bluuebunny/crossref_metadata_2025_split huggingface dataset:
The t(4;14) is associated with poor prognosis in myeloma patients undergoing autologous stem cell transplant
Authors: Chang Hong , Sloan Stephen , Li Dan , Zhuang Lihua , Yi Qi‐Long , Chen Christine I. , Reece Donna , Chun Kathy , Keith Stewart A. 
Published: July 2004

SummaryThe frequency and prognostic relevance of translocations t(11;14) and t(4;14), the most common translocations involving the immunoglobulin heavy chain (IgH) gene in multiple myeloma (MM), were investigated in 128 patients treated with intensive chemotherapy and autologous stem cell transplant. Myeloma cells were identified by cytoplasmic light chain immunofluorescence combined with fluorescence in situ hybridization (cIg‐FISH) for detection of translocations t(11;14) and t(4;14). Overall, t(11;14) was detected in 16 of 125 (12·8%) and t(4;14) in 15 of 120 (12·5%) patients. Progression‐free and overall survivals were similar for patients with or without t(11;14). However, patients with t(4;14) had significantly shorter progression‐free (median 9·9 months vs. 25·8 months; P = 0·0003) and overall survivals (median 18·3 months vs. 48·1 months; P < 0·0001) than patients without t(4;14). The t(4;14) was associated with IgA and t(11;14) with light chain MM. There was no association between the t(11;14) or t(4;14) and other biological parameters including age, gender, haemoglobin, β‐2 microglobulin, C‐reactive protein, calcium, creatinine, albumin, or the percentage of bone marrow plasma cells. Multivariate analysis identified t(4;14) as the only adverse prognostic factor for both progression‐free survival and overall survival. Our results indicate that the t(4;14) detected by cIg‐FISH is associated with a poor prognosis in MM patients receiving intensive chemotherapy and autotransplant.
A Model Relating Protein Osmotic Pressure to the Stiffness of the Cross‐Bridge Components and the Contractile Force of Skeletal Muscle
Authors: Grazi Enrico , Magri Ermes , Schwienbacher Christine , Trombetta Giorgio 
Published: July 2004

We have modeled the effect of protein osmotic pressure on the orientation of the monomer in F‐actin, in tropomyosin‐F‐actin, in the myosin subfragment‐1 decorated F‐actin and in the myosin subfragment‐1 decorated tropomyosin‐F‐actin.According to the model, at the physiological protein osmotic pressure (18 kPa), the elastic moduli by bending of the monomer in F‐actin and in tropomyosin‐F‐actin are calculated to be 4.74 MPa and 5.8 MPa, respectively. The elastic moduli by bending of the monomer in the myosin subfragment‐1 decorated F‐actin and in the myosin subfragment‐1 decorated tropomyosin‐F‐actin are calculated to be 22MPa and 22.3MPa, respectively. These latter values are in excellent agreement with the values of the elastic moduli by stretching found for the fibres of frog and rabbit muscle.We have also calculated that, at the physiological protein osmotic pressure, the myosin subfragment‐1 decorated F‐actin rigor complex can develop a force of 3.96 pN, a force correctly oriented to promote the sliding of the actin filament toward the center of the sarcomere. The magnitude of this force is comparable to that reported for intact skeletal muscle. In contrast, the myosin subfragment‐1 decorated tropomyosin‐F‐actin rigor complex develops a much smaller driving force, that favours relaxation. Apparently tropomyosin uncouples the osmotic and the mechanical event.It is proposed that the elastic energy for muscle contraction is provided by protein osmotic pressure.
Xylose‐DNA: Comparison of the Thermodynamic Stability of Oligo(2′‐deoxyxylonucleotide) and Oligo(2′‐deoxyribonucleotide) Duplexes
Authors: Schöppe Arnulf , Hinz Hans‐Jürgen , Rosemeyer Helmut , Seela Frank 
Published: July 2004

