to induce an unexpectedly high (up to 8‐fold for sulphite) increase of ATPase activity in intact rat liver mitochondria. This effect is not determined by the observed changes in K
m and K
i (ADP) values. The stimulation seems to be caused by dissociation of the inactive complex of ATPase with Mg·ADP. The quantity of this complex formed in the course of ATP hydrolysis is approx. 90% of the total ATPase content in intact mitochondria. The data on toluene‐permeabilized mitochondria suggest that the high content of the complex is a result of the stabilizing effect of some matrix macromolecules.
Cross‐linking of collagen CNBr peptides by ozone or UV light
Authors: Fujimori Eiji
Published: July 2002

Insoluble collagen from rat tail tendon was digested with cyanogen bromide. The resultant peptides were dissolved in 0.1% SDS solution and separated by gel filtration and gel electrophoresis. Cross‐linking occurred in CNBr‐cleaved peptides when they were exposed to ozone or biologically effective UV (300 nm) radiation. The enhancement of a blue fluorescence at 430 nm (excited at 350 nm) was found to be associated with oxidized, cross‐linked peptides. Polymeric peptides, formed in collagen with aging, also exhibited enhanced blue fluorescence.
Role of the carboxyl‐terminal region of the PVP protein (F0I subunit) in the H+ conduction of F0F1 H+‐ATP synthase of bovine heart mitochondria
Authors: Papa Sergio , Guerrieri Ferruccio , Zanotti Franco , Houštěk Josef , Capozza Giuseppe , Ronchi Severino
Published: July 2002

By means of protein sequencing, labelling with thiol reagents and reconstitution studies it is shown that the carboxyl‐terminal region of the PVP protein (F0I subunit, nuclear‐encoded protein of M
r 25000) of mitochondrial F0 promotes transmembrane proton conduction by F0 and the sensitivity of this process to oligomycin.
Complete amino acid sequence of the sarcoplasmic calcium‐binding protein (SCP‐I) from crayfish (Astacus leptodactilus)
Authors: Jauregui-Adell J. , Wnuk W. , Cox J.A.
Published: July 2002

The complete amino acid sequence of the alpha chain of the dimeric sarcoplasmic Ca2+‐binding protein (SCP‐I=α2) from crayfish (Astacus leptodactylus) has been determined by partial automatic sequencing of the peptides derived from tryptic digests of the protein after citraconylation or treatment with 1,2‐cyclohexanedione. Overlapping peptides were obtained by cleavage with o‐iodosobenzoic acid, or digestion with Staphylococcus aureus protease, thermolysin and pepsin. The acetylated N‐terminus was identified by fast atom bombardment mass spectrometry. The monomeric protein contains 192 amino acids and has an M
r of 21 643. The sequence shows the presence of three calcium‐binding sites and perhaps of two others that may be degenerated.
The primary sequence of the PFK‐1 inactivating zinc‐binding protein as deduced from cDNA sequencing Identity of the zinc‐binding protein with rat parathymosin
Authors: Trompeter Hans-Ingo , Brand Ingeborg A. , Söling Hans-Dieter
Published: July 2002

We have recently described the sequence of the Zn2+‐binding domain (43 amino acid residues) of a newly detected Zn2+‐binding protein which reversibly inactivates phosphofructokinase‐1 in a Zn2+‐dependent manner [(1986) J. Biol. Chem. 269, 5895–5900; (1988) Eur. J. Biochem. 177, 561–568]. Here, we describe the primary sequence of this protein based on a full‐length cDNA. A sequence comparison reveals the identity of the Zn2+‐binding protein with a protein called parathymosin‐α.
A protein kinase C‐related enzyme activity in Dictyostelium discoideum
Authors: Ludérus M.E.Eva , Van der Most Robbert G. , Otte Arie P. , Van Driel Roel
Published: July 2002

