bluuebunny/crossref_metadata_2025 huggingface dataset:
Monovalent cation‐dependent reversible phosphorylation of a 40 S ribosomal subunit protein in growth‐arrested Tetrahymena: correlation with changes in intracellular pH
Authors: Goumard Geneviève , Cuny Marguerite , Sripati Conjeevaram E. , Hayes Donal H.
Published: July 2002

Phosphorylation and dephosphorylation of ribosomal protein S8 in starved Tetrahymena induced respectively by Na+ and K+ are accompanied by changes in intracellular pH which rises by about 0.8 pH units in cells starving in the presence of Na+ (phosphorylation of S8) and falls by a little more than one pH unit after subsequent addition of K+ (dephosphorylation of S8).
The role of phospholipase A2 in lipid peroxidation‐induced fall of membrane potential of rat liver mitochondria
Authors: Gogvadze V.G. , Brustovetsky N.N. , Zhukova A.A.
Published: July 2002

Cumene hydroperoxide (230 μM)‐induced fall of the membrane potential takes place only in Ca2+ ‐loaded mitochondria. Inhibitor of phospholipase A2, P‐bromphenacyl bromide prevents uncoupling of mitochondria, having no effect on the accumulation of lipid peroxidation products.
Bacterial ferritin contains 24 haem groups
Authors: Kadir Fahmi H.A. , Moore Geoffrey R.
Published: July 2002

Pseudomonas aeruginosa bacterioferritin, also known as cytochrome b
1 or cytochrome b
557, has been isolated with 9 haems per 24 subunits. Various forms of the protein have been prepared including the completely haem‐free protein and the fully haem‐loaded protein with 24 haems per 24 subunits. The presence of the core does not significantly affect haem addition or removal. The absorbance ratio of the non‐haem‐iron‐loaded protein, 278 nm:417 nm (oxidised), can be used to estimate the haem loading.
Phosphatidylinositol 4,5‐bisphosphate stimulates protein kinaseC‐mediated phosphorylation of soluble brain proteins
Authors: Chauhan Ved P.S.
Published: July 2002

Phosphatidylinositol 4,5‐bisphosphate (PIP2) at 0.1 mol% activated the protein kinase C (PKC)‐mediated phosphorylation of 87‐, 55‐ and 47‐kDa brain proteins. Neomycin, an aminoglycoside antibiotic that binds PIP2 with a high affinity, inhibited PIP2·PKC activity in a concentration‐dependent manner. Low concentrations of neomycin (< 2 mM) did not affect DG·PKC activity; however, 4 mM neomycin inhibited 50% of this activity. This inhibition of DG‐stimulated activity at high neomycin concentration may be the result of its binding to Ca2+ and ATP in the assay system. These results suggest that PIP2 is a physiological activator of PKC, and show that neomycin can be an inhibitor of PIP2·PKC activity at concentrations where DG·PKC activity is not affected.
Human neurochordins: identification of several P‐epitope‐bearing polypeptides and a study of their ontogenetic expression
Authors: Preobrazhensky A.A. , Rodionova A.I. , Yaroshevich E.Yu. , Feshenko S.P.
Published: July 2002

Neurochordins are a family of immunologically related high‐M
r neural tissue glycoproteins. After SDS‐agarose electrophoresis of human neural tissue extracts, two main neurochordins (A1 and B2) as well as several minor ones (O, A2, A3, B1, B3, C1, C2, D) were vizualized on immunoblots stained with monoclonal antibody At5. Neurochordin expression starts in human embryos before 6 weeks of gestation. General antigenic activity of neurochordins increases between 6 and 24 weeks of gestation while its level does not alter from the second half of gestation up to the age of 11–13 years. Neurochordins extracted from large hemispheres of brain, from cerebellum and spinal cord of a 24‐week embryo display a similar pattern after electrophoresis. Partially different pattern of neurochordins was observed with a brain tumor.
Serine phosphorylation of biosynthetic pro‐urokinase from human tumor cells
Authors: Mastronicola M.Rosaria , Stoppelli M.Patrizia , Migliaccio Antimo , Auricchio Ferdinando , Blasi Francesco
Published: July 2002

Phosphorylation is a potent mechanism regulating the activity of many intracellular enzymes. We have discovered that the product of the human urokinase plasminogen activator gene, pro‐uPA, is phosphorylated in serine in at least two human cell lines. Phosphorylation occurs within the cell during biosynthesis, and phosphorylated intracellular pro‐uPA is secreted into the medium. Of the secreted pro‐uPA molecules, 20–50% are phosphorylated in serine, thus representing a meaningful fraction of the total biosynthetic pro‐uPA. Although the sites of phosphorylation have not yet been determined, at least two such sites must exist; in fact plasmin cleavage of phosphorylated single chain pro‐uPA yields a two chain uPA in which both chains are phosphorylated. A specific function for pro‐uPA phosphorylation has not yet been identified; however, it is tempting to speculate that, as in many other cases, phosphorylation may affect the activity of the enzyme, its response to inhibitors or the conversion of pro‐uPA zymogen to active two‐chain uPA. This would represent an additional way of regulating extracellular proteolysis, an important pathway involved in both intra‐ and extravascular phenomena like fibrinolysis, cell migration and invasiveness.
The dynamics of the expression of C/EBP mRNA in the adult rat liver lobulus qualifies it as a pericentral mRNA
Authors: Moorman Antoon F.M. , van den Hoff Maurice J.B. , de Boer Piet A.J. , Charles Robert , Lamers Wouter H.
Published: July 2002

