Vinh TRAN
Professeur émérite Université
- octobre 2019
| Équipe : |
Publications
1 publication
Hendrickx, Johann; Tran, Vinh; Sanejouand, Yves-Henri
Numerous severely twisted N-acetylglucosamine conformations found in the protein databank Article de journal
Dans: Proteins: Structure, Function and Bioinformatics, vol. 88, no. 10, p. 1376–1383, 2020, ISSN: 10970134.
@article{Hendrickx2020,
title = {Numerous severely twisted N-acetylglucosamine conformations found in the protein databank},
author = {Johann Hendrickx and Vinh Tran and Yves-Henri Sanejouand},
doi = {10.1002/prot.25957},
issn = {10970134},
year = {2020},
date = {2020-01-01},
journal = {Proteins: Structure, Function and Bioinformatics},
volume = {88},
number = {10},
pages = {1376--1383},
abstract = {Taking advantage of the known planarity of the N-acetyl group of N-acetylglucosamine, an analysis of the quality of carbohydrate structures found in the protein databank was performed. Few obvious defects of the local geometry of the carbonyl group were observed. However, the N-acetyl group was often found in the less favorable cis conformation (12% of the cases). It was also found severely twisted in numerous instances, especially in structures with a resolution poorer than 1.9 Å determined between 2000 and 2015. Though the automated PDB-REDO procedure has proved able to improve nearly 85% of the structural models deposited to the PDB, and does prove able to cure most severely twisted conformations of the N-acetyl group, it fails to correct its high rate of cis conformations. More generally, for structures with a resolution poorer than 1.6 Å, it produces N-acetylglucosamine models in slightly poorer agreement with experimental data, as measured using real-space correlation coefficients. Significant improvements are thus still needed, at least as far as this carbohydrate structure is concerned.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Taking advantage of the known planarity of the N-acetyl group of N-acetylglucosamine, an analysis of the quality of carbohydrate structures found in the protein databank was performed. Few obvious defects of the local geometry of the carbonyl group were observed. However, the N-acetyl group was often found in the less favorable cis conformation (12% of the cases). It was also found severely twisted in numerous instances, especially in structures with a resolution poorer than 1.9 Å determined between 2000 and 2015. Though the automated PDB-REDO procedure has proved able to improve nearly 85% of the structural models deposited to the PDB, and does prove able to cure most severely twisted conformations of the N-acetyl group, it fails to correct its high rate of cis conformations. More generally, for structures with a resolution poorer than 1.6 Å, it produces N-acetylglucosamine models in slightly poorer agreement with experimental data, as measured using real-space correlation coefficients. Significant improvements are thus still needed, at least as far as this carbohydrate structure is concerned.
3 publications
Le-Bail, Patricia; Lorentz, C; Pencreac'h, G; Soultani-Vigneron, S; Pontoire, B; Giraldo, J. López L; Villeneuve, P; Hendrickx, Johann; Tran, Vinh
Trapping by amylose of the aliphatic chain grafted onto chlorogenic acid: Importance of the graft position Article de journal
Dans: Carbohydrate Polymers, vol. 117, p. 910–916, 2015, ISSN: 01448617.