In crude cell lysates of the cellular slime mould Dictyostelium discoideum we identified a protein kinase C (PKC)‐like enzyme activity. This activity, measured as phosphorylation of a synthetic EGF‐receptor‐derived peptide [(1987) J. Biol. Chem. 262, 772–777], was regulated by Ca2+, phosphatidylserine (PS), 1,2‐dioleoyl‐rac‐glycerol (DG) and the phorbol ester PMA. PS and DG stimulated the enzyme in a synergistic manner. The stimulation by these lipids was, in contrast to what has been found for ‘classical’ mammalian PKC, not dependent on Ca2+. The D. discoideum enzyme was strongly stimulated by nanomolar concentrations of PMA, and inhibited by PKC‐inhibitor staurosporine.
Purification of 25‐hydroxyvitamin D3 24‐hydroxylase from rat kidney mitochondria
Authors: Ohyama Yoshihiko , Hayashi Shin-ichi , Okuda Kyuichiro
Published: July 2002

25‐Hydroxyvitamin D3 24‐hydroxylase was purified to an electrophoretically homogeneous state (M
r=53000) from kidney mitochondria of female rats treated with vitamin D3.
Elevated levels of the guanine nucleotide binding protein, Go, are associated with differentiation of neuroblastoma × glioma hybrid cells
Authors: Mullaney Ian , Milligan Graeme
Published: July 2002

Each of a range of pharmacological agents which function to increase intracellular levels of cAMP caused a morphological ‘differentiation’ of neuroblastoma × glioma hybrid, NG108‐15, cells grown in tissue culture. Associated with this differentiation, increased incorporation of [32P]ADP‐ribose catalysed by pertussis toxin was noted into a band of some 39–40 kDa in membranes derived from these cells. Immunoblotting using two antipeptide antisera which identify different regions of Goα demonstrated marked increases in the levels of this polypeptide in membranes of the differentiated cells. However, levels of the β‐subunit did not increase appreciably with differentiation.
Human nuclear protein interacting with a conservative sequence motif of Alu‐family DNA repeats
Authors: Tomilin N.V. , Bozhkov V.M.
Published: July 2002

Human retrotransposons, Alu‐family DNA repeats (AFRs), have variable nucleotide sequence but conservative short elements, which may have important functions, are also present. In our previous reports we have described human nuclear DNA‐binding protein interacting with AFRs and evidence was presented that the protein recognizes sequence motif 5′‐GGAGGC‐3′ which is conserved in the spacer of RNA polymerase III promoter of AFRs and in the SV40 T‐antigen‐dependent replication origin of AFRS. In this study it was found that double‐stranded synthetic oligonucleotides containing indicated conservative sequences of AFRs actually have high‐affinity binding site for HeLa nuclear protein. The data suggest that non‐infected human cells contain nuclear DNA‐binding protein which recognizes the conservative sequence motif of AFRs — GGAGGC.
The H+ ATPase regulatory subunit of Methanococcus thermolithotrophicus: Amplification of an 800 bp fragment by polymerase chain reaction
Authors: Bernasconi P. , Rausch T. , Gogarten J.P. , Taiz L.
Published: July 2002

An 800 bp fragment of Methanococcus thermolithotrophicus genomic DNA was amplified by the polymerase chain reaction method using primers designed from conserved regions of the V‐type H+ ATPase regulatory subunits from the archaebacterium Sulfolobus, and several eukaryotes. Although more than one product was obtained, only one of them had the expected size and was exclusively amplified in the presence of the left and right primers. The DNA and the deduced protein sequences of the putative Methanococcus H+ ATPase subunit revealed homology to the corresponding sequences in Sulfolobus and eukaryotes (about 60% identical residues) and a less evident homology to the eubacterial F1 ‐ATPase α‐subunit (22% identical residues with E. coli).
Orientation of the carboxyl terminus of the Na+/proline symport carrier in Escherichia coll
Authors: Komeiji Yuto , Hanada Kentaro , Yamato Ichiro , Anraku Yasuhiro
Published: July 2002

Proline carrier, orientation; Carboxyl terminus; Fusion protein, PutP‐LacZ; Antibody, site‐directed; ELISA, competitive
Molecular cloning of cDNA for cholesterol 7α‐hydroxylase from rat liver microsomes
Authors: Noshiro Mitsuhide , Nishimoto Masazumi , Morohashi Ken-ichirou , Okuda Kyuichiro
Published: July 2002