A hybridocytochemical approach has been applied to establish whether the gene for the C/EBP mRNA might be involved in the topographical regulation of gene expression in adult rat liver. To that end the spatial distribution of the mRNA of C/EBP has been compared to that of the mRNAs of glutamine synthetase (GS), phosphoenolpyruvate carboxykinase (PEPCK) and glucokinase (GK) in normal adult livers, in livers from dcxamethasone‐treated animals and in livers from starved animals refed with glucose for 4 h. In normal rat liver, in situ hybridization with a probe for C/EBP mRNA revealed a low density of apparently homogeneously distributed grains, indicating low levels of C/EBP mRNA. In contrast, the livers of the experimentally‐treated animals revealed a zonal distribution of the mRNA of C/EBP with the highest density of grains around the central venules. The dynamics of the pattern of expression of C/EBP mRNA are virtually identical to that of the GK mRNA. These data qualify C/EBP mRNA as a pericentral mRNA and suggest a role for the C/EBP protein in the topographical regulation of the expression of the GK mRNA.
Genomic structure of human lysosomal glycosylasparaginase
Authors: Park Hyejeong , Fisher Krishna J. , Aronson Nathan N.
Published: July 2002

The gene structure of the human lysosomal enzyme glycosylasparaginase was determined. The gene spans 13 kb and consists of 9 exons. Both 5′ and 3′ untranslated regions of the gene are uninterrupted by introns. A number of transcriptional elements were identified in the 5′ upstream sequence that includes two putative CAAT boxes followed by TATA‐like sequences together with two AP‐2 binding sites and one for Sp1. A 100 bp CpG island and several ETF binding sites were also found. Additional AP‐2 and Sp1 binding sites are present in the first intron. Two polyadenylation sites are present and appear to be functional. The major known glycosylasparaginase gene defect G488→C, which causes the lysosomal storage disease aspartylglycosaminuria (AGU) in Finland, is located in exon 4. Exon 5 encodes the post‐translational cleavage site for the formation of the mature α/β subunits of the enzyme as well as a recently proposed active site threonine, Thr206.
Molecular cloning and sequence analysis of cDNA and genomic DNA for the human cone transducin α subunit
Authors: Kubo Mitsumasa , Hirano Teiichi , Kakinuma Mitsuaki
Published: July 2002

A novel GTP binding protein (G protein) α subunit cDNA was isolated from a T cell leukemia cell line, Jurkat, utilizing polymerase chain reaction (PCR). The predicted amino acid sequence of this G protein α subunit showed the highest identity (96.6%) to bovine cone cell‐specific transducin (Tcα). The organization of the coding region of this G protein α subunit gene was composed of 8 exons and 7 introns. Northern hybridization revealed the presence of this G protein message in a retinoblastoma cell line, Y79. In Jurkat, however, the message was detectable only by reverse transcription/PCR. Taken together, this novel G protein α subunit must be human Tc.
Changes in the expression of mRNAs for myogenic factors and other muscle‐specific proteins in experimental autoimmune myasthenia gravis
Authors: Asher Orna , Fuchs Sara , Zuk Dorit , Rapaport Debora , Buonanno Andres
Published: July 2002

The regulation of genes for acetylcholine receptor (AChR), myogenic factors and other muscle‐specific proteins has been analyzed in experimental autoimmune myasthenia gravis (EAMG) and following denervation. The levels of the transcripts for the myogenic factors, MyoDl, myogenin and MRF4, were measured using Northern blot analysis. Myogenin and MRF4 transcript levels were observed to be 3.1 ‐ and 2.6‐fold higher in muscle of rats with EAMG than in controls, respectively. MyoDl levels, however, remained unchanged. The increases in AChR, myogenin and MRF4 mRNAs were one order of magnitude higher in 2‐week denervated muscle than in the myasthenic muscle. The levels of muscle creatine kinase (MCK), α‐actin and muscle dystrophin transcripts were also analyzed. Dystrophin levels were found to be 1.7‐ and 4.7‐fold higher in EAMG and denervated muscle, respectively, than in controls; in contrast, MCK and α‐actin levels remained unchanged.
On how hydrolysis at the 3′ end is prevented in the splicing of a sequentially folded group I intron
Authors: Fernández Ariel
Published: July 2002

We propose a dynamic model for the competition between exon—exon ligation and 3′‐end hydrolysis valid for sequentially folded pre‐mRNA introns of group I. This model accounts for the delay in the formation of conserved helix P10 until the 5′ exon has been cleaved, a requirement to prevent hydrolysis at the 3′ end of the intron. The model is rooted on computer simulations whereby the pre‐mRNA searches for its structure as it is being transcribed. Thus, a competing interaction, engaging the internal guiding sequence, occurs initially and prevents P10 from forming until the 3′ end of the 5′ exon is habilitated as a nucleophilic agent. It is further shown that a destabilization of the competing interaction invariably leads to 3′ hydrolysis, crippling the splicing capability of the intron. The results may be probed by site‐directed mutagenesis.
Identification of a membrane‐associated 1‐0‐alkyl‐2‐arachidonoyl‐sn‐glycero‐3‐phosphocholine hydrolyzing phospholipase A2in guinea pig 1 epidermis Implications in the cutaneous biosynthesis of platelet‐activating factor
Authors: Wong Barnett , Tang Wilson , Ziboh Vincent A.
Published: July 2002

A membrane‐associated 1‐0‐alkyl‐2‐arachidonoyl‐GPC hydrolyzing phospholipase A2 was identified in guinea pig epidermis. It is regio‐speciflc (associated with the particulate microsomal fraction) and specific for the hydrolysis of 1‐0‐alkyl‐2‐arachidonoyl‐sn‐glycero‐3‐phosphocholine. It is sensitive to low calcium concentrations suggesting that it may be activated by increasirg intracellular calcium. Since ether‐linked phospholipids are known to exist in the epidermis, further understanding of the properties of this 1‐0‐alkyl‐arachidonoyl‐hydrolyzing PLA2 may allow us to control the generation of 1‐0‐alkyl‐2‐lyso‐sn‐glycero‐3‐phosphocholine, a key substrate for the generation or the platelet‐activating factor in the tissue.
How is rat liver S‐adenosylmethionine synthetase regulated?
Authors: Pajares Maria A. , Corrales Fernando , Durán Cristina , Mato José M. , Alvarez Luis
Published: July 2002

