Insights into the activity and specificity of trypanosoma cruzi trans -Sialidase from molecular dynamics simulations

Felicity L. Mitchell, João Neres, Anitha Ramraj, Rajesh K. Raju, Ian H. Hillier, Mark A. Vincent, Richard A. Bryce

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Trypanosoma cruzitrans-sialidase (TcTS), which catalyzes the transfer or hydrolysis of terminal sialic acid residues, is crucial to the development and proliferation of the T. cruzi parasite and thus has emerged as a potential drug target for the treatment of Chagas disease. We here probe the origin of the observed preference for the transfer reaction over hydrolysis where the substrate for TcTS is the natural sialyl donor (represented in this work by sialyllactose). Thus, acceptor lactose preferentially attacks the sialyl-enyzme intermediate rather than water. We compare this with the weaker preference for such transfer shown by a synthetic donor substrate, 4-methylumbelliferyl α-d-acetylneuraminide. For this reason, we conducted molecular dynamics simulations of TcTS following its sialylation by the substrate to examine the behavior of the asialyl leaving group by the protein. These simulations indicate that, where lactose is released, this leaving group samples well-defined interactions in the acceptor site, some of which are mediated by localized water molecules; also, the extent of the opening of the acceptor site to solvent is reduced as compared with those of unliganded forms of TcTS. However, where there is release of 4-methylumbelliferone, this leaving group explores a range of transient poses; surrounding active site water is also more disordered. The acceptor site explores more open conformations, similar to the case in which the 4-methylumbelliferone is absent. Thus, the predicted solvent accessibility of sialylated TcTS is increased when 4-methylumbelliferyl α-d- acetylneuraminide is the substrate compared to sialyllactose; this in turn is likely to contribute to a greater propensity for hydrolysis of the covalent intermediate. These computational simulations, which suggest that protein flexibility has a role in the transferase/sialidase activity of TcTS, have the potential to aid in the design of anti-Chagas inhibitors effective against this neglected tropical disease.

Original languageEnglish
Pages (from-to)3740-3751
Number of pages12
JournalBiochemistry
Volume52
Issue number21
DOIs
Publication statusPublished - 28 May 2013
Externally publishedYes

Fingerprint

Trypanosoma
Neuraminidase
Molecular Dynamics Simulation
Molecular dynamics
Computer simulation
Hymecromone
Hydrolysis
Substrates
Lactose
Water
Neglected Diseases
Chagas Disease
Trypanosoma cruzi
N-Acetylneuraminic Acid
Transferases
trans-sialidase
Conformations
Catalytic Domain
Parasites
Proteins

ASJC Scopus subject areas

  • Biochemistry

Cite this

Mitchell, F. L., Neres, J., Ramraj, A., Raju, R. K., Hillier, I. H., Vincent, M. A., & Bryce, R. A. (2013). Insights into the activity and specificity of trypanosoma cruzi trans -Sialidase from molecular dynamics simulations. Biochemistry, 52(21), 3740-3751. https://doi.org/10.1021/bi301112p

Insights into the activity and specificity of trypanosoma cruzi trans -Sialidase from molecular dynamics simulations. / Mitchell, Felicity L.; Neres, João; Ramraj, Anitha; Raju, Rajesh K.; Hillier, Ian H.; Vincent, Mark A.; Bryce, Richard A.

In: Biochemistry, Vol. 52, No. 21, 28.05.2013, p. 3740-3751.