Cholesterol 7α‐hydroxylase; Cytochrome P‐450; cDNA cloning; (COS cell)
A 1H NMR study of bovine cytochrome oxidase
Authors: Rigby Stephen E.J. , Alleyne Trevor A. , Wilson Michael T. , Moore Geoffrey R.
Published: July 2002

NMR; Cytochrome oxidase; Monoamine, subunit depleted.
Fatty acid acylation of membrane skeletal proteins in human erythrocytes
Authors: Maretzki Dieter , Mariani Mariagabriella , Lutz Hans U.
Published: July 2002

Fatty acid acylation of membrane proteins was studied on human erythrocytes by measuring incorporation of [3H]palmitate at different specific radioactivities. A 55 kDa polypeptide within the band 4.5 region was the main acceptor protein for acylation by fatty acids (palmitate, stearate, oleate), while other polypeptides (80,65,48, 30 kDa) incorporated [3H]palmitate slowly, in substoichiometric amounts. Integral membrane proteins were preferentially fatty acid acylated. Skeletal membrane proteins were, however, poorly labeled. Neither purified ankyrin nor band 4.1 protein were fatty acid aeylated in human erythrocytes. On the other hand, label associated with high molecular weight skeletal proteins resisted low and high ionic strength extractions, and was extracted selectively by uran along with a small subpopulation of spectrin which was also tightly associated with the membrane.
Substitution of aspartic acid‐217 of Citrobacter freundii cephalosporinase and properties of the mutant enzymes
Authors: Tsukamoto Kikuo , Kikura Run , Ohno Reiko , Sawai Tetsuo
Published: July 2002

On the assumption that Asp‐217 of a Citrobacter freundii cephalosporinase forms a salt‐bridge with the conserved Lys‐67, Asp‐217 was changed to glutamic acid, threonine or lysine. The mutant enzymes retained about the same level of activity as that of the wild‐type enzyme, and the participation of Asp‐217 in the salt‐bridge was ruled out. However, the mutations resulted in an increase in hydrolytic activity toward oxyimino‐cephalosporins such as cefuroxime, cefmenoxime and ceftazidime, suggesting a possible mechanism of the bacterial resistance to the novel β‐lactams by a single mutation in cephalosporinases.
Cerebellar granule cells in culture exhibit a ganglioside‐sialidase presumably linked to the plasma membrane
Authors: Riboni Laura , Prinetti Alessandro , Bassi Rosaria , Tettamanti Guido
Published: July 2002

Cerebellar granule cells differentiated in culture were incubated with ganglioside [3H‐Sph]GDla in order to have it inserted into the plasma membrane, internalized by endocytosis, and metabolized. The metabolites formed included GMI. product of GDla desialosylation. No GMI or other metabolites were present in the incubation medium, whereas with the lysosomal apparatus blocked by chloroquine. or GDI a endocytosis prevented at 4° C, the only metabolite formed was GMI. These results suggest that GDI a desialosylation did not occur either extracellularly or intracellularly but likely, at the membrane level. Similar results were obtained with [3H‐Gal]GDlb. whereas no degradation of [3H‐NeuAc]GMI took place in the presence of chloroquine or at 4°C. In conclusion, cerebellar granule cells express in vivo a sialidasc, presumably located on the cell surface. that affects GDIa and GDIb but not GMI.
Light‐induced, long‐lived perturbation of the photocycle of bacteriorhodopsin
Authors: Tokaji Zsolt , Dancsházy Zsolt
Published: July 2002

The relative weight of the slowly decaying M intermediate of the photocycle of bacteriorhodopsin increases upon increasing the energy density of the short (10 ns) actinic laser pulse. Moreover, when a pre‐exciting flash is applied to the BR sample, the absolute amplitude of the Ms is higher in the signal induced by a second flash, applied with a delay from 100 μs to 100 ms. These facts together prove that either the leftover BR ground‐state population becomes different due to the pre‐excitation, or there is a cooperative interaction between the BR molecules.
Electrochemical redox titration of cofactors in the reaction center from Rhodobacter sphaeroides
Authors: Moss D.A. , Leonhard M. , Bauscher M. , Mäntele W.
Published: July 2002