The in vivo regulation of S‐adenosylmethionine synthetase, a key enzyme in methionine metabolism, is so far unknown. The enzyme activity has been shown to be modulated by glutathione and the oxidation state of its sulfhydryl groups. Analysis of the protein sequence has revealed the presence of putative phosphorylation sites. A mixed regulatory mechanism combining phosphorylation and the oxido/reduction of sulfhydryl groups is proposed. The role of glutathione in this mechanism is also discussed.
Prothymosin α is phosphorylated by casein kinase‐2
Authors: Barcia Miguel G. , Castro José M. , Jullien Cristina D. , González Carlos G. , Freire Manuel
Published: July 2002

Prothymosin α (ProTα) is a 12.5 kDa acidic polypeptide that is considered to have a nuclear function related to cell proliferation. Inspection of its amino acid sequence revealed the presence of sequences that may serve as targets for phosphorylation by casein kinase‐2 (CK‐2). ProTα isolated from calf thymocytes was phosphorylated in vitro by CK‐2. The phosphorylation sites are Ser and Thr residues located among the first 14 amino acid residues in the ProTα sequence. Another site that is theoretically suitable for phosphorylation by CK‐2, at the C‐terminus of the polypeptide, is not, in fact, phosphorylated. Thymosin α1 (Tα1), a peptide whose sequence corresponds to the first 28 amino acids of ProTα, is also phosphorylated by CK‐2 at the same phosphorylation sites as ProTα. In cultured splenic lymphocytes ProTα was phosphorylated at Thr residues located at positions 7, 12 and/or 13. Based on these observations we conclude that CK‐2, or another cellular kinase with similar sequence specifity, is responsible for phosphorylation of ProTα in vivo.
Expression cloning of a sheep adreno‐ferredoxin using the polymerase chain reaction
Authors: Matsuo Yoshinori , Tsujita Maki , Mizoguchi Kazuhiro , Ichikawa Yoshiyuki
Published: July 2002

In addition to the selective amplification of cDNA from total RNA by the PCR method, the distinctive properties of ferredoxin‐expressing colonies can be used for cloning a ferredoxin cDNA. This strategy for cloning and expressing cDNA in E. coli was applied to a sheep adreno‐ferredoxin. The expressed sheep ferredoxin showed a spectral pattern typical or [2Fe‐2S] proteins. The amino acid sequence deduced from the DNA sequence showed that the mature form of sheep ferredoxin consists of 128 amino acid residues. This rapid and simple method for cloning and expressing cDNA can be applied to other ferredoxins.
Enzymatic and immunological detection of G protein α‐subunits in the pathogenic fungus Candida albicans
Authors: Paveto Cristina , Montero Lilian , Passeron Susana
Published: July 2002

GTP stimulation of adenylyl cyclase from the dimorphic pathogenic fungus Candida albicans is greatly enhanced by preincubation of membrane proteins with cholera toxin, NAD and ATP. In the presence of [32P]NAD the toxin catalyzes the covalent incorporation of radioactivity into a menbrane protein of 40 kDa. Pertussis toxin catalyzes the transference of the radioactivity from [32P]NAD to a 32 kDa protein. Two major proteins of 40–42 and 30–32 kDa can also be recognized in Western blots by an anti Gα‐common antibody. The results support the idea that G proteins are part of the hormonesensory transduction chain of Candida [(1990) Biochem. Biophys. Res. Commun. 167. 1177‐1183].
Identification of a novel high‐affinity binding site for N‐acetylchitooligosaccharide elicitor in the membrane fraction from suspension‐cultured rice cells
Authors: Shibuya Naoto , Kaku Hanae , Kuchitsu Kazuyuki , Maliarik Mary J.
Published: July 2002

Binding experiments using a 125I‐labeled tyramine conjugate of N‐acetylchitooctaose, a highly potent elicitor for the induction of phytoalexin production in rice cells, and a microsomal membrane preparation from suspension‐cultured rice cells showed the presence of a novel high‐affinity binding site for this oligosaccharide. The binding of the ligand was saturable and the Scatchard plot analysis of the results indicated the presence of a single class of binding site with a K
d of 5.4 nM which is comparable with that reported for the binding of the hepta‐β‐glucoside elicitor in soybean membrane. The ligand binding was inhibited by unlabeled N‐acetylchitoheptaose but not by its deacetylated form. These characteristics of this binding site coincide well with the specificity and sensitivity for the elicitor in several assay systems, suggesting the possible involvement of this binding site in the recognition of the elicitor in vivo.
Increased anti‐HIV‐1 activity of CD4 CDR3‐related synthetic peptides by scrambling and further structural modifications, including d‐isomerization and dimerization
Authors: Kumagai Kazuo , Tokunaga Kenzo , Tsutsumi Masahiro , Ikuta Kazuyoshi
Published: July 2002

We recently showed that S1, a sequence‐scrambled form of CD4 CDR3‐related synthetic peptide, has more potent inhibitory activities on HIV‐1 replication and HIV‐1‐induced syncytium formation than the original form. In this study, a series of derivatives of S1 were synthesized and their anti‐HIV‐1 activities were evaluated. A d‐isomer was as potent as S1, and a homodimer was 10‐ to 18‐fold more potent than S1. The increased antiviral activity of the dimer peptide was related to α‐helix formation, as detected by circular dichroism.
Trimeric mutant bacteriorhodopsin, D85N, shows a monophasic CD spectrum
Authors: Kataoka Mikio , Mihara Ken'ichi , Kamikubo Hironari , Needleman Richard , Lanyi Janos K. , Tokunaga Fumio
Published: July 2002