@article{Le-Bail2015,
title = {Trapping by amylose of the aliphatic chain grafted onto chlorogenic acid: Importance of the graft position},
author = {Patricia Le-Bail and C Lorentz and G Pencreac'h and S Soultani-Vigneron and B Pontoire and J.López L Giraldo and P Villeneuve and Johann Hendrickx and Vinh Tran},
url = {http://dx.doi.org/10.1016/j.carbpol.2014.10.029},
doi = {10.1016/j.carbpol.2014.10.029},
issn = {01448617},
year = {2015},
date = {2015-01-01},
journal = {Carbohydrate Polymers},
volume = {117},
pages = {910--916},
publisher = {Elsevier Ltd.},
abstract = {5-Caffeoylquinic acid (chlorogenic acid), is classified in acid-phenols family and as polyphenolic compounds it possesses antioxidant activity. The oxydative modification of chlorogenic acid in foods may lead to alteration of their qualities; to counteract these degradation effects, molecular encapsulation was used to protect chlorogenic acid. Amylose can interact strongly with a number of small molecules, including lipids. In order to enable chlorogenic acid complexation by amylose, a C16 aliphatic chain was previously grafted onto the cycle of quinic acid. This work showed that for the two lipophilic derivatives of chlorogenic acid: hexadecyl chlorogenate obtained by alkylation and 3-O-palmitoyl chlorogenic acid obtained by acylation; only the 3-O-palmitoyl chlorogenic acid complexed amylose. The chlorogenic acid derivatives were studied by X-ray diffraction, differential scanning calorimetry and NMR to elucidate the interaction. By comparing the results with previous work on the complexation of amylose by 4-O-palmitoyl chlorogenic acid, the importance of the aliphatic chain position on the cycle of the quinic acid is clearly highlighted. A study in molecular modeling helped to understand the difference in behavior relative to amylose of these three derivatives of chlorogenic acid.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
5-Caffeoylquinic acid (chlorogenic acid), is classified in acid-phenols family and as polyphenolic compounds it possesses antioxidant activity. The oxydative modification of chlorogenic acid in foods may lead to alteration of their qualities; to counteract these degradation effects, molecular encapsulation was used to protect chlorogenic acid. Amylose can interact strongly with a number of small molecules, including lipids. In order to enable chlorogenic acid complexation by amylose, a C16 aliphatic chain was previously grafted onto the cycle of quinic acid. This work showed that for the two lipophilic derivatives of chlorogenic acid: hexadecyl chlorogenate obtained by alkylation and 3-O-palmitoyl chlorogenic acid obtained by acylation; only the 3-O-palmitoyl chlorogenic acid complexed amylose. The chlorogenic acid derivatives were studied by X-ray diffraction, differential scanning calorimetry and NMR to elucidate the interaction. By comparing the results with previous work on the complexation of amylose by 4-O-palmitoyl chlorogenic acid, the importance of the aliphatic chain position on the cycle of the quinic acid is clearly highlighted. A study in molecular modeling helped to understand the difference in behavior relative to amylose of these three derivatives of chlorogenic acid.
Saumonneau, Amélie; Champion, Elise; Peltier-Pain, Pauline; Molnar-Gabor, Dora; Hendrickx, Johann; Tran, Vinh; Hederos, Markus; Dekany, Gyula; Tellier, Charles
Design of an α-l-transfucosidase for the synthesis of fucosylated HMOs Article de journal
Dans: Glycobiology, vol. 26, no. 3, p. 261–269, 2015, ISSN: 14602423.
@article{Saumonneau2015a,
title = {Design of an α-l-transfucosidase for the synthesis of fucosylated HMOs},
author = {Amélie Saumonneau and Elise Champion and Pauline Peltier-Pain and Dora Molnar-Gabor and Johann Hendrickx and Vinh Tran and Markus Hederos and Gyula Dekany and Charles Tellier},
doi = {10.1093/glycob/cwv099},
issn = {14602423},
year = {2015},
date = {2015-01-01},
journal = {Glycobiology},
volume = {26},
number = {3},
pages = {261--269},
