References of "Dive, Georges"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailSynthèse, étude théorique et évaluation biologique de dérivés du 4-amino-4H-1,2,4-triazole analogues des antibiotiques b-lactamiques
Pirotte, Bernard ULg; Dive, Georges ULg; Delarge, Jacques et al

in European Journal of Medicinal Chemistry (1992), 27(3), 193-205

Detailed reference viewed: 31 (8 ULg)
Full Text
Peer Reviewed
See detailMechanism of acyl transfer by the class A serine β-lactamase of Streptomyces albus G
Lamotte-Brasseur, Josette; Dive, Georges ULg; Dideberg, Otto et al

in Biochemical Journal (1991), 279(Pt 1), 213-221

Optimization by energy minimization of stable complexes occurring along the pathway of hydrolysis of benzylpenicillin and cephalosporin C by the Streptomyces albus G beta-lactamase has highlighted a ... [more ▼]

Optimization by energy minimization of stable complexes occurring along the pathway of hydrolysis of benzylpenicillin and cephalosporin C by the Streptomyces albus G beta-lactamase has highlighted a proton shuttle that may explain the catalytic mechanism of the beta-lactamases of class A. Five residues, S70, S130, N132, T235 and A237, are involved in ligand binding. The gamma-OH group of T235 and, in the case of benzylpenicillin, the gamma-OH group of S130 interact with the carboxylate group, on one side of the ligand molecule. The side-chain NH2 group of N132 and the carbonyl backbone of A237 interact with the exocyclic CONH amide bond, on the other side of the ligand. The backbone NH groups of S70 and A237 polarize the carbonyl group of the scissile beta-lactam amide bond. Four residues, S70, K73, S130 and E166, and two water molecules, W1 and W2, perform hydrolysis of the bound beta-lactam compound. E166, via W1, abstracts the proton from the gamma-OH group of S70. While losing its proton, the O-gamma atom of S70 attacks the carbonyl carbon atom of the beta-lactam ring and, concomitantly, the proton is delivered back to the adjacent nitrogen atom via W2, K73 and S130, thus achieving formation of the acyl-enzyme. Subsequently, E166 abstracts a proton from W1. While losing its proton, W1 attacks the carbonyl carbon atom of the S70 ester-linked acyl-enzyme and, concomitantly, re-entry of a water molecule W'1 replacing W1 allows E166 to deliver the proton back to the same carbonyl carbon atom, thus achieving hydrolysis of the beta-lactam compound and enzyme recovery. The model well explains the differences found in the kcat. values for hydrolysis of benzylpenicillin and cephalosporin C by the Streptomyces albus G beta-lactamase. It also explains the effects caused by site-directed mutagenesis of the Bacillus cereus beta-lactamase I [Gibson, Christensen [less ▲]

Detailed reference viewed: 19 (2 ULg)
Peer Reviewed
See detailThe Importance of the Negative Charge of Beta-Lactam Compounds in the Interactions with Active-Site Serine Dd-Peptidases and Beta-Lactamases
Varetto, Louis ULg; De Meester, Fabien; Monnaie, Didier et al

in Biochemical Journal (1991), 278(Pt 3), 801-807

The interaction between various penicillins and cephalosporins the carboxylate group of which at C-3 or C-4 had been esterified or amidated and different penicillin-recognizing enzymes was studied. In ... [more ▼]

The interaction between various penicillins and cephalosporins the carboxylate group of which at C-3 or C-4 had been esterified or amidated and different penicillin-recognizing enzymes was studied. In general, our findings reinforced the common assumption that an anionic group at that position is necessary for the effective acylation of these enzymes. However, the relative activities of the modified beta-lactams as inactivators of the Streptomyces R61 DD-peptidase or as substrates of the Bacillus licheniformis, Streptomyces albus G and Enterobacter cloacae beta-lactamases did not fit a general scheme in which the intrinsic electronic and geometric properties of the beta-lactam compounds would be sufficient to explain their substrate or inactivator properties towards the various types of enzymes investigated. [less ▲]

Detailed reference viewed: 16 (2 ULg)
Peer Reviewed
See detailPaf-Receptor. iii. Conformational and Electronic Properties of Paf-Like Agonists and Antagonists
Lamotte-Brasseur, Josette; Dive, Georges ULg; Lamouri, Aazdine et al

in Biochimica et Biophysica Acta (1991), 1085(1), 91-105

In order to compare electronic and conformational properties of PAF-agonists and PAF-antagonists, 14 analogues structurally related to PAF were studied. A common conformation of the glycerol backbone was ... [more ▼]