Research output: Contribution to journalArticle

Mitchell, FL, Neres, J, Ramraj, A, Raju, RK, Hillier, IH, Vincent, MA & Bryce, RA 2013, 'Insights into the activity and specificity of trypanosoma cruzi trans -Sialidase from molecular dynamics simulations', Biochemistry, vol. 52, no. 21, pp. 3740-3751. https://doi.org/10.1021/bi301112p
Mitchell, Felicity L. ; Neres, João ; Ramraj, Anitha ; Raju, Rajesh K. ; Hillier, Ian H. ; Vincent, Mark A. ; Bryce, Richard A. / Insights into the activity and specificity of trypanosoma cruzi trans -Sialidase from molecular dynamics simulations. In: Biochemistry. 2013 ; Vol. 52, No. 21. pp. 3740-3751.
@article{9c3a4285ecc247068a92709ca50a6044,
title = "Insights into the activity and specificity of trypanosoma cruzi trans -Sialidase from molecular dynamics simulations",
abstract = "Trypanosoma cruzitrans-sialidase (TcTS), which catalyzes the transfer or hydrolysis of terminal sialic acid residues, is crucial to the development and proliferation of the T. cruzi parasite and thus has emerged as a potential drug target for the treatment of Chagas disease. We here probe the origin of the observed preference for the transfer reaction over hydrolysis where the substrate for TcTS is the natural sialyl donor (represented in this work by sialyllactose). Thus, acceptor lactose preferentially attacks the sialyl-enyzme intermediate rather than water. We compare this with the weaker preference for such transfer shown by a synthetic donor substrate, 4-methylumbelliferyl α-d-acetylneuraminide. For this reason, we conducted molecular dynamics simulations of TcTS following its sialylation by the substrate to examine the behavior of the asialyl leaving group by the protein. These simulations indicate that, where lactose is released, this leaving group samples well-defined interactions in the acceptor site, some of which are mediated by localized water molecules; also, the extent of the opening of the acceptor site to solvent is reduced as compared with those of unliganded forms of TcTS. However, where there is release of 4-methylumbelliferone, this leaving group explores a range of transient poses; surrounding active site water is also more disordered. The acceptor site explores more open conformations, similar to the case in which the 4-methylumbelliferone is absent. Thus, the predicted solvent accessibility of sialylated TcTS is increased when 4-methylumbelliferyl α-d- acetylneuraminide is the substrate compared to sialyllactose; this in turn is likely to contribute to a greater propensity for hydrolysis of the covalent intermediate. These computational simulations, which suggest that protein flexibility has a role in the transferase/sialidase activity of TcTS, have the potential to aid in the design of anti-Chagas inhibitors effective against this neglected tropical disease.",
author = "Mitchell, {Felicity L.} and Jo{\~a}o Neres and Anitha Ramraj and Raju, {Rajesh K.} and Hillier, {Ian H.} and Vincent, {Mark A.} and Bryce, {Richard A.}",
year = "2013",
month = "5",
day = "28",
doi = "10.1021/bi301112p",
language = "English",
volume = "52",
pages = "3740--3751",
journal = "Biochemistry",
issn = "0006-2960",
publisher = "American Chemical Society",
number = "21",

}

TY - JOUR

T1 - Insights into the activity and specificity of trypanosoma cruzi trans -Sialidase from molecular dynamics simulations

AU - Mitchell, Felicity L.

AU - Neres, João

AU - Ramraj, Anitha

AU - Raju, Rajesh K.

AU - Hillier, Ian H.

AU - Vincent, Mark A.

AU - Bryce, Richard A.

PY - 2013/5/28

Y1 - 2013/5/28

N2 - Trypanosoma cruzitrans-sialidase (TcTS), which catalyzes the transfer or hydrolysis of terminal sialic acid residues, is crucial to the development and proliferation of the T. cruzi parasite and thus has emerged as a potential drug target for the treatment of Chagas disease. We here probe the origin of the observed preference for the transfer reaction over hydrolysis where the substrate for TcTS is the natural sialyl donor (represented in this work by sialyllactose). Thus, acceptor lactose preferentially attacks the sialyl-enyzme intermediate rather than water. We compare this with the weaker preference for such transfer shown by a synthetic donor substrate, 4-methylumbelliferyl α-d-acetylneuraminide. For this reason, we conducted molecular dynamics simulations of TcTS following its sialylation by the substrate to examine the behavior of the asialyl leaving group by the protein. These simulations indicate that, where lactose is released, this leaving group samples well-defined interactions in the acceptor site, some of which are mediated by localized water molecules; also, the extent of the opening of the acceptor site to solvent is reduced as compared with those of unliganded forms of TcTS. However, where there is release of 4-methylumbelliferone, this leaving group explores a range of transient poses; surrounding active site water is also more disordered. The acceptor site explores more open conformations, similar to the case in which the 4-methylumbelliferone is absent. