Charles Tellier

• Professor
• Nantes Université

Microalgae are a promising alternative resource to fossil-based products. Botryococcus braunii is a colonial green microalga having the ability to convert CO2 by photosynthesis into long chain hydrocarbons. These are excreted and trapped in an extracellular matrix (ECM). A panel of glycosidases ranging from arabinanase, galactananase to endoglucana...

Objectives To search for new alkaliphilic cellulases and to improve their efficiency on crystalline cellulose through molecular engineering Results Two novel cellulases, BpGH9 and BpGH48, from a Bacillus pumilus strain were identified, cloned and biochemically characterized. BpGH9 is a modular endocellulase belonging to the glycoside hydrolase 9 f...

Bacterial sialidases (SA) are validated drug targets expressed by common human pathogens such as Streptococcus pneumoniae, Vibrio cholerae, or Clostridium perfringens. Noncovalent inhibitors of bacterial SA capable of reaching the submicromolar level are rarely reported. In this work, multi‐ and polyvalent compounds are developed, based on the tran...

div>Conjugation of the transitionstate-cation analogue DANA to polymeric scaffolds led to highly potent inhibitors of bacterial sialidases. Each clustered DANA on the polymers saw its inhibitory potency for S. pneumoniae or B. thetaiotaomicron sialidases improved by more than four orders of magnitude. This extends the multivalent concept to this im...

Background The demand for a carbohydrate driven economy coupled with the abundant cellulosic biomass has driven the search for cellulases that can be applied for the utilization of the cellulosic biomass. Context of the study Of special focus for our study is cotton, which is the preferred textile fiber given its favorable high quality. In addition...

Glycoside hydrolases and phosphorylases are two major classes of enzymes responsible for the cleavage of glycosidic bonds. Here we show that two GH84 O-GlcNAcase enzymes can be converted to efficient phosphorylases by a single point mutation. Noteworthy, the mutated enzymes are over ten-fold more active than naturally occurring glucosaminide phosph...

Using the information available in the sequences of well-characterized transglycosidases found in plants, mutations were introduced in the glycoside hydrolase of the bacterium Thermus thermophilus, with the aim of turning it into an efficient transglycosidase. All mutants happen to have fair catalytic efficiencies, being at worst 25 times less effi...

Agars are sulfated galactans from red macroalgae and are composed of a D-galactose (G unit) and L-galactose (L unit) alternativelylinkedbyα-1, 3 and β-1, 4 glycosidicbonds. The sepolysaccharides display high complexity, with numerous modifications of their backbone (e.g. presence of a 3, 6-anhydro-bridge (LA unit) and sulfations and methylation). C...

Sialidases (SAs) hydrolyze sialyl residues from glycoconjugates of the eukaryotic cell surface and are virulence factors expressed by pathogenic bacteria, viruses, and parasites. The catalytic domains of SAs are often flanked with carbohydrate‐binding module(s) previously shown to bind sialosides and to enhance enzymatic catalytic efficiency. Herei...

Glycan microarrays are useful tools for lectin glycan profiling. The use of glycan microarray based on evanescent-field fluorescence detection is herein further extended to the screening of lectin inhibitors in competitive experiments. Efficacy of this approach has been tested with 2/3' mono- or di-aromatic type II lactosamine derivatives and galec...

Glycosidase effectors have rarely been reported despite their great potential interest in pharmaceutical sciences and industry. Magnetic nanoparticles were coated with thiomannosides (SMan@Fe3O4) or the broad spectrum glycosidase inhibitor deoxynojirimycin (DNJ@Fe3O4). The coated ligands were shown to exert a fully reverse effect on a model galacto...

Streptoccocus pneumoniae is a bacteria responsible for serious diseases such as pneumonia or meningitis and leads to the death of approximately one million of children each year. Efficient anti-pneumococcal glycoconjugate vaccines made of bacterial capsular polysaccha-rides have been launched. However, these vaccines confer protection to seven or t...

Koenigs-Knorr glycosylation of acceptors with more than one free hydroxyl group by 2,3,5,6-tetrabenzoyl galactofuranosyl bromide was performed using diphenylborinic acid 2-aminoethyl ester (DPBA) as inducer of regioselectivity. High regioselectivity for the glycosylation on the equatorial hydroxyl group of the acceptor was obtained thanks to the tr...