In order to compare electronic and conformational properties of PAF-agonists and PAF-antagonists, 14 analogues structurally related to PAF were studied. A common conformation of the glycerol backbone was present in all agonists and all constrained or flexible antagonists. The distinction between agonists and antagonists appears to be casted on position-2 where the folded conformation of the substituent for agonists should be the most probable. In position-3 the gauche conformation can be adopted by all the analysed compounds. The electrostatic potential well at -30 kcal/mol stretches to the carbonyl group in position-2 in the folded conformation of the agonists. On the contrary, in constrained antagonists, a second negative zone appears around the carbamate group. Given the modelling results, the triethylammonium PAF analogue considered in literature as a weak agonist, was resynthesized and proved to be more potent than previously reported. These experimental results confirm our hypothesis in terms of a common conformation of agonist and antagonist PAF-like molecules. [less ▲]

Detailed reference viewed: 15 (1 ULg)
Full Text
Peer Reviewed
See detailPolarization correction to the electrostatic potential at the CNDO and the ab initio level. Influence of the basis set expansion
Dehareng, Dominique ULg; Dive, Georges ULg; Ghuysen, Jean-Marie ULg

in Theoretica Chimica Acta (1991), 79(2), 141-152

The influence of the basis set on the electrostatic potential corrected for polarization has been studied for H2S, CH3SH and COHCH2SH. The position and deepness of the minima and the height of the barrier ... [more ▼]

The influence of the basis set on the electrostatic potential corrected for polarization has been studied for H2S, CH3SH and COHCH2SH. The position and deepness of the minima and the height of the barrier between symmetric minima is discussed at both the deorthogonalized CNDO/2 and ab initio levels within STO-3G, 3-21G, 4-31G, 6-31G and 6-311G basis sets. The calculation of the electrostatic potential and corrected one using CNDO deorthogonalized coefficients including 3d orbitals has been applied at the first time on sulfur-containing molecules. The influence of polarization and diffuse functions has also been analysed and the incidence of the polarization correction on the relative proton affinity in NH2(CH2)3NHCH3 and in the adenine molecule has been investigated at the CNDO and ab initio levels. At both levels, the relative proton affinity of several basic sites in the same molecule can be qualitatively expressed without inclusion of the polarization correction except in the case of substituted amines. [less ▲]

Detailed reference viewed: 16 (2 ULg)
Full Text
Peer Reviewed
See detailConformational analysis of β and γ-lactam antibiotics
Lamotte, Josette ULg; Dive, Georges ULg; Ghuysen, Jean-Marie ULg

in European Journal of Medicinal Chemistry (1991), 26(1), 43-50

Geometry optimization, superimposition searches and conformational analysis carried on several lactam antibiotics show that reactivity with the active-site serine penicillin-binding proteins is related to ... [more ▼]

Geometry optimization, superimposition searches and conformational analysis carried on several lactam antibiotics show that reactivity with the active-site serine penicillin-binding proteins is related to a particular spatial disposition of 2 flanking functional groups - namely a C = O or C-OH on 1 side and a carboxylate on the other - with respect to the central scissile amide bond. Such a binding entity is found in one of the most stable conformers of the tripeptide diacetyl-L-Lys-D-Ala-D-Ala conferring substrate activity, and in benzylpenicillin, cephapyrin, thienamycin, gamma-lactam, the 6-spiro-epoxypenicillin S and in one epimer of lactivicin, conferring inactivating potency. This binding entity generates a particular electronic distribution and the fact that it is conserved in compounds belonging to very different chemical families strongly suggests that it is an important feature required for enzyme recognition. [less ▲]

Detailed reference viewed: 105 (6 ULg)
Full Text
Peer Reviewed
See detailNew alkoxypyridine Sulfonamides: Synthesis, Biological Evaluation and Physicochemical Properties
Liégeois, Jean-François ULg; Dive, Georges ULg; Dupont, Léon et al

in Helvetica Chimica Acta (1991), 74(8), 1764-1772

Detailed reference viewed: 24 (4 ULg)
Peer Reviewed
See detailPAF receptor structure: a hypothesis
Godfroid, Jean-Jacques; Dive, Georges ULg; Lamotte-Brasseur, Josette et al

in Lipids (1991), 26(12), 1162-1166

Detailed reference viewed: 9 (2 ULg)
Peer Reviewed
See detailPAF receptor and cache-oreilles effect. Simple PAF antagonists
Lamotte-Brasseur, Josette; Heymans, Françoise; Dive, Georges ULg et al

in Lipids (1991), 26(12), 1167-1171

Detailed reference viewed: 9 (2 ULg)
Peer Reviewed
See detailAsymmetric Diels-Alder reactions of a nitroso compound derived from D-bornane-10,2-sultam
Gouverneur, Véronique; Dive, Georges ULg; Ghosez, Léon