The structure of mutant bacteriorhodopsin (bR), D85N, was examined by CD and X‐ray diffraction at pH 7. The absorption maximum of D85N at pH 7 is located at 605 nm, which is similar to the acid‐blue form of wild‐type bR. D85N shows a monophasic CD band, the maximum of which is at 575 nm, although the crystalline arrangement and the trimeric structure is maintained. The acid‐blue form of wild‐type bR shows a biphasic CD despite the similarity in absorption spectra.
Reaction of the type III iodothyronine deiodinase with the affinity label N‐bromoacetyl‐triiodothyronine
Authors: Schoenmakers Christian H.H. , Pigmans Ingrid G.A.J. , Kaptein Ellen , Darras Veerle M. , Visser Theo J.
Published: July 2002

The type III iodothyronine deiodinase (ID‐III) catalyzes the inner ring deiodination and, thus, the inactivation of the thyroid hormones T4 and T3. ID‐III activity in rat brain, rat placenta and embryonic chicken liver is inhibited by the affinity label N‐bromoacetyl‐T3, (BrAcT3) with an affinity similar to that of T3. Reaction of rat brain and placenta microsomes with BrAc[125I]T3 resulted in the extensive labeling of a 32 kDa protein (p32). However, p32 was also prominently labeled in fetal rat liver microsomes which have no ID‐III activity. Labeling of p32 was not influenced by 100 μM substrate analogs or inhibitors of ID‐III, some of which completely inhibit ID‐III activity at 1 μ. BrAc[125I]T3, labeling of embryonic chicken liver microsomes did not reveal p32 or another protein possibly related to ID‐III. In contrast to previous suggestions, it is unlikely that p32 represents ID‐III or a subunit thereof.
α‐Latrotoxin‐stimulated GABA release can occur in Ca2+‐free, Na+‐free medium
Authors: Storchak L.G. , Pashkov V.N. , Pozdnyakova N.G. , Himmelreich N.H. , Grishin E.V.
Published: July 2002

We have studied [14C]GABA release from synaptosomes induced by native and monoclonal antibodies‐modified α‐latrotoxin (LTX). Modification of LTX eliminates the toxin's ability to increase [Ca2+]i influx into synaptosomes. It has been shown that native LTX does not change 22Na influx into rat brain synaptosomes. Both toxin forms studied, native and modified by monoclonal antibodies, stimulate [14C]GABA release from synaptosomes in divalent‐free medium where sodium was substituted by equimolar concentrations of choline chloride. Native toxin induces a more rapid stimulation of [14C]GABA release than the modified one. It was suggested that the difference in the mediator release rates is not accounted for by the inability of modified toxin to form active ion channels in synaptosomal plasmalemma, but most probably by the state of toxin‐receptor complexes.
Effect of ethoxyformic anhydride on the Rieske iron—sulfur protein of bovine heart ubiquinol: Cytochrome c oxidoreductase
Authors: Ohnishi T. , Meinhardt S.W. , von Jagow G. , Yagi T. , Hatefi Y.
Published: July 2002

Treatment of bovine heart ubiquinol‐cytochrome c oxidoreductase (complex III, bc
1 complex) with ethoxyformic anhydride (EFA) inhibits electron transfer between cytochromes b and c
1 [Yagi et al., Biochemistry 21 (1982) 4777–4782]. This paper shows that EFA alters the EPR lineshape of the Rieske iron—sulfur cluster in complex III and in the isolated Rieske protein without a significant decrease of spin concentration. The effect of EFA on the Rieske iron—sulfur cluster is competitive with that of Qo site inhibitors, such as stigmatellin, and is completely reversed by hydroxylamine. These results are consistent with the possible ethoxyformylation by EFA of histidine ligands of the Rieske iron—sulfur cluster at the non‐iron binding imidazole nitrogens.
Developmental regulation of gene expression for the MPTPδ isoforms in the central nervous system and the immune system
Authors: Mizuno Kazuya , Hasegawa Kiminori , Ogimoto Mami , Katagiri Tatsuo , Yakura Hidetaka
Published: July 2002

MPTPδ is a murine transmembrane protein tyrosine phosphatase which has three isoforms, types A–C, differing in the structure of the extracellular regions. In this study, we examined MPTPδ isoform expression in the brain and the immune system at discrete developmental or differentiation stages. RT‐PCR analysis demonstrated that another isoform, type D, is transcribed from the MPTPδ gene. In the brain, only type D was expressed until postnatal day 7 (P7), but after P14, all four isoforms were detected. In contrast, the spleen, thymus and all the hematopoietic cell lines examined express only types B and C isoforms. An in situ hybridization study showed that MPTPδ mRNA is diffusely expressed throughout the spleen, but its expression in the thymus is restricted to the medullary region.
Low‐temperature magnetic circular dichroism investigation of the active site of chloroperoxidase
Authors: Yarmola Elena G. , Sharonov Yurii A.
Published: July 2002

Magnetic circular dichroism (MCD) spectra for near UV and visible spectral regions of chemically reduced chloroperoxidase from Caldariomyces fumago have been recorded at temperatures from near 293 to 2.15 K. The spectra of reduced chloroperoxidase at 4.2 K were compared with those of photolysis products of its carbon monoxide complexes. Obtained results give evidence for high rigidity of the active site in chloroperoxidase and strongly suggest that thiolate is a protein‐derived ligand of the heme iron in the reduced enzyme. The unusual high‐spin ferrohemoproteins temperature dependence of the Soret MCD closely resembles that of the substrate‐bound cytochrome P‐450cam.
The use of near‐infrared charge‐transfer transitions of low‐spin ferric chlorins in axial ligand assignment
Authors: Peng Qinyun , Peterson Jim
Published: July 2002