abstract = {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 into the glycoside hydrolase GH29 and GH95 families. The GH29 family fucosidases display a classic retaining mechanism and are good candidates for transfucosidase activity. We recently demonstrated that the α-l-fucosidase from Thermotoga maritima (TmαFuc) from the GH29 family can be evolved into an efficient transfucosidase by directed evolution (Osanjo et al. 2007). In this work, we developed semi-rational approaches to design an α-l-transfucosidase starting with the α-l-fucosidase from commensal bacteria Bifidobacterium longum subsp. infantis (BiAfcB, Blon-2336). Efficient fucosylation was obtained with enzyme mutants (L321P-BiAfcB and F34I/L321P-BiAfcB) enabling in vitro synthesis of lactodifucotetraose, lacto-N-fucopentaose II, lacto-N-fucopentaose III and lacto-N-difucohexaose I. The enzymes also generated more complex HMOs like fucosylated para-lacto-N-neohexaose (F-p-LNnH) and mono- or difucosylated lacto-N-neohexaose (F-LNnH-I, F-LNnH-II and DF-LNnH). It is worth noting that mutation at these two positions did not result in a strong decrease in the overall activity of the enzyme, which makes these variants interesting candidates for large-scale transfucosylation reactions. For the first time, this work provides an efficient enzymatic method to synthesize the majority of fucosylated HMOs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
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 into the glycoside hydrolase GH29 and GH95 families. The GH29 family fucosidases display a classic retaining mechanism and are good candidates for transfucosidase activity. We recently demonstrated that the α-l-fucosidase from Thermotoga maritima (TmαFuc) from the GH29 family can be evolved into an efficient transfucosidase by directed evolution (Osanjo et al. 2007). In this work, we developed semi-rational approaches to design an α-l-transfucosidase starting with the α-l-fucosidase from commensal bacteria Bifidobacterium longum subsp. infantis (BiAfcB, Blon-2336). Efficient fucosylation was obtained with enzyme mutants (L321P-BiAfcB and F34I/L321P-BiAfcB) enabling in vitro synthesis of lactodifucotetraose, lacto-N-fucopentaose II, lacto-N-fucopentaose III and lacto-N-difucohexaose I. The enzymes also generated more complex HMOs like fucosylated para-lacto-N-neohexaose (F-p-LNnH) and mono- or difucosylated lacto-N-neohexaose (F-LNnH-I, F-LNnH-II and DF-LNnH). It is worth noting that mutation at these two positions did not result in a strong decrease in the overall activity of the enzyme, which makes these variants interesting candidates for large-scale transfucosylation reactions. For the first time, this work provides an efficient enzymatic method to synthesize the majority of fucosylated HMOs.
André-Miral, Corinne; Koné, Fankroma Mt; Solleux, Claude; Grandjean, Cyrille; Dion, Michel; Tran, Vinh; Tellier, Charles
De novo design of a trans-β-N-acetylglucosaminidase activity from a GH1 β-glycosidase by mechanism engineering Article de journal
Dans: Glycobiology, vol. 25, no. 4, p. 394–402, 2015, ISSN: 14602423.
@article{Andre-Miral2015,
title = {De novo design of a trans-β-N-acetylglucosaminidase activity from a GH1 β-glycosidase by mechanism engineering},
author = {Corinne André-Miral and Fankroma Mt Koné and Claude Solleux and Cyrille Grandjean and Michel Dion and Vinh Tran and Charles Tellier},
doi = {10.1093/glycob/cwu121},
issn = {14602423},
year = {2015},
date = {2015-01-01},
journal = {Glycobiology},
volume = {25},
number = {4},
pages = {394--402},
abstract = {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 better the structure/function relationships of these enzymes and their evolution and to develop new robust evolved glycosidases, we undertook to convert a Family 1 thermostable β-glycosidase into an exo-β-N-acetylglucosaminidase. This latter activity is totally absent in Family 1, while natural β-hexosaminidases belong to CAZy Families 3, 20 and 84. Using molecular modeling, we first showed that the docking of N-acetyl-d-glucosamine in the subsite -1 of the β-glycosidase from Thermus thermophilus (TtβGly) suggested several steric conflicts with active site amino-acids (N163, E338) induced by the N-acetyl group. Both N163A and N163D-E338G mutations induced significant N-acetylglucosaminidase activity in TtβGly. The double mutant N163D-E338G was also active on the bicyclic oxazoline substrate, suggesting that this mutated enzyme uses a catalytic mechanism involving a substrate-assisted catalysis with a noncovalent oxazoline intermediate, similar to the N-acetylglucosaminidases from Families 20 and 84. Furthermore, a very efficient trans-N-acetylglucosaminidase activity was observed when the double mutant was incubated in the presence of NAG-oxazoline as a donor and N-methyl-O-benzyl-N-(β-d-glucopyranosyl)-hydroxylamine as an acceptor. More generally, this work demonstrates that it is possible to exchange the specificities and catalytic mechanisms with minimal changes between phylogenetically distant protein structures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