The electrochemical redox poising of the primary electron donor P and of the quinone electron acceptor(s) Q in isolated reaction centers from Rhodobacter sphaeroides in an ultra‐thin‐layer electrochemical cell, monitored by chronoamperometry and by spectroscopy in the visible/near‐infrared region, is reported. Electrical application of a redox potential of +0.4 V (vs. Ag/AgCl/3 M KCl) leads to quantitative formation of the π‐cation radical of P within a few minutes. The oxidized product can be re‐reduced to the neutral species by application of 0 V, and full reversibility is maintained over many‐cycles. By poising at a series of intermediate potentials, a titration curve for the 865 nm P band was obtained, which could be fitted to a Nernst function with E
m = 0.485 vs. SHE and n = 0.96. By Application of negative potentials (−0.2 V and −0.45 V vs. Ag/AgCl/3 M KCl), the quinone electron acceptors were reversibly reduced as demonstrated by the shift of bacteriopheophytin absorption and drastically changed kinetics of charge recombination. The use of this thin‐layer electrochemical technique for the determination of midpoint potentials, for the investigation of redox‐poised electron transfer reactions as well as for spectroscopy in the mid‐infrared region is discussed.
Oligosaccharide‐binding molecules on the surface of human hemopoietic and lymphoid cells
Authors: Abramenko I.V. , Gluzman D.F. , Korchagina E.Yu. , Zemlyanukhina T.V. , Bovin N.V.
Published: July 2002

High oligosaccharide specificity for binding carbohydrate probes (biotinylated polyacrylamide with carbohydrates attached) with human hemopoietic and lymphoid cells is shown. Of 15 probes studied those bearing blood group trisaccharides, A and B, bound most intensely. In addition, transformed (leukemic and lymphoid) cells interacted more strongly than normal ones.
Evidence for a phosphorylation‐induced conformational change in phospholamban cytoplasmic domain by CD analysis
Authors: Terzi Evelyne , Poteur Livia , Trifilieff Elisabeth
Published: July 2002

Phospholamban (PLB), an integral membrane protein of cardiac sarcoplasmic reticulum (SR), is described as the regulator of the Ca2+‐ATPase pump, via its phosphorylation‐dephosphorylation of Ser‐16. Recently it has been shown that a direct interaction between the N‐terminal hydrophilic domain of PLB and Ca2+‐ATPase may be one of the mechanisms of regulation. In order to show that this interaction could be modulated by a phosphorylation‐induced conformational change in PLB, we ran CD studies on the synthetic peptide PLB(2‐33) in its phosphorilated and non‐phosphorylated forms, at various pHs, concentrations and in the absence or presence of trifluoroethanol. The results show a clear difference in structure of the phosphorylated and non‐phosphorylated peptide.
Transfer of a chloroplast‐bound precursor protein into the translocation apparatus is impaired after phospholipase C treatment
Authors: Kerber Birgit , Soll Jürgen
Published: July 2002

We have studied the influence of phospholipase C treatment of intact purified chloroplast on the translocation of a plastid destined precursor protein. Under standard import conditions, i.e. in the light in the presence or 2 mM ATP translocation was completely abolished but binding was observed at slightly elevated levels. An experimental regime which allowed binding but not import of the precursor protein, i.e. in the dark in the presence of 10 μM ATP, demonstrated that translocation intermediates, normally detected at this stage, were missing in phospholipase treated chloroplasts. The precursor was completely sensitive to protease treatment, indicating that the transfer of the precursor from the receptor to the import apparatus was blocked by phospholipase treatment.
Transforming growth factors type‐β and dexamethasone attenuate group II phospholipase A2 gene expression by interleukin‐1 and forskolin in rat mesangial cells
Authors: Mühl Heiko , Geiger Thomas , Pignat Werner , Märki Fritz , van den Bosch Henk , Cerletti Nico , Cox David , McMaster Garry , Vosbeck Klaus , Pfeilschifter Josef
Published: July 2002