The near‐infrared magnetic circular dichroism spectra of some low‐spin derivatives of ferric‐octaethylchlorin substituted myoglobin have been recorded at cryogenic temperatures. The spectra, which include some of the lowest energy charge‐transfer transitions ever observed for hemes, are clearly dependent upon the nature of the axial ligands present. While the results indicate that such spectra may have some practical utility in axial ligand assignment, as is now quite common practice for iron‐porphyrin systems, there are some severe practical limitations to this protocol documented in the case of iron‐chlorins.
Escherichia coli SecY and SecE proteins appear insufficient to constitute the SecA receptor
Authors: Kim Young Jae , Oliver Donald B.
Published: July 2002

In order to test whether SecY and SecE proteins constitute the SecA receptor inside out membrane vesicles where prepared from strains producing greatly different levels of these two proteins, and their SecA binding activity was quantitated. Substantial overproduction of SecE or SecY and SecE proteins resulted in no increase or only 50% increase, respectively, in the number of high affinity SecA binding sites. These results suggest that SecY and SecE proteins appear insufficient to constitute the primary SecA receptor. The existence of a cycle of SecA association with the inner membrane and its modulation by particular integral membrane proteins is discussed.
Pulmonary hypertension, cardiac disease and pregnancy
Authors: Tahir H.
Published: July 2002

Objective: To ascertain the significance of coexisting pulmonary hypertension in cardiac disease in pregnancy. Methods: Over a 3‐year period a group of pregnant women with cardiac disease was followed until 6 weeks postpartum. Twenty women with pulmonary hypertension were compared with 20 controls without pulmonary hypertension with particular reference to maternal and fetal outcome. Analysis of data was carried out using Fisher's exact test and Student's t‐test. Results: Except for Eisenmenger's syndrome, there were no differences in maternal morbidity and mortality between the two groups. There were more low birth weight babies but no significant differences in premature delivery rate, mode of delivery or perinatal mortality. Conclusion: Except for Eisenmenger's syndrome, coexisting pulmonary hypertension complicating cardiac disease in pregnancy generally has a favorable outcome for both mother and fetus.
The S. pombe sep1 gene encodes a nuclear protein that is required for periodic expression of the cdc15 gene
Authors: Zilahi Erika , Salimova Ekaterina , Simanis Viesturs , Sipiczki Matthias
Published: July 2002

The Schizosaccharomyces pombe sep1 gene encodes a putative transcription factor that is required for cell separation. Among the genes required for septum formation and cytokinesis in fission yeast examined to date, the only one whose mRNA fluctuates significantly during the cell cycle is cdc15. In this study we have examined cdc15 mRNA levels in sep1 mutant and null backgrounds and have found that sep1p function is required for periodic accumulation of cdc15 mRNA. We have also localised sep1p and find that it is a nuclear protein, consistent with its proposed role as a transcription factor.
Identification and expression of the motilin precursor in the guinea pig
Authors: Xu Luo , Depoortere Inge , Tang Ming , Peeters Theo L.
Published: July 2002

Motilin has never been isolated from rodents, the most frequently used laboratory animals, despite several attempts. We have isolated and sequenced the motilin precursor from duodenal mucosa of guinea pig (GenBank accession number AF323752) and studied its expression in several tissues. The percent homology with human motilin is the lowest yet observed due to several unique substitutions in the C‐terminal end. As expected, the precursor was present in the gut mucosa with the exception of the gastric corpus. It was also present in medulla oblongata, nucleus of the solitary tract, hypophysis, spinal cord, hypothalamus, and cerebellum but not in the cerebral cortex. For the first time we demonstrated motilin expression in the thyroid.
Genetically engineered mice as animal models for NIDDM
Authors: Joshi Rajiv L , Lamothe Betty , Bucchini Danielle , Jami Jacques
Published: July 2002

Genetically engineered animals carrying defined alterations in their genome can represent invaluable tools for better understanding complex polygenic diseases such as non‐insulin‐dependent diabetes mellitus (NIDDM) at the molecular level. The structure or expression of a number of genes potentially involved in insulin action or pancreatic β‐cell function have recently been altered in the mouse using transgenic or gene‐targeting approaches. The obtention of such mice is the first step towards the development of animal models carrying multiple gene defects which would be very useful in NIDDM research.
Cloning, sequencing and expression of VAT, a CDC48/p97 ATPase homologue from the archaeon Thermoplasma acidophilum
Authors: Pamnani Vashu , Tamura Tomohiro , Lupas Andrei , Peters Jürgen , Cejka Zdenka , Ashraf William , Baumeister Wolfgang
Published: July 2002

© 1997 Federation of European Biochemical Societies.
1H NMR and fluorescence studies of the complexation of DMPG by wheat non‐specific lipid transfer protein. Global fold of the complex
Authors: Sodano Patrick , Caille Anita , Sy Denise , de Person Grégoire , Marion Didier , Ptak Marius
Published: July 2002

Plant non‐specific lipid transfer proteins (LTPs) are proteins which transfer lipids between membranes in vitro and are believed to be involved in the transport of cutin monomers to the cuticle layer in vivo or in the plant defence against phytopathogens. The complexation of DMPG, a diacyl phospholipid, by wheat ns‐LTP, a protein extracted from wheat seeds, was followed by 1H NMR and fluorescence spectroscopy. The global fold of the protein was calculated using the DIANA software package from a list of 968 distance constraints. The internal cavity volume, a feature common to all known ns‐LTP structures, was estimated to be 750 Å3 using the ‘CAVITE’ program. This model of the complex was obtained by inserting a lipid molecule in the cavity and was energy minimized. The study showed that the protein fold described for the free form was only weakly affected by the insertion of the bulky lipid. Observation of some intermolecular NOEs between the protein and the lipid glycerol moiety revealed that the cavity entrance was located between residues His35 and Arg44. The resulting solution structure was compared to the crystal structure of the maize ns‐LTP/palmitate complex.
A cyclic peptide analogue of loop III of PDGF‐BB causes apoptosis in human fibroblasts
Authors: Brennand David M , Scully Michael F , Kakkar Vijay V , Patel Geeta
Published: July 2002