Measurements of differential scanning calorimetry, ultraviolet absorption and circular dichroism have been performed on two synthetic oligo(2′‐deoxyxylonucleotides): (A) d[(xA)3‐(xT)3‐(xA)3‐(xT)3‐T] and (B) d[(xA‐xT)6‐T], and on the oligo(2′‐deoxyribonucleotide) (C) d[(A)3‐(T)3‐(A)3‐(T)3]. Oligonucleotides having 2′‐deoxyxylose instead of 2′‐deoxyribose exhibit unusual thermodynamic, optical and structural features. At identical concentrations the transition temperatures of the oligo(2′‐deoxyxylooligomers) are higher than those of the oligo(2′‐deoxyribooligomers) indicating higher stability. The calorimetric transition enthalpy of (C) is 270 ± 15 kJ·mol−1, the corresponding van′t Hoff value is 280 ± 15 kJ·(mol of cooperative unit)−1. The ratio of ΔHvH/ΔHcal= 1.04 suggests all‐or‐none behaviour for the transition of the 2′‐deoxyribose oligonucleotide.The analogous parameters of (A) are: ΔHcal= 310 ± 30 kJ·mol−1, ΔHvH= 220 ± 30 kJ·(mol of cooperative unit)−1. The ratio of 0.71 indicates multistate melting for this compound. The sequence dependence of the thermodynamic quantities becomes apparent when the parameters of the alternating oligo(2′‐deoxyxylonucleotide) d[(xA‐xT)6‐T] are compared to those of d[(xA)3‐(xT)3‐(xA)3‐(xT)3‐T]. The values of (B) are ΔHcal= 330 ± 30 kJ·mol−1; ΔHvH= 180 ± 15 kJ·(mol of cooperative unit)−1ΔHvH/ΔHcal= 0.55. The transition enthalpy of the alternating oligo(2′‐deoxyxylonucleotide) (B) is the highest but the cooperativity of transition is the lowest of the oligonucleotides studied. The circular dichroic spectra of the two oligo(2′‐deoxyxylonucleotides) show unusual features in that d[(xA)3‐(xT)3‐(xA)3‐(xT)3‐T] exhibits a spectrum that is suggestive of a left‐handed double helix, while the spectrum of the alternating oligo(2′‐deoxyxylonucleotide) (B) resembles neither that of (C) nor that of (A).
Brominated Detergents as Tools to Study Protein‐Detergent Interactions
Authors: de Foresta Béatrice , Legros Nathalie , Plusquellec Daniel , Le Maire Marc , Champeil Philippe 
Published: July 2004

In order to study protein‐detergent short‐range interactions, we analyzed the quenching by brominated detergents of reticulum sarcoplasmic (SR) Ca2+‐ATPase intrinsic fluorescence. For this purpose, 7,8‐dibromododecyl β‐maltoside and 2‐O‐(10,11‐dibromoundecanoyl)sucrose, brominated analogs of two non‐ionic detergents, the frequently used dodecylmaltoside and the newly synthesized 2‐O‐lauroylsucrose respectively, were prepared.Rayleigh scattering measurements showed that the brominated detergents efficiently and rapidly solubilized SR vesicles like their non‐brominated analogs although at slightly higher concentrations. Similarly, each analog had a slightly higher critical micellar concentration than its parent detergent. The partition coefficient K (expressed as the ratio of the molar fraction of detergent in the SR lipid phase to that in the aqueous phase, at pH 7.5 and 20°C) was similar for brominated and non‐brominated dodecyl maltoside (3.5–4 × 105) and slightly lower for dibromoundecanoylsucrose (≈105) than for lauroylsucrose (≈ 2 × 105).At detergent concentrations too low to solubilize the membrane, the brominated detergents rapidly inserted (within seconds) into SR vesicles. In this concentration range, Ca2+‐ATPase fluorescence quenching steadily increased with detergent concentration. When the membrane was saturated with detergent, the residual fluorescence was about half of its initial value, indicating significant protein‐detergent contacts, possibly due to a slightly higher affinity of Ca2+‐ATPase for these detergents than for phospholipids. For higher detergent concentrations, solubilizing the membrane, the fluorescence continued to decrease with detergent concentration, with no evidence for a dramatic change in the average hydrophobic environment of the protein during the transition from bilayers to a soluble state. For still higher detergent concentrations, above that necessary for membrane solubilization, the fluorescence was further quenched to a residual relative value of about 20%, corresponding to further delipidation of the protein surface, in agreement with previous results [de Foresta, B., le Maire, M., Orlowski, S., Champeil, P., Lund, S., Møller, J. V., Michelangeli, F. & Lee, A. G. (1989)Biochemistry 28, 2558–25671. Fluorescence quenching for solubilized Ca2+‐ATPase was quickly reversed upon addition of excess non‐brominated detergent. The effects of the four detergents on the Ca2+‐ATPase hydrolysis of p‐nitrophenyl phosphate were similar and correlated with the protein‐detergent contacts evidenced above. In conclusion, both these brominated detergents appear to be promising tools to study protein‐detergent interactions at the hydrophobic surface of a membrane protein, either in a membrane or in solubilized complexes.
Follitropin Action on the Transferrin Gene in Sertoli Cells is Mediated by cAMP‐Responsive‐Element‐Binding‐Protein and Antagonized by Chicken Ovalbumin‐Upstream‐Promoter‐Transcription Factor
Authors: Suire Sabine , Maurel Marie‐Christine , Guillou Florian 
Published: July 2004

The transcription of the transferrin (Tf) gene is induced by follitropin via cAMP in rat Sertoli cells. We previously demonstrated that the cAMP‐responsive‐element‐binding protein (CREB) interacts on the proximal region II (PRII) of the human Tf promoter (Suire et al., 1995). The PRII region is identified as essential for cAMP inducibility of the Tf promoter and contains a CCAAT box. This unexpected result led us to study the relation that exists between CREB and the PRII site.In the liver, CCAAT/enhancer‐binding (C/EBP) proteins act at the PRII site. Although these factors are absent in Sertoli cells, their overexpression in Sertoli cells disturbs basal and induced transcription. C/EBP α and δ were able to stimulate the basal transcription driven by the–100 to +39 region, placed upstream of the chloramphenicol acetyltransferase (CAT) gene. However, only C/EBPα allowed the cAMP‐inducible expression.The Ka of CREB bZIP (254–327), a deleted form of CREB, for the CRE site (3.92 × 108M−1) and for the PRII site (1.38 × 108M−1) were determined using the surface plasmon resonance (SPR) method. The Ka values were similar, although the derived kinetics were different: higher ka and kd of CREB for the PRII site were found compared with the CRE site.Since we observed important dissociation kinetics, we hypothesized that the binding of CREB to the PRII site is stabilized by CREB‐binding protein (CBP) or by chicken‐ovalbumin‐upstream‐promoter transcription factor (COUP‐TF) binding to PRI site near to PRII. However, we observed that the overexpression of CBP in Sertoli cells did not potentiate the basal and cAMP‐stimulated activity of CREB of the–100 to +39Tf‐CAT construct. In basal and cAMP‐stimulated conditions, COUP‐TF appeared to repress the transcription driven by the–100 to +39 region in a specific manner.These results demonstrate a direct action of CREB on hTf promoter, which is antagonized by COUPTF and may explain the transcriptional regulation of Tf by follitropin, via cAMP.
The Lurlenes, a New Class of Plastoquinone‐Related Mating Pheromones from Chlamydomonas Allensworth (Chlorophyceae)
Authors: Jaenicke Lothar , Starr Richard C. 
Published: July 2004