Treatment of rat mesangial cells with interleukin‐1β(IL‐1β) and forskolin induced, in a synergistic fashion,the expression of group II phospholipase A2 (PLA2) mRNA, with subsequent increased synthesis and secretion of PLA2. In contrast, interleukin‐6 did not increase PLA2 mRNA levels of PLA2 activity. Transforming growth factor (TGF) β1, TGFβ2 and TGFβ3 equipotently attenuated the IL‐1β‐ and forskolin‐induced elevation of PLA2 mRNA, as well as PLA2 synthesis and secretion. The glucocorticoid dexamethasone only partially suppressed the IL‐1β‐ and forskolin‐induced elevation of PLA2 mRNA, but totally inhibited PLA2 synthesis and secretion.
Nitric oxide‐releasing compounds inhibit Dictyostelium discoideum aggregation without altering cGMP production
Authors: Tao Yongping , Howlett Allyn , Klein Claudette
Published: July 2002

The effects of nitric oxide‐releasing compounds on Dictyostelium discoideum cell development and guanylyl cyclase activity were studied. The addition of SNP (sodium nitroprusside) or SIN‐1 (3‐morpholino‐syndnonimine) to starved cells inhibited their differentiation and aggregation in a concentration‐dependent manner. In contrast to mammalian systems, SNP did not significantly affect guanylyl cyclase activity in cell lysates of D. discoideum nor did it stimulate cGMP production in intact cells. The results suggest that the inhibitory effects of NO on D. discoideum cell aggregation are through a mechanism independent of an effect on guanylyl cyclase activity.
Triple helix formation at A8XA8·T8YT8
Authors: Chandler Simon P. , Fox Keith R.
Published: July 2002

We have examined the formation of DNA triple helices between the oligonucleotides T8XT8 (X = A,C,G,T) and DNA fragments containing the target sequences A8XA8 · T8YT8 (X = T,C,G; Y=A,G,C), by DNase I footprinting. We find that A8GAg8 · T8CT8 yields a footprint with T8CT8 and shows a weaker interaction with T17 and T8GT8· A8CA8 · T8GT8 yields a footprint with T17, and shows weaker interaction with T8CT8. A8TA8 · T8AT8 yields a footprint with T8GT8 and shows weaker interaction with T17. Each of the successful complexes is characterised by enhanced DNase I cleavage at the 3' end of the purine strand of the target, as well as protection at the 5' end. We have been unable to form triplexes with third strands of the type A8XA8.
Localization of a fibrin polymerization site complementary to Gly‐His‐Arg sequence
Authors: Medved L.V. , Litvinovich S.V. , Ugarova T.P. , Lukinova N.I. , Kalikhevich V.N. , Ardemasova Z.A.
Published: July 2002

Dansyl‐labeled tetrapeptide Gly‐His‐Arg‐Pro which mimics the central fibrin polymerization site was used to investigate its binding to a number of fibrinogen fragments containing different numbers of domains. The tetrapeptide was found to bind to fragments DH(95 kDa), DL(82 kDa) and DY(63 kDa) but not to the TSD(28 kDa) fragment. The DY fragment differs from the TSD by the presence of β and βC domains. Therefore these domains, which are formed by the C‐terminal part of the β chain, possess a polymerization site complementary to the Gly‐His‐Arg containing counterpart.
Methylglyoxal and the polyol pathway
Authors: Lindstad Rune I. , McKinley-McKee John S.
Published: July 2002

Methylglyoxal, 1,2‐propanediol and glycerol are shown to be substrates for sheep liver sorbitol dehydrogenase. With 1,2‐propanediol the enzymecatalyzed reaction occurs specifically with the R(−)‐enantiomer. The maximum velocities and the specificity constants obtained for the three‐carbon substrates are considerably lower than those reported previously for sorbitol, and suggest that rate‐determination is imposed by catalytic steps other than the enzyme‐coenzyme product dissociation. The present findings are discussed in terms of substrate specificity and stereospecificity, and may indicate novel aspects of sorbitol dehydrogenase function in relation to glucose metabolism and diabetic pathogenesis.
Localization of an O‐glycosylation site in the α‐subunit of the human platelet integrin GPIIb/IIIa involved in Baka (HPA‐3a) alloantigen expression
Authors: Calvete Juan J. , Muñiz-Diaz Eduardo
Published: July 2002