A cyclic peptide analogue of platelet‐derived growth factor‐BB (PDGF‐BB), P1 [77IVRKK81‐C‐73RKIE76], has recently been shown to inhibit specifically [125I]PDGF‐BB/receptor binding, and PDGF‐BB‐induced DNA synthesis in cells expressing PDGF receptors. Here we demonstrate that P1 induces apoptosis in exponentially growing human fibroblasts as confirmed by characteristic changes in cell and nuclear morphology, by TUNEL staining and by flow cytometry. Following incubation with P1 (100 μM), the percentage of cells exhibiting DNA fragmentation increased from 24% after 8 h to 76% after 28 h as exponentially growing cells progressed through the cell cycle. We conclude from these findings taken together that apoptosis accounts for the major proportion of P1‐induced cell death. Omission of the Cys residue from P1 or replacement by Ser did not alter the potency of the peptide confirming that peptide dimerisation is not important for its activity. PDGF‐BB, EGF, FGF, thrombin and foetal bovine serum were not able to rescue cells from the effects of P1. P1 is a useful tool for investigation of the balance of cellular proliferation/apoptosis in wound healing, atherosclerosis and restenosis, and constitutes a basis from which to design compounds with greater potency.
Muscle/heart isoform of mitochondrial adenine nucleotide translocase (ANT1) is transiently expressed during perinatal development in rat liver
Authors: Grado Angels , Manchado Carles , Iglesias Roser , Giralt Marta , Francesc Villarroya  , Mampel Teresa , Viñas Octavi
Published: July 2002

A postnatal increase in the content of mitochondrial ANT in rat liver which is related to the maturation of mitochondrial function has previously been reported [Schönfeld et al., Biochim. Biophys Acta 1144 (1993) 353–358]. In order to define the contribution of the ANT isoforms to this postnatal increase we have studied the expression of ANT1 and ANT2 isoforms in the liver during this period. The results show that in contrast to adult liver, perinatal liver expressed the ANT1 isoform at the mRNA and protein level, and that during this period the expression of ANT1 increased to a similar extent as total ANT content. It is concluded that the postnatal increase in ANT is mainly due to the ANT1 isoform and therefore, a role for the ANT1 isoform in the postnatal maturation of mitochondrial respiration in rat liver is suggested.
An efficient system for site‐directed mutagenesis to make various mutants of the env gene of human immunodeficiency virus type 1
Authors: Shimizu Nobuaki , Hoshino Hiroo
Published: July 2002

We developed an efficient system of site‐directed mutagenesis for the envelope (env) gene of human immunodeficiency virus type 1 (HIV‐1). To make a template plasmid for mutagenesis, pS+B/MluI, two independent selection markers, i.e. a unique restriction site, MluI, and an in‐frame termination codon, were introduced into the region encoding the V3 domain of the env gene of an HIV‐1 strain, NL4‐3, which had been cloned in the pUC118 plasmid. When the env gene of the pS+B/MluI plasmid was mutated successfully using mutagenic primers such as synthetic oligonucleotides or PCR‐amplified DNA fragments longer than 1.5 kbp, the plasmids became resistant to digestion with MluI and competent env genes were formed by suppression of the in‐frame termination. Various site‐directed mutants of the env gene of HIV‐1 were accurately constructed in a short time even in the absence of proper restriction sites by this system. The system of site‐directed mutagenesis we reported here will be a useful method to analyze the functions of variable genes like the env gene of HIV‐1 precisely and rapidly.
Differential UDP‐galactose‐4′‐epimerase (GALE) enzymatic activity and mRNA expression in the rat mammary gland during lactation
Authors: Prestoz Laetitia L.C , Daude Nathalie , Cournu Isabelle , Shin Yoon S , Petry Klaus G
Published: July 2002

We have investigated the UDP‐galactose‐4′‐epimerase (GALE) enzymatic activity and mRNA expression in the rat mammary gland during lactation. We report a dramatic increase in the GALE enzymatic activity correlated with an increase in the mRNA transcript expression. These results indicate a transcriptional regulation of the enzyme during lactation in the rat mammary gland. Our data are of double interest for further investigation: first, the mammary gland provides a suitable model for the characterisation of the transcriptional regulation elements of GALE which are still unknown in mammals; second, GALE expression could help to compensate UDP‐galactose deficiency in classic galactosaemia.
Cleavage experiments with deoxythymidine 3′,5′‐bis‐(p‐nitrophenyl phosphate) suggest that the homing endonuclease I‐PpoI follows the same mechanism of phosphodiester bond hydrolysis as the non‐specific Serratia nuclease1
Authors: Friedhoff Peter , Franke Ingo , Krause Kurt L , Pingoud Alfred
Published: July 2002

We show here that two nucleases, Serratia nuclease and I‐PpoI, with contrasting specificities, i.e. non‐specific vs. highly sequence specific, share a structurally similar active site region with conservation of the catalytically relevant histidine and asparagine residues. On the basis of a comparison of the available structures and biochemical data for wild type and mutant variants of Serratia nuclease and I‐PpoI we propose that both enzymes have a common catalytic mechanism, a proposition that is supported by our finding that both enzymes accept deoxythymidine 3′,5′‐bis‐(p‐nitrophenyl phosphate) as a substrate and cleave it in an identical manner. According to this mechanism a histidine residue functions as a general base and Mg2+ bound to an asparagine residue as a Lewis acid in phosphodiester bond cleavage.
Functional dissection of the R domain of cystic fibrosis transmembrane conductance regulator1
Authors: Tasch Jason E. , Zerhusen Bryan , Zhao Jiying , Ma Jianjie , Davis Pamela B.
Published: July 2002