in Tetrahedron, Asymmetry (1991), 2(12), 1173-1176

Detailed reference viewed: 14 (2 ULg)
Peer Reviewed
See detailNew hypothesis on the conformation of the PAF receptor from studies on the geometry of selected platelet-activating-factor antagonists
Batt, Jean-Pierre; Lamouri, Aazdine; Tavet, Fabrice et al

in Journal of Lipid Mediators (1991), 4(3), 343-346

Detailed reference viewed: 10 (1 ULg)
Full Text
Peer Reviewed
See detailElectrostatic potential maps at the quantum chemistry level of the active sites of the serine peptidases, α-chymotrypsin and subtilisin
Lamotte-Brasseur, Josette; Dive, Georges ULg; Dehareng, Dominique ULg et al

in Journal of Theoretical Biology (1990), 145(2), 183-98

The electronic properties of the active-sites of the structurally unrelated serine peptidases, alpha-chymotrypsin and subtilisin, have been expressed in the form of three-dimensional electrostatic ... [more ▼]

The electronic properties of the active-sites of the structurally unrelated serine peptidases, alpha-chymotrypsin and subtilisin, have been expressed in the form of three-dimensional electrostatic potential maps derived from integrals calculated at the quantum chemistry level. As a consequence of the asymmetrical distribution of the secondary structures that occur within a 7 A sphere around the serine of the catalytic triad, the active sites are highly polarized entities and exhibit large dipole moments. One part of the active sites generates a nucleophilic suction-pump. Its isocontour at -10 kcal mol-1 defines an impressive, negatively-charged volume which bears a narrow channel in the immediate vicinity of the active-site serine 195 in alpha-chymotrypsin or 221 in subtilisin. In native alpha-chymotrypsin, there is a perfect complementation between this nucleophilic suction-pump and the positively-charged electrophilic hole that is generated by the backbone NH of Ser 195 and Gly 193. In subtilisin, generation of the complementing electrophilic hole requires binding of a carbonyl donor ligand and may be achieved by rotation of the side-chain amide of Asn 155 towards the backbone NH of Ser 221. Small variations in the atomic co-ordinates of alpha-chymotrypsin used for the calculations, the presence of water molecules in its active site and the occurrence of point mutations in the amino acid sequence of subtilisin have little effects on the shape and characteristics of the electrostatic potential. [less ▲]

Detailed reference viewed: 27 (11 ULg)
Full Text
Peer Reviewed
See detailThe Life-Cycle Proteins Roda of Escherichia Coli and Spove of Bacillus Subtilis Have Very Similar Primary Structures
Joris, Bernard ULg; Dive, Georges ULg; Henriques, A. et al

in Molecular Microbiology (1990), 4(3), 513-517

Comparison of the predicted amino acid sequence of the cell-cycle RodA protein with the National Research Foundation protein sequence database shows that the 370-amino-acid RodA, a protein that is ... [more ▼]

Comparison of the predicted amino acid sequence of the cell-cycle RodA protein with the National Research Foundation protein sequence database shows that the 370-amino-acid RodA, a protein that is essential for wall elongation in Escherichia coli and maintenance of the rod shape of the cell, is highly analogous, in terms of primary structure, with the Bacillus subtilis SpoVE protein involved in stage V of sporulation. [less ▲]

Detailed reference viewed: 44 (2 ULg)
Full Text
Peer Reviewed
See detailUnexpected Influence of Ionic Strength on Branched-Pathway Interactions between Beta-Lactamases and Beta-Halogenopenicillanates
De Meester, F.; Matagne, André ULg; Dive, Georges ULg et al

in Biochemical Journal (1989), 257(1), 245-9

Ionic strength strongly influenced the turnover/inactivation ratio in the interaction between beta-halogenopenicillanates and some class A beta-lactamases. This suggested the stabilization of a highly ... [more ▼]

Ionic strength strongly influenced the turnover/inactivation ratio in the interaction between beta-halogenopenicillanates and some class A beta-lactamases. This suggested the stabilization of a highly charged intermediate by solvation. Those data could be interpreted on the basis of a reaction pathway where an episulphonium ion was transiently formed. The various mechanisms proposed for explaining the formation of the dihydrothiazine chromophore are discussed. [less ▲]

Detailed reference viewed: 3 (1 ULg)
Full Text
Peer Reviewed
See detailNumerical computation of the electrostatic interaction energy between methanol and the dyad water-imidazole
Dehareng, Dominique ULg; Dive, Georges ULg; Lamotte-Brasseur, Josette ULg et al

in Theoretica Chimica Acta (1989), 76(2), 85-94

The electrostatic interaction energy between methanol and the dyad water-imidazole has been computed numerically at three levels of approximation from 3D grids of the charge density of one partner and the ... [more ▼]