Chlamydomonas allensworth is a recently described species, which differs phenotypically and in its reproductive behaviour from other members of this genus of flagellated green protists. Its female cells temporarily or constantly excrete a luring signal into the medium to attract the male cells for mating. The sperm is susceptible to the pheromone either all the time or only after a maturation process. Maturation in this species is accompanied with a colour shift from green to khaki (strain from Lemon Cove CA) or to olive (strain from Catarina TX), apparently due to degradation of chloroplast material. In the bioassay with polyacrylamide beads (plain or DEAE‐substituted) to which the lures are bound, acting as mock females, Catarina‐strain males are only attracted to Catarina strain lures, whereas Lemon‐Cove‐strain males are attracted to Lemon‐Cove‐strain lures and to a lesser extent, to Catarina‐strain lures. Being amphiphilic acid, Lemon‐Cove‐strain lure is more tightly bound to DEAE beads. Catarina‐strain lure is an uncharged amphiphile. The two signal compounds have been isolated and identified by chemical analysis and mass and NMR spectroscopies as 0(5)‐β‐D‐xylosylated degradation products of the chloroplast electron transporter hydroplastoquinone, its polyprenoid side chain being oxidatively cleaved at the fourth double bond. Lurlenic acid (lurlene L) is the resulting acid and lurlenol (lurlene C) the corresponding alcohol. The pheromonal activities of both compounds have a threshold at 1 pM, and are destroyed by deglycosylation and subsequent oxidation to the quinonoid aglycon.This class of amphiphilic lures, having the same basic glycosylated hydroquinone structure, is named lurlenes.
Structure and Biological Activity of Chemically Modified Nisin A Species
Authors: Rollema Harry S. , Metzger Jörg W. , Both Paula , Kuipers Oscar P. , Siezen Roland J. 
Published: July 2004

Nisin, a 34‐residue peptide bacteriocin, contains the less common amino acids lanthionine, β‐methyl‐lanthionine, dehydroalanine (Dha), and dehydrobutyrine (Dhb). Several chemically modified nisin A species were purified by reverse‐phase HPLC and characterized by two‐dimensional NMR and electrospray mass spectrometry. Five constituents, [2‐hydroxy‐Ala5]nisin, [Ile4‐amide,pyruvyl‐Leu6]des‐Dha5‐nisin, [Met(O)21]nisin, [Ser33]nisin, and nisin‐(1–32)‐peptide amide, were found in a commercial nisin sample. A further species, [2‐hydroxy‐Ala5]nisin‐(1–32)‐peptide amide, was obtained by freeze drying an acidic nisin solution. These compounds are formed by chemical modification of nisin: the addition of a water molecule to the dehydroalanine residues, which can lead to the cleavage of the polypeptide chain, or the oxidation of methionine residues.The 2‐hydroxyalanine‐containing products have a limited stability; they are spontaneously converted into the corresponding des‐dehydroalanine derivatives. The growth‐inhibiting activity of the modified nisins towards different bacteria was determined. The 2‐hydroxyalanine‐containing species and the des‐dehydroalanine derivative show a strong reduction in biological activity as compared to native nisin. [Met(O)21]nisin and [Ser33]nisin show moderate or no reduction in biological activity.
Characterization of a 3α‐Hydroxysteroid Dehydrogenase/Carbonyl Reductase from the Gram‐Negative Bacterium Comamonas testosteroni
Authors: Oppermann Udo C. T. , Maser Edmund 
Published: July 2004

A new form of the NAD(P)‐dependent 3α‐hydroxysteroid dehydrogenases (3α‐HSDs), present in the gram‐negative bacterium Comamonas testosteroni ATCC 11996, was isolated from a testosterone‐induced bacterial extract and characterized. The enzyme (HSD 28) has a monomeric molecular mass of 28 kDa. It belongs to the protein superfamily of short‐chain dehydrogenases/reductases (SDR) as established by N‐terminal sequence analysis. Along with the 3α‐hydroxysteroid dehydrogenase and 3‐oxo‐reductase activities towards a variety of cis or trans fused A/B ring steroids, it also reduces several xenobiotic carbonyl compounds, including a metyrapone‐based class of insecticides, to the respective alcohol metabolites. No dihydrodiol dehydrogenase activity towards trans‐ or cis‐benzene‐dihydrodiols could be detected, thus distinguishing it from the indomethacine‐sensitive, mammalian liver type 3α‐HSDs. Subcellular fractionation revealed that the enzyme is localized in the cytoplasm of the bacterial cell. Proteins similar to the 3α‐HSD were detected and characterized from Comamonas testosteroni strain ATCC 17454 and from a commercially available steroid‐induced extract of a patent Pseudomonas strain. The N‐terminal amino acid sequence of the 3α‐HSD from the latter strain (HSD 29) is highly similar (94% identity over 15 residues) to a previously determined primary structure of a Pseudomonas species 3α‐HSD. However, no similarities could be detected between HSD 28 and a recently determined 3α‐HSD sequence from the ATCC 11996 Comamonas strain.The specific crossreaction of antibodies directed against mammalian liver type I 11β‐hydroxysteroid dehydrogenase (11β‐HSD I) with the isolated 3α‐HSDs suggests the existence of a functionally and structurally related subgroup within the SDR superfamily. The broad substrate specificities of the characterized 3α‐HSD enzymes lead to the conclusion that they might participate in the intestinal bioactivation or inactivation of hormones, bile acids and xenobiotics since Comamonas testosteroni and related species are found in the intestinal tract of vertebrates including man.
Evidence for Propeptide‐Assisted Folding of the Calcium‐Dependent Protease of the Cyanobacterium Anabaena
Authors: Baier Kerstin , Nicklisch Sabine , Lockau Wolfgang 
Published: July 2004

The Ca2+‐dependent protease of the cyanobacterium Anabaena variabilis is a cytoplasmic enzyme with a substrate specificity like trypsin. Its previously published DNA sequence [Maldener, I., Lockau, W., Cai, Y. & Wolk, C. P. (1991)Mol. Gen. Genet. 225, 113–120] contained a sequencing error. Here we report the corrected sequence which shows, that the Ca2+‐protease belongs to the family of subtilases (subtilisin‐like serine proteases). Consistent with its cytoplasmic localization, a pre‐sequence is not found.The enzyme is produced as a precursor with a large amino‐terminal propeptide. Expression of the pro‐region and mature region (protease domain) in Escherichia coli cells in trans demonstrates that formation of the active enzyme requires the propeptide. The results demonstrate that propeptide‐assisted protein folding also occurs with cytoplasmic enzymes, in support of the hypothesis that this mechanism is a widespread phenomenon.
The Primary Structure and Characterization of Carbohydrate Chains of the Extracellular Glycoprotein Proteinase Inhibitor from Latex of Carica Papaya
Authors: Odani Shoji , Yokokawa Yayoi , Takeda Hiroshi , Abe Sachiko , Odani Sumiko 
Published: July 2004

A secretory proteinase inhibitor was isolated from the latex of green fruits of papaya (Carica papaya). The protein exhibited stoichiometric inhibition of bovine trypsin and α‐chymotrypsin by the same site or overlapping binding sites. The complete covalent structure consisting of 184 amino acids and two disulfide bonds was determined by protein analysis. During the structural analysis, a procedure was established to separate very hydrophilic peptides by reverse‐phase HPLC. The result revealed that the latex protein belongs to an extensively diverse plant protein family that includes inhibitors of serine, cysteine and aspartic proteases, a taste‐modifying protein, wound responsive proteins, storage proteins, amylase inhibitors and even an oxidoreductase. In this superfamily, the latex proteinase inhibitor is most similar to the curious protein, miraculin, which makes sour food taste sweet.Two carbohydrate chains, each probably composed of (mannose)5, (xylose)1, (fucose)0‐2, and (N ‐acetylglucosamine)2 residues, were attached to asparagine 84 and 90. Mass‐spectrometric and compositional analysis suggested that they may represent a new class of plant xylose‐containing carbohydrate chains with five mannose residues.
An Example of Non‐Conservation of Oligomeric Structure in Prokaryotic Aminoacyl‐tRNA Synthetases
Authors: Mazauric Marie‐Hélène , Reinbolt Joseph , Lorber Bernard , Ebel Christine , Keith Gérard , Giegé Richard , Kern Daniel 
Published: July 2004

Glycyl‐tRNA synthetase (Gly‐tRNA synthetase) from Thermus thermophilus was purified to homogeneity and with high yield using a five‐step purification procedure in amounts sufficient to solve its crystallographic structure [Logan, D. T., Mazauric, M.‐H., Kern, D. & Moras, D. (1995)EMBO J. 14, 4156–4167]. Molecular‐mass determinations of the native and denatured protein indicate an oligomeric structure of the α2 type consistent with that found for eukaryotic Gly‐tRNA synthetases (yeast and Bombyx mori), but different from that of Gly‐tRNA synthetases from mesophilic prokaryotes (Escherichia coli and Bacillus brevis) which are α2β2 tetramers. N‐terminal sequencing of the polypeptide chain reveals significant identity, reaching 50% with those of the eukaryotic enzymes (B. mori, Homo sapiens, yeast and Caenorhabditis elegans) but no significant identity was found with both α and β chains of the prokaryotic enzymes (E. coli, Haemophilus influenzue and Coxiella burnetii) albeit the enzyme is deprived of the N‐terminal extension characterizing eukaryotic synthetases. Thus, the thermophilic Gly‐tRNA synthetase combines strong structural homologies of eukaryotic Gly‐tRNA synthetases with a feature of prokaryotic synthetases.Heat‐stability measurements show that this synthetase keeps its ATP‐PPi exchange and aminoacylation activities up to 70°C. Glycyladenylate strongly protects the enzyme against thermal inactivation at higher temperatures. Unexpectedly, tRNAGly does not induce protection.Cross‐aminoacylations reveal that the thermophilic Gly‐tRNA synthetase charges heterologous E. coli tRNAGly(GCC) and tRNAGly(CCC) and yeast tRNAGly(GCC) as efficiently as T. thermophilus tRNAGly. All these aminoacylation reactions are characterized by similar activation energies as deduced from Arrhenius plots. Therefore, contrary to the E. coli and H. sapiens Gly‐tRNA synthetases, the prokaryotic thermophilic enzyme does not possess a strict species specificity.The results are discussed in the context of the three‐dimensional structure of the synthetase and in the view of the particular evolution of the glycinylation systems.
Origin of the Two Carbonyl Oxygens of Bacteriochlorophyll a
Authors: Porra Robert J. , Schäfer Wolfram , Gad'on Nasr , Katheder Ingrid , Drews Gerhart , Scheer Hugo 
Published: July 2004

A respiring culture of Rhodobacter sphaeroides, grown in the dark under defined aerobic conditions, produced cells capable of immediately commencing adaptation to photosynthetic growth on exposure to light and further reduction of oxygen tension. Adaptation was complete after 12 h and the bacteriochlorophyll a content increased 10–20‐fold. This adaptation was performed in the presence of either H218O or 18O2. The extracted bacteriochlorophyll a was examined by mass spectrometry to determine the origin of both the 3‐acetyl and 131‐oxo oxygen atoms: both were derived from water.The derivation of the 131‐oxo group from water in R. sphaeroides indicates that the formation of isocyclic ring E from the 13‐propionic acid methylester side chain of Mg2+‐protoporphyrin IX mono‐methylester is an anaerobic process involving a hydratase. This is very different to the situation in higher plants and green algae where the formation of isocyclic ring E is an aerobic process in which the 131‐oxo group is derived from molecular oxygen via an oxygenase.In contrast to adapting R. sphaeroides cells, the 131‐oxo group of bacteriochlorophyll a in growing cells of the obligate aerobic chemotrophic bacterium Roseobacter denitrificans, was labelled by 18O2 and is, therefore, derived from molecular oxygen like in higher plants and green algae; however, the 3‐acetyl group was not labelled by 18O2. Thus, while the 131‐oxo group has different origins in R. sphaeroides and R. denitrificans, the 3‐acetyl group arises in both bacteria by enzymic hydration of the vinyl group of a chlorophyll a derivative.