Exogenously expressed unphosphorylated sub‐domains of the R domain block CFTR Cl− channels in the planar lipid bilayer, though the block differs from block with full length R domain. Full length R domain peptide (aa 588–855) blocks CFTR Cl− channels quickly, completely and permanently [1]. Two sub‐domains, RD1RD2 (aa 588–805) and RD2TM (aa 672–855), also inhibit CFTR Cl− channels, but the block takes longer to effect and is not complete. Shorter sequences, RD1 (aa 588–746) and RD2 (aa 672–805), fail to effect any block. These data suggest that either the amino‐terminal or carboxy‐terminal portions of the R domain protein or its stabilized secondary structure are critical to functional regulation.
Copper‐induced LDL peroxidation: interrelated dependencies of the kinetics on the concentrations of copper, hydroperoxides and tocopherol
Authors: Pinchuk Ilya , Lichtenberg Dov
Published: July 2002

Excessive uptake of oxidized low density lipoprotein plays a role in the onset of atherosclerosis. Lipid‐associated antioxidants, the most abundant of which is tocopherol (vitamin E), are therefore believed to have anti‐atherogenic properties. By contrast, hydroperoxides enhance the peroxidation of low density lipoprotein. We demonstrate that none of these compounds markedly affect the maximal rate of oxidation of low density lipoprotein, whereas the lag preceding rapid oxidation is prolonged by tocopherol but shortened by hydroperoxides. The corresponding ‘prolongation’ and ‘shortening’ can be compensated by each other in low density lipoprotein preparations enriched with both these compounds. The dependence of the balance between the effects of tocopherol and hydroperoxides on the copper concentration indicates that the antioxidative effect of vitamin E increases with the oxidative stress.
Determination of carbohydrate‐deficient transferrin separated by lectin affinity chromatography for detecting chronic alcohol abuse
Authors: Yoshikawa Kiyoshi , Umetsu Kazuo , Shinzawa Haruhide , Yuasa Isao , Maruyama Katsuya , Ohkura Takashi , Yamashita Katsuko , Suzuki Tsuneo
Published: July 2002

Carbohydrate‐deficient transferrin (CDT) has been established as a valuable biological marker for detecting chronic alcohol abuse. To improve the diagnostic efficiency, we studied new CDT determination procedures involving the use of lectin affinity chromatography with Allomyrina dichotoma agglutinin (allo A) and Trichosanthes japonica agglutinin I (TJA‐I) to isolate the CDT isoforms CDT‐allo A and CDT‐TJA, respectively. These procedures, based on detection of the CDT‐allo A and CDT‐TJA isoforms in sera, showed high sensitivity (100% and 98%, respectively) and high specificity (93% and 85%, respectively). These results demonstrate that the new procedures involving the use of lectin affinity chromatography are more useful for isolating markers in the CDT test than the conventional charge‐based separation method.
The X‐ray crystal structure of β‐ketoacyl [acyl carrier protein] synthase I
Authors: Olsen Johan Gotthardt , Kadziola Anders , von Wettstein-Knowles Penny , Siggaard-Andersen Mads , Lindquist Ylva , Larsen Sine
Published: July 2002

The crystal structure of the fatty acid elongating enzyme β‐ketoacyl [acyl carrier protein] synthase I (KAS I) from Escherichia coli has been determined to 2.3 Å resolution by molecular replacement using the recently solved crystal structure of KAS II as a search model. The crystal contains two independent dimers in the asymmetric unit. KAS I assumes the thiolase αβαβα fold. Electrostatic potential distribution reveals an acyl carrier protein docking site and a presumed substrate binding pocket was detected extending the active site. Both subunits contribute to each substrate binding site in the dimer.
Catalytic properties and conformation of hydrophobized α‐chymotrypsin incorporated into a bilayer lipid membrane
Authors: Kozlova N.O , Bruskovskaya I.B , Melik-Nubarov N.S , Yaroslavov A.A , Kabanov V.A
Published: July 2002

A set of artificially hydrophobized α‐chymotrypsin derivatives, carrying 2–11 stearoyl residues per enzyme molecule, were synthesized and their catalytic parameters and conformation in water solution and in the liposome‐bound state were investigated. Hydrophobization of α‐chymotrypsin and its further incorporation into phosphatidylcholine (PC) liposomes have no effect on the rate constant of the N‐acetyl‐L‐tyrosine ethyl ester (ATEE) ester bond hydrolysis (k
cat). At the same time, an increase in the number of stearoyl residues attached to the enzyme results in a drastic decrease of ATEE binding to the active center (K
M increase). Incorporation of the hydrophobized enzyme into the PC liposome membrane results in K
M recovery to nearly that of native α‐chymotrypsin. The above changes are accompanied by partial unfolding of the enzyme molecules observed by fluorescence measurements. The obtained results are of interest to mimic the contribution of surface hydrophobic sites in the functioning of membrane proteins.
Requirement of Pyk2 for the activation of the MAP kinase cascade induced by Ca2+ (but not by PKC or G protein) in PC12 cells
Authors: Barsacchi Rico , Heider Harald , Girault Jean-Antoine , Meldolesi Jacopo
Published: July 2002

The role of the Ca2+‐activated tyrosine kinase, Pyk2, in the pleiotropic coupling of nerve cell stimulation to the MAP kinase cascade still remains undefined. Using a panel of PC12 clones, one of which was defective in Pyk2, we demonstrate (1) that the MAP kinase response induced by a [Ca2+]i rise (following application of the Ca2+ ionophore, ionomycin) is inappreciable in the defective clone and is re‐established after Pyk2 transfection; and (2) that the responses to both protein kinase C and P2y2 receptor activation occur normally even in the defective cells. We conclude that Pyk2 is the key mediator in the pathway activated by Ca2+ but has minor roles with the other types of stimulation.
Serial analysis of gene expression in HIV‐1‐infected T cell lines
Authors: Ryo Akihide , Suzuki Youichi , Ichiyama Kouji , Wakatsuki Toru , Kondoh Nobuo , Hada Akiyuki , Yamamoto Mikio , Yamamoto Naoki
Published: July 2002