In retaining glycoside hydrolases (GHs), transglycosylase activity is often low due to the natural hydrolytic activity that is favored in water. Improving the relative transglycosylase activity of these enzymes is of particular interest to obtain enzymes suitable for the synthesis of oligosaccharides. We explored the effect of engineering the water...

The back cover picture shows the collective keratinocyte migration that typically occurs during wound-healing. This highly efficient and complex process is driven by leader cells at the front of the cells, while the follower cells remain in close contact to move in concert. Galectin-3 is one of the key actors that control this fascinating example o...

Galectins have been recognized as potential novel therapeutic targets in connection with the numerous fundamental biological processes which they are involved in. Galectins are key players of homeostasis and as such, their expression and function are finely tuned in vivo. As a consequence, their modes of action are complex and remain largely unexpl...

Different routes for preparing zirconium phosphonate-modified surfaces for immobilizing biomolecular probes are compared. Two chemical-modification approaches were explored to form self-assembled monolayers on commercially available primary amine-functionalized slides, and the resulting surfaces were compared to well-characterized zirconium phospho...

Objectives: To design a new system for the in vivo phosphorylation of proteins in Escherichia coli using the co-expression of the α-subunit of casein kinase II (CKIIα) and a target protein, (Nanofitin) fused with a phosphorylatable tag. Results: The level of the co-expressed CKIIα was controlled by the arabinose promoter and optimal phosphorylat...

Human milk oligosaccharides (HMOs) are recognized as benefiting breast-fed infants in multiple ways. As a result, there is growing interest in the synthesis of HMOs mimicking their natural diversity. Most HMOs are fucosylated oligosaccharides. α-l-Fucosidases catalyze the hydrolysis of α-l-fucose from the non-reducing end of a glucan. They fall int...

Although leishmaniasis has been studied for over a century, the fight against cutaneous, mucocutaneous and visceral forms of the disease remains a hot topic. This review refers to the parasitic cell wall and more particularly to the constitutive glycoconjugates. The structures of the main glycolipids and glycoproteins, which are species-dependent,...

Multivalent iminosugars have recently emerged as powerful tools to inhibit the activities of specific glycosidases. In this work, biocompatible dextrans were coated with iminosugars to form linear and ramified polymers with unprecedently high valencies (from 20 to 900) to probe the evolution of the multivalent inhibition as a function of ligand val...

A large number of retaining glycosidases catalyze both hydrolysis and transglycosylation reactions. In order to use them as catalysts for oligosaccharide synthesis, the balance between these two competing reactions has to be shifted toward transglycosylation. We previously designed a semi-rational approach to convert the Thermus thermophilus β-glyc...

Glycoside hydrolases are particularly abundant in all areas of metabolism as they are involved in the degradation of natural polysaccharides and glycoconjugates. These enzymes are classified into 133 families (CAZy server, http://www.cazy.org) in which members of each family have a similar structure and catalytic mechanism. In order to understand b...

The attachment of affinity proteins onto zirconium phosphonate coated glass slides was investigated by fusing a short phosphorylated peptide sequence at one extremity to enable selective bonding to the active surface via the formation of zirconium-phosphate coordinate-covalent bonds. In a model study, the binding of short peptides containing zero t...

Random mutagenesis was performed on the α-l-arabinofuranosidase of Thermobacillus xylanilyticus in order to enhance its ability to perform transarabinofuranosylation using natural xylo-oligosaccharides as acceptors. To achieve this goal, a two-step, high-throughput digital imaging protocol involving a colorimetric substrate was used to screen a lib...

A large number of retaining glycosidases catalyze both hydrolysis and transglycosylation reactions, but little is known about what determines the balance between these two activities (transglycosylation/hydrolysis ratio). We previously obtained by directed evolution the mutants F401S and N282T of Thermus thermophilus β-glycosidase (Ttβ-gly, glycosi...

Taking advantage of the wealth of structural data available for family 1 glycoside hydrolases, a study of the conservation of internal water molecules found in this ubiquitous family of enzymes was undertaken. Interestingly, seven water molecules are observed in more than 90% of known structures. In order to gain insights about their possible funct...

Alkoxyamino derivatives of oligosaccharides have been synthesized by enzymatic synthesis using a glycosynthase and a transglycosidase. The chemoselective assembly of unprotected oligosaccharides bearing glucose at the reducing end with N-alkyl-O-benzylhydroxylamine provides sugar derivatives that are good acceptors for enzymatic synthesis using eit...