The human alloantigen system Bak a/b is associated with a Ile 843→ Ser replacement on platelet glycoprotein IIb, the α‐subunit of the integrin receptor for fibrinogen (GPIIb/IIIa). Recent immunological studies indicate that sialylated oligosaccharide chain(s) are also implicated in expression of the Baka determinant. Here we show that the GPIIb fragment 704–856 contains the whole Bak a epitope, and that chemical cleavage of a single O‐linked oligosaccharide chain within this GPIIb domain correlates with the loss of its anti‐Baka antibodies binding ability. Ser847 was identified as the O‐glycosylation site. Therefore, our results show that the Ser847 modification is responsible for the expression of the GPIIb‐specific Baka alloantigen, and provide thus a link between the molecular biology and the immunologie observations.
Mechanism of pH‐induced release of retinol from retinol‐binding protein
Authors: Ptitsyn O.B. , Zanotti G. , Denesyuk A.L. , Bychkova V.E.
Published: July 2002

A hypothesis is proposed explaining the mechanism of pH‐induced release of retinol from retinol‐binding protein (RBP). A number of conservative positively charged side chains located on the retinol‐binding face of the RBP molecule are involved in salt bridges with conservative negatively charged groups. At low pH these salt bridges are broken and the retinol‐binding face of RBP holds from 8 to 12 positively charged groups, which can ensure a proper orientation of the RBP molecule relative to a negatively charged membrane, facilitating the release of retinol. The disruption of salt bridges and the electrostatic repulsion of positive charges can soften the structure of the molecule near the entrance to the retinol‐binding pocket, which can trigger both the release of retinol and the transition of RBP to the molten globule state.
The conformational analysis of a synthetic S4 peptide corresponding to a voltage‐gated potassium ion channel protein
Authors: Haris Parvez I. , Ramesh Bala , Brazier Stephen , Chapman Dennis
Published: July 2002

The S4 region of the Drosophila Shaker voltage‐gated K+ channel has been proposed to function as a voltage‐sensor. We have synthesised a peptide corresponding to this S4 region. Structural studies on the S4 peptide were conducted using Fourier transform infrared (FTIR) spectroscopy. Spectra were obtained for the peptide dissolved in aqueous solution, in trifluoroethanol solvent and also after reconstitution into lipid bilayers and micelles. The peptide in trifluoroethanol adopts an α‐helical conformation which is in good agreement with the results of a recent 2D NMR study on the structure of a S4 peptide corresponding to the rat brain sodium channel [(1989) FEBS Lett. 257, 113‐1171. A predominantly α‐helical structure is also observed when the S4 peptide is present in aqueous lysophosphatidylcholine micelles, in dimyristoyl phosphatidylcholine and dimyristoyl phosphatidylglycerol lipid bilayers. In contrast to this, the S4 peptide in aqueous solution is in a random coil conformation. The coil‐to‐helix transition observed for the S4 peptide upon its transfer from aqueous solution to lipid membrane indicates that it has a high degree of conformational flexibility and can undergo large changes in its structure in response to its environment. This may have important implications for its role in the voltage activation process during which the S4 peptide has been postulated to, at least partially, move from a lipid bilayer to an aqueous extracellular media [(1992) Biophys J. 62, 238 250]. The results of our study lend support to such a model.
Purification and characterization of a novel tripeptidyl aminopeptidase from Streptomyces lividans 66
Authors: Krieger Timothy J. , Bartfeld Daniel , Jenish David L. , Hadary Dany
Published: July 2002

An extracellular tripeptidyl aminopeptidase has been purified from Streptomyces lividans 66 cell‐free cultures. The enzyme is a major component of the secreted proteolytic activity. The protease removes only the N‐terminal tripeptide from recombinant human GM‐CSF and IL‐3 but does not cleave recombinant human IL‐6. The enzyme cleaves the synthetic tripeptide substrates APA‐pNA and APM‐pNA but does not cleave substrates with blocked amino terminals. Smaller substrates are not cleaved. The enzyme appears to be a serine protease of 55 kDa molecular weight. The pH optimum is between 7.5 and 8.5 but varies slightly with the substrate. The N‐terminal sequence and amino acid composition have been determined.