The gene expression profile of the HIV‐1 infection state was analyzed in the human T cell line MOLT‐4. Using the serial analysis of gene expression (SAGE) method, a total of 142 603 SAGE tags were sequenced and identified, representing 43 581 unique mRNA species. Comparison of expression patterns revealed that 53 cellular genes were differentially expressed upon HIV‐1 infection. Northern blot and RT‐PCR analyses confirmed the altered expression of the genes in both MOLT‐4 and MT‐4 cells. Up‐regulated genes were mainly composed of transcription factors and genes related to T cell activation, whereas down‐regulated genes were comprised of mitochondrial proteins, actin‐related factors and translational factors. These findings indicate that persistent T cell activation, which may accelerate HIV‐1 replication, and the disruption of cellular housekeeping genes including those involved in anti‐apoptotic systems, may play an important role in HIV‐1‐induced pathogenesis.
Infertility in American college alumnae
Authors: Wyshak G
Published: July 2002

Objective: The objective of this paper is to present data on prevalence of infertility, causes and treatments based on self‐reports of a sample of American college alumnae. Methods: A sample of 3940 American college alumnae, ages 37 to over 70 years, completed a self‐administered questionnaire relating to infertility, its causes, treatment and treatment outcomes. Results: Of the entire sample (n=3940), 3.1% (n=121) had primary infertility; 14.0% (n=548) had secondary infertility and were treated; 4.7% (n=184) tried for more than 1 year without success but had pregnancies without treatment; and 62.4% had no problems with infertility; and 16% (n=616) did not try to get pregnant. The major causes were ‘unexplained infertility’ reported by 43.5%; low sperm count or low motility, 21.4%; and anovulatory cycles, 20.3%. Treatment by clomid was reported by 39.5%. The overall success rate, resulting from treatment was 45%. The highest success rate occurred when anovulatory cycles were treated with clomid. Conclusion: Prevalence of primary and secondary infertility in this sample of American women is approximately 17%, similar to that observed for Sub‐Saharan Africa.
Riding the yield curve: Term premiums and excess returns
Authors: Pelaez Rolando F.
Published: July 2002

Riding the yield curve is an active portfolio strategy consisting of buying bonds with maturities longer than one's holding period and selling before maturity. The objective is to profit from a higher initial yield and a possible capital gain as the bond “rides” down an upward sloping yield curve. The evidence presented in this paper shows that compared with the buy‐and‐hold, 1‐year rides with 2‐year Treasury securities produce higher average returns, but do not yield excess risk‐adjusted returns. Incremental returns from riding represent term premiums, instead of pure profits. These findings are consistent with the liquidity premium theory of the term structure.
Effects of systematic education on heart failure patients' knowledge after 6 months. A randomised, controlled trial
Authors: Linné A. Björck , Liedholm H. , Israelsson B.
Published: July 2002

Background:

Many procedures for patient education are introduced in clinical practice without proper evaluation in randomised trials.

Aims:

To compare systematic nurse and pharmacist led education including an interactive Kodak Photo‐CD Portfolio technique with conventional information regarding heart failure patients' knowledge.

Methods:

One hundred and thirty heart failure patients discharged from hospital were randomised to receive either conventional information or additional structured education with a follow‐up of 6 months. Difference in knowledge was tested by questionnaire after 6 months.

Results:

At the end of the study there was a significant difference in the intervention group (n = 50) compared to the control group (n = 58) regarding knowledge as tested by a questionnaire. Of maximal 28 points the intervention group attained 17.2 points (mean) and the control group 14.3 points (mean), 95% confidence interval for difference 1.0–4.7 points (P = 0.0051).

Conclusions:

Two to 3 hours of systematic education improved heart failure patients' knowledge on essential issues. High age does not preclude the introduction of a new technique for patient education.
Prevention Through Design
Authors: Popov Georgi , Lyon Bruce , Popov Tsvetan
Published: December 2020

One of the most effective ways to reduce occupational risk is to avoid the introduction of hazards into the workplace. It is vitally important to manage workplace risks from the beginning stages of design throughout a system's life span to decommission and disposal. The process of anticipating, identifying, assessing, and controls hazards and their risks during design and throughout the life‐cycle of a system is known as prevention through design.
Quality of life in adults with achondroplasia in the United States
Authors: Yonko Elizabeth A. , Emanuel Jillian S. , Carter Erin M. , Raggio Cathleen L.
Published: December 2020

Studies examining quality of life (QoL) in adults with achondroplasia are limited. We report on QoL and psychiatric illness diagnoses in a modern cohort of adults with achondroplasia. SF‐36 Health Survey scores from adults with achondroplasia were compared to general population scores. Demographics, physical measurements, and psychiatric illness diagnoses were recorded from medical records. The achondroplasia population had lower scores than the general population in all categories. Most people with achondroplasia (56%) had a diagnosed psychiatric illness. Those with a diagnosed psychiatric illness had lower scores in physical functioning, role limitations due to physical and emotional health, and mental health. Pain, energy/fatigue, and general health scale scores were roughly equivalent (<2 points difference). Social functioning was >15 points higher in individuals with psychiatric illness diagnoses. Adults with achondroplasia report significantly lower physical and mental well‐being and had nearly 3× the rate of psychiatric illness diagnosis than the general population, highlighting the importance of total care for this population. Healthcare providers must understand the physical and mental comorbidities of achondroplasia, beyond short stature and orthopedic issues, so they can proactively improve QoL across the lifespan for patients and families.