A phosphorylatable tag was designed and fused at the C-terminal end of proteins, which allowed efficient and oriented immobilization of capture proteins on glass substrates coated with a zirconium phosphonate monolayer. The concept is demonstrated using Nanofitin directed against lysozyme. This peptide tag (DSDSSSEDE) contains four serines in an ac...

The stereocontrolled synthesis of β-galactosyl-5-aza-sphinganines was accomplished with high efficiency by a novel and convergent strategy. The truncated β-galactosphinganine 5 was easily acylated with different long chains. Moreover, the simple conversion of thiazole to formyl enabled 5-aza-alkylchains to be introduced via an amino-reduction react...

Directed evolution was used to generate IL-15 mutants with increased solubility and cytoplasmic over-expression in Escherichia coli. A protein solubility selection method was used in which the IL-15 gene was expressed as an N-terminal fusion to chloramphenicol acetyltransferase (CAT) as reporter protein. Clones that grew in the presence of high con...

The activity and stability of a β-glycosidase (Thermus thermophilus) and two α-galactosidases (Thermotoga maritima and Bacillus stearothermophilus) were studied in different hydrophilic ionic liquid (IL)/water ratios. For the ILs used, the glycosidases showed the best stability and activity in 1,3-dimethylimidazolium methyl sulfate [MMIM][MeSO4] an...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Mutant N282T of a thermostable beta-glycosidase from GH1 family (TtbetaGly) presenting a high transglycosidase activity was previously obtained by directed evolution. However, it displays a self-condensation activity with the donor 2-nitrophenyl-beta-d-galactopyranoside (oNPGal) which competes with the condensation reaction and entails undesirable...

Two bisphosphonate adaptors were designed to immobilize histidine-tagged proteins onto glass substrates coated with a zirconium phosphonate monolayer, allowing efficient and oriented immobilization of capture proteins, affitins directed to lysozyme, on a microarray format. These bifunctional adaptors contain two phosphonic acid anchors at one extre...

Mutant glycosynthases or transglycosidases obtained from a Thermus thermophilus beta-D-glycosidase (Ttb-Gly) efficiently catalyzed the synthesis of beta-(1 -> 3)-disaccharides. Unfortunately, this regioselectivity was changed to the beta-(1 -> 4) one when N-acetylglucosamine derivatives were used as acceptors, thus precluding the possibility of syn...

Mutant glycosynthases or transglycosidases obtained from a Thermus thermophilus b-D-glycosidase (Ttb-Gly) efficiently catalyzed the synthesis of b-(1?3)-disaccharides. Unfortunately, this regioselectivity was changed to the b-(1?4) one when N-acetylglucosamine derivatives were used as acceptors, thus precluding the possibility of synthesizing D-Gal...

Engineering of glycosidases with efficient transglycosidases activity is an alternative to glycosyltransferases or glycosynthases for the synthesis of oligosaccharides and glycoconjugates. However, the engineering of transglycosidases by directed evolution methodologies is hampered by the lack of efficient screening systems for sugar-transfer activ...

Numerous synthetic cationic vectors have been synthesized and are successfully used for in vitro gene transfer but an excess of positive charges can lead to cytotoxicity and does not enable specific transfection. We decided to develop alternative molecular systems consisting of neutral, colloidally stable bioassemblies equipped with ligands for spe...

Glycosynthase mutants obtained from Thermotogamaritima were able to catalyze the regioselective synthesis of aryl beta-D-Galp-(1-->3)-beta-D-Glcp and aryl beta-D-Glcp-(1-->3)-beta-D-Glcp in high yields (up to 90 %) using aryl beta-D-glucosides as acceptors. The need for an aglyconic aryl group was rationalized by molecular modeling calculations, wh...

A spacer is often employed between the surface linking group and the probe sequence to improve the performance of DNA microarrays. Previous work demonstrated that a consecutive stretch of guanines as a spacer increased target capture during hybridization relative to probes with either no spacer or a similar stretch of one of the other nucleotides....

Terminal phosphate groups on double-stranded DNA probes bind strongly to glass substrates coated with a zirconium phosphonate monolayer, and probes immobilized in this way as microarrays can be used to detect protein targets. The sensitivity of the microarray was shown to be enhanced by the use of a polyguanine segment ((G)n , n > or = 5) as a spac...