The electrostatic interaction energy between methanol and the dyad water-imidazole has been computed numerically at three levels of approximation from 3D grids of the charge density of one partner and the electrostatic potential of the other. The minimum positions and energy values thus obtained compare well with those calculated analytically. The numerical procedure is especially interesting for the prediction of the stable conformers. [less ▲]

Detailed reference viewed: 19 (3 ULg)
Peer Reviewed
See detailPaf-Receptor. 1. 'Cache-Oreilles' Effect of Selected High-Potency Platelet-Activating Factor (Paf) Antagonists
Dive, Georges ULg; Godfroid, Jean-Jacques; Lamotte-Brasseur, Josette et al

in Journal of Lipid Mediators (1989), 1(4, Jul-Aug), 201-15

Three-dimensional electrostatic maps were calculated for six potent antagonists of platelet-activating factor (PAF), the antagonists being selected for their apparent structural heterogeneity. The ... [more ▼]

Three-dimensional electrostatic maps were calculated for six potent antagonists of platelet-activating factor (PAF), the antagonists being selected for their apparent structural heterogeneity. The molecules examined were the compact Ginkgolides BN 52020, BN 52021 and BN 52022 (1, 2 and 3), the semi-rigid kadsurenone (4), a flexible synthetic dinor type C furanoid lignan L-652,731 (5a) and the triazolothienobenzodiazepine WEB 2086 (7). Calculation of the electrostatic potential generated around all the above molecules showed the existence of two wells of negative potential or 'cache-oreilles' (ear-muffs), i.e., the isocontours drawn at -10 kcal/mol, located at 180 degrees from each other and separated by a maximum distance of 22-27 A. Except for the synthetic dinor type C furanoid lignan (5a), the molecules also presented a moderate hydrophobic fragment, which constitutes a third point of interaction with the high-affinity binding site in rabbit and human platelets. The findings of the present study allow speculation that this high-affinity acceptor site may be a 'polarized cylinder' with a diameter of 10-12 A. [less ▲]

Detailed reference viewed: 17 (0 ULg)
Full Text
Peer Reviewed
See detailThe Active-Site-Serine Penicillin-Recognizing Enzymes as Members of the Streptomyces R61 Dd-Peptidase Family
Joris, Bernard ULg; Ghuysen, Jean-Marie ULg; Dive, Georges ULg et al

in Biochemical Journal (1988), 250(2), 313-324

Homology searches and amino acid alignments, using the Streptomyces R61 DD-peptidase/penicillin-binding protein as reference, have been applied to the beta-lactamases of classes A and C, the Oxa-2 beta ... [more ▼]

Homology searches and amino acid alignments, using the Streptomyces R61 DD-peptidase/penicillin-binding protein as reference, have been applied to the beta-lactamases of classes A and C, the Oxa-2 beta-lactamase (considered as the first known member of an additional class D), the low-Mr DD-peptidases/penicillin-binding proteins (protein no. 5 of Escherichia coli and Bacillus subtilis) and penicillin-binding domains of the high-Mr penicillin-binding proteins (PBP1A, PBP1B, PBP2 and PBP3 of E. coli). Though the evolutionary distance may vary considerably, all these penicillin-interactive proteins and domains appear to be members of a single superfamily of active-site-serine enzymes distinct from the classical trypsin or subtilisin families. The amino acid alignments reveal several conserved boxes that consist of strict identities or homologous amino acids. The significance of these boxes is highlighted by the known results of X-ray crystallography, chemical derivatization and site-directed-mutagenesis experiments. [less ▲]

Detailed reference viewed: 37 (3 ULg)
Peer Reviewed
See detailBiotechnologie et chimie théorique
Dive, Georges ULg

in Nouvelles de la Science et des Technologies (1988), 6(1), 49-55

Detailed reference viewed: 8 (1 ULg)
Peer Reviewed
See detailMolecular graphics software on a raster
Lamotte, Josette; Dive, Georges ULg; Dehareng, Dominique et al

in Journal of Molecular Graphics (1988), 6(4), 221

Detailed reference viewed: 11 (3 ULg)
Peer Reviewed
See detailRepresentation of energetic and electronic properties in enzymatic reaction pathways
Dive, Georges ULg; Lamotte-Brasseur, Josette; Reckinger, Georges et al

in Journal of Molecular Graphics (1986), 4(4), 226

Detailed reference viewed: 4 (1 ULg)