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 better the structure/function relationships of these enzymes and their evolution and to develop new robust evolved glycosidases, we undertook to convert a Family 1 thermostable β-glycosidase into an exo-β-N-acetylglucosaminidase. This latter activity is totally absent in Family 1, while natural β-hexosaminidases belong to CAZy Families 3, 20 and 84. Using molecular modeling, we first showed that the docking of N-acetyl-d-glucosamine in the subsite -1 of the β-glycosidase from Thermus thermophilus (TtβGly) suggested several steric conflicts with active site amino-acids (N163, E338) induced by the N-acetyl group. Both N163A and N163D-E338G mutations induced significant N-acetylglucosaminidase activity in TtβGly. The double mutant N163D-E338G was also active on the bicyclic oxazoline substrate, suggesting that this mutated enzyme uses a catalytic mechanism involving a substrate-assisted catalysis with a noncovalent oxazoline intermediate, similar to the N-acetylglucosaminidases from Families 20 and 84. Furthermore, a very efficient trans-N-acetylglucosaminidase activity was observed when the double mutant was incubated in the presence of NAG-oxazoline as a donor and N-methyl-O-benzyl-N-(β-d-glucopyranosyl)-hydroxylamine as an acceptor. More generally, this work demonstrates that it is possible to exchange the specificities and catalytic mechanisms with minimal changes between phylogenetically distant protein structures.
2014
Teze, David; Hendrickx, Johann; Czjzek, Mirjam; Ropartz, David; Sanejouand, Yves-Henri; Tran, Vinh; Tellier, Charles; Dion, Michel
Semi-rational approach for converting a GH1 ß-glycosidase into a ß-transglycosidase Article de journal
Dans: Protein Engineering, Design & Selection, vol. 27, no. 1, p. 13–19, 2014.
@article{teze2014semi,
title = {Semi-rational approach for converting a GH1 ß-glycosidase into a ß-transglycosidase},
author = {David Teze and Johann Hendrickx and Mirjam Czjzek and David Ropartz and Yves-Henri Sanejouand and Vinh Tran and Charles Tellier and Michel Dion},
doi = {10.1093/protein/gzt057},
year = {2014},
date = {2014-01-01},
urldate = {2014-01-01},
journal = {Protein Engineering, Design & Selection},
volume = {27},
number = {1},
pages = {13--19},
publisher = {Oxford University Press},
abstract = {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, glycoside hydrolase family 1 (GH1)), which display a higher transglycosylation/hydrolysis ratio than the wild-type enzyme. In order to find the cause of these activity modifications, and thereby set up a generic method for easily obtaining transglycosidases from glycosidases, we determined their X-ray structure. No major structural changes could be observed which could help to rationalize the mutagenesis of glycosidases into transglycosidases. However, as these mutations are highly conserved in GH1 β-glycosidases and are located around the −1 site, we pursued the isolation of new transglycosidases by targeting highly conserved amino acids located around the active site. Thus, by single-point mutagenesis on Ttβ-gly, we created four new mutants that exhibit improved synthetic activity, producing disaccharides in yields of 68–90% against only 36% when native Ttβ-gly was used. As all of the chosen positions were well conserved among GH1 enzymes, this approach is most probably a general route to convert GH1 glycosidases into transglycosidases.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
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, glycoside hydrolase family 1 (GH1)), which display a higher transglycosylation/hydrolysis ratio than the wild-type enzyme. In order to find the cause of these activity modifications, and thereby set up a generic method for easily obtaining transglycosidases from glycosidases, we determined their X-ray structure. No major structural changes could be observed which could help to rationalize the mutagenesis of glycosidases into transglycosidases. However, as these mutations are highly conserved in GH1 β-glycosidases and are located around the −1 site, we pursued the isolation of new transglycosidases by targeting highly conserved amino acids located around the active site. Thus, by single-point mutagenesis on Ttβ-gly, we created four new mutants that exhibit improved synthetic activity, producing disaccharides in yields of 68–90% against only 36% when native Ttβ-gly was used. As all of the chosen positions were well conserved among GH1 enzymes, this approach is most probably a general route to convert GH1 glycosidases into transglycosidases.