The aim of this study was to develop an Escherichia coli-based metabolic selection system for the uncovering of new oligogalacturonate-active enzymes. Based on the expression of the specific permease TogMNAB, this system enabled the entry of oligogalacturonates into the cytoplasm of E. coli thus providing a modified strain usable for this purpose....

The alpha-L-fucosidase from Thermotoga maritima (Tm alpha fuc) was converted into alpha-L-transfucosidase variants by directed evolution. The wild-type enzyme catalyzes oligosaccharide synthesis by transfer of a fucosyl residue from a pNP-fucoside donor to pNP-fucoside (self-condensation) with alpha-(1-->3) regioselectivity or pNP-galactoside (tran...

A new process for preparing oligonucleotide arrays is described that uses surface grafting chemistry which is fundamentally different from the electrostatic adsorption and organic covalent binding methods normally employed. Solid supports are modified with a mixed organic/inorganic zirconium phosphonate monolayer film providing a stable, well-defin...

A new process for preparing oligonucleotide arrays is described that uses surface grafting chemistry which is fundamentally different from the electrostatic adsorption and organic covalent binding methods normally employed. Solid supports are modified with a mixed organic/inorganic zirconium phosphonate monolayer film providing a stable, well-defin...

Directed evolution was applied to the beta-glycosidase of Thermus thermophilus in order to increase its ability to synthesize oligosaccharide by transglycosylation. Wild-type enzyme was able to transfer the glycosyl residue with a yield of 50% by self-condensation and of about 8% by transglycosylation on disaccharides without nitrophenyl at their r...

Prodrug activation: Serum albumins (BSA or HSA) are shown to catalyze a reaction cascade that involves the ring-opening of an isoxazole ring followed by a β-elimination reaction, as per the scheme. The 4-(aryloxymethyl) isoxazole derivative of estrone is selectively removed in vitro by albumins, thus demonstrating the potential of this new protecti...

Inverting mutant glycosynthases were designed according to the Withers strategy, starting from wild-type Thermus thermophilus retaining Tt-β-Gly glycosidase. Directed mutagenesis of catalytic nucleophile glutamate 338 by alanine, serine, and glycine afforded the E338A, E338S, and E338G mutant enzymes, respectively. As was to be expected, the mutant...

The cover picture shows the molecular modeling of the active site of a “glycosynthase” mutant obtained by directed mutagenesis (E338S) of the native thermostable Tt-β-Glyglycosidase from Thermus thermophilus. The relative orientations of the donor (α-D-glucopyranosyl fluoride) and of the acceptor (phenyl β-D-glucopyranoside), which corresponded to...

Communication orale intitulée : Nouveau concept pour la préparation de Puces à ADN

The antibody Fv fragment is the smallest functional unit of an antibody but for practical use, the VH/VL interface requires stabilization, which is usually accomplished by a peptide linker that joins the two variable domains to form a single chain Fv fragment (scFv). An alternative format to scFv is proposed that (i) allows stabilization of the Fv...

A new approach to oligonucleotide arrays is demonstrated that utilizes zirconium phosphonate-derivatized glass slides. The active slides are prepared by binding Zr(4+) to surfaces terminated with organophosphonate groups previously deposited using either Langmuir-Blodgett or self-assembled monolayer methods. Oligonucleotide probes modified with a t...

The synthesis of carbasugars and various aminocyclitols, related to voglibose and acarbose used in the treatment of non-insulino-dependant diabetes, is described from C2-symmetrical bis-epoxides derived from d-mannitol. The methodology involves two key steps: a domino alkylation–cyclization with 2-lithio-1,3-dithiane derivatives, and reduction or r...

Antibodies represent an interesting protein framework on which catalytic functions can be grafted. In previous studies, we have reported the characterization of the catalytic antibody 4B2 obtained on the basis of the "bait and switch" strategy which catalyzes two different chemical reactions: the allylic isomerization of beta,gamma-unsaturated keto...

A proteinaceous inhibitor of alpha-amylase, Tendamistat, was evaluated as an immunogen to induce antibodies that mimic the enzyme activity and to investigate a new strategy to produce catalytic antibodies. Anti-Tendamistat polyclonal antibodies (pAbs) were shown to cross-react with acarbose, a strong carbohydrate inhibitor of alpha-amylases, and th...

In this review, we explore recent developments in the generation of catalytic antibodies and their potential in therapy.

The -galactosidase AgaB of Bacillus stearothermophilus displays a major 1,6 and a minor 1,3 regioselectivity. The wild-type enzyme was subjected to directed evolution (random mutagenesis and in vitro recombination) using a double screening strategy based on the elimination of the 1,6 regioselectivity and the analysis by TLC of the transglycosylatio...

Alpha-galactosidase AgaB of Bacillus stearothermophilus was subjected to directed evolution in an effort to modify its regioselectivity. The wild-type enzyme displays a major 1,6 and minor 1,3 regioselectivity. We used random mutagenesis and staggered extension process (StEP) to obtain mutant enzymes displaying modified regioselectivity. We develop...

-galactosidase AgaB of Bacillus stearothermophilus was subjected to directed evolution in an effort to modify its regioselectivity. The wild-type enzyme displays a major 1,6 and minor 1,3 regioselectivity. We used random mutagenesis and staggered extension process (StEP) to obtain mutant enzymes displaying modified regioselectivity. We developed a...

The crystal structure of the complex of a catalytic antibody with its cationic hapten at 1.9-A resolution demonstrates that the hapten amidinium group is stabilized through an ionic pair interaction with the carboxylate of a combining-site residue. The location of this carboxylate allows it to act as a general base in an allylic rearrangement. When...

The catalytic antibody 4B2, which was generated against a substituted amidine 1, catalyses the allylic isomerization of beta, gamma-unsaturated ketones with an acceleration factor (k(cat)/k(uncat)) of 1.5x10(3). On the basis of the 'bait and switch' strategy, it was reasoned that the positively charged hapten could elicit, by charge complementarity...

A solid-phase assay designed for the detection of glycosidase activity has been developed which detects 5 10–4 unit of and -galactosidases in 50 L medium. The assay is highly stereo-specific. This assay is suitable for turbid or coloured fluids containing glycosidases and allows rapid and reliable Ki determination of glycosidase inhibitors. Rapid S...

With the aim of providing new methods for the regioselective protection at the 2,3 and 4 positions of monosaccharides, we have studied the acetylation of a class of rigid sugars: the 1,6-anhydro-β-D- and L-hexopyranoses (hexopyranosanes D-1 to D-5 and L-1 to L-5), using vinyl acetate as an acyl donor and two common lipases,Candida rugosa and Pseudo...

Rather efficient catalysis of the decomposition of 5-nitro-benzisoxazole to the cyanophenol was observed with antibodies elicited against a cationic hapten structurally unrelated to the benzisoxazole substrate. The rate enhancement by the most active antibody is better than 104 and the reaction is catalyzed by a carboxylate group associated with a...

The maximum entropy method (MEM) appears to be a powerful technique to analyze relaxation data. The method is robust against experimental constraints such as the signal to noise ratio and signal truncation. This method needs no assumptions for initial values and number of components. The analysis of the relaxation curve as a continuous distribution...

The conformation of two mannose-based amidines, the N-benzylmannoamidine and a pseudo (1→6) dimannoside, has been evaluated using semi-empirical AMI calculations and H NMR studies. The most stable conformations of the mannoamidine ring correspond to the half-chair forms H4 and H3. The conformations (Z) or (E) about the exocyclic C-N bond depend on...

On-line process control can often improve productivity and quality in the food industry by allowing a rapid identification of the raw materials used as ingredients and by adjusting the blending to keep the final composition of the product constant. For these reasons on-line process control is a rapidly growing branch of analytical chemistry. On-lin...

The conformational features of sucrose in the combining site of lentil lectin have been characterized through elucidation of a crystalline complex at 1.9-Å resolution, transferred nuclear Overhauser effect experiments performed at 600 Mhz, and molecular modeling. In the crystal, the lentil lectin dimer binds one sucrose molecule per monomer. The lo...

Five substituted amidines were examined as reversible inhibitors of glycosidases. All compounds exhibit competitive inhibition. The Ki values of the amidines strongly depend on the hydroxylation pattern and on the structure of the aglycon moeity. Best inhibition (Ki = 10−6-10−7 M) were observed with structures that closely resemble to sugar structu...

The synthesis of a fully hydroxylated amidine-based pseudo-saccharide is reported from D-mannonolactam. The pseudo-dimannoside is a good competitive inhibitor of α-mannosidase (Ki = 2.6 μM) and has a better selectivity than other mannoamidines.

Candida Rugosa Lipase (AY 30, Amano) is shown to be a very efficient catalyst for the resolution of enantiomeric 1,3-diaryl-1,3-diols by means of the transesterification reaction using vinyl acetate as an acyl donor. This enzyme also exerts a great diasteroselectivity and a pronounced regioselectivity in the monoacylation reaction of these diols.

The synthetic potential ofAlmond β-glucosidase andJack bean α-mannosidase in the presence of high amounts of β-mercaptoethanol as glycosyl acceptor for the synthesis of β-mercaptoethyl-glycosides was studied. The regioselectivity, O-glycosylation and/or S-glycosylation, and the stereoselectivity were analyzed with the reverse hydrolysis and the tra...

The synthesis of a substituted mannopyranose-based amidine is described and its potential as glycosidase inhibitor evaluated. This new aminosugar derivative acts as a potent glycosidase inhibitor by virtue of its charge and shape similarities to the mannopyranosyl cation. The benzyl group of this pseudodisaccharide may also contribute to enzyme tra...

Cette article propose une analyse selon la méthode de Maximisation de l'Entropie (MEM) qui permet de calculer une distribution continue d'exponentielles. Cette méthode est validée sur des données simulées et expérimentales et présente une stabilité notable vis-à-vis des conditions de mesure. Appliquée à l'analyse de signaux de relaxation d'échantil...

NMR transverse relaxation times of water were obtained in skim milk after renneting and during the syneresis of the curd. New data analysis using the maximum entropy method was applied to relaxation curves to investigate the distribution of water between the whey and the curd during the shrinkage of the milk clot. It is shown that the T-2 relaxatio...

The effects of decreasing pH and micellar calcium concentrations of reconstituted skim milk and caseinate solution were studied by 1H and 17O NMR spectroscopy. The proton transverse relaxation rate 1/T2 of skim milk decreased as the pH decreased, reaching a minimum at pH 5·3. However, as the pH fell sodium caseinate solution showed a continuous inc...

The naturally occurring peptidyl protease inhibitor leupeptin (N-acetyl-L-leucyl-L-leucyl-L-argininal) has been prepared labeled with 13C at the argininal carbonyl. 13C chemical shift data for the trypsin-leupeptin inhibitor complex in the pH range 3.0-7.6 reveal the presence of two pH-dependent covalent complexes, suggestive of two interconverting...

An integral transform technique, the Padé-Laplace method, was adopted to calculate the number of discrete exponential components and the corresponding parameters from NMR spin relaxation decay curves. The results thus obtained can be improved by injection into an iterative program. This ‘Padé-Laplace plus iterative’ method was tested on simulated d...

31P NMR technique was used to determine variations between potato varieties in the degree of phosphorylalion on the C-3 and C-6 sites of the glucosidyl units of the amylopectin molecules. The C-3 phosphorylation was independent of the potato variety, while a substantial variation in the C-6 phosphorylation was observed. Bestimmung der Phosphorylier...

Low-resolution NMR is used to determine residual sugars and alcohol content in the course of an oenological fermentation process. The measurement requires the use of a relaxation reagent (MnCl2, 1 mM) to attenuate the water proton signal. Acquisition of the signal after a spin-echo sequence permits observation of the contributions of the soluble su...

The binding of Ca2+ to membrane models composed of diplamitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine (DPPE) 15N-labeled in the polar head group was investigated at pH 8.5 and pH 9.4 by 15N-NMR spectroscopy. Both phospholipids exhibit a decrease in the chemical shift anisotropy, indicating changes of the order parameter o...

A monoclonal antibody (Ab) 19.9 specific for colorectal carcinoma was labeled with a high number of gadolinium (Gd) atoms for its potential application as a contrast agent in magnetic resonance imaging (MRI). The DTPA was conjugated to 19.9 Ab via the bicyclic DTPA anhydride method (c. DTPA) using c. DTPA/Ab molar ratios between 5 and 150. The aggr...

Low-resolution pulsed nuclear magnetic resonance may be used to determine the ethanol concentration in alcoholic beverages. The measurement is based on the J echo modulation of NMR signals for an ethanol sample, which goes through a maximum at a refocusing time of 1/(2J) equals 68 ms. A linear relationship is obtained between the percentage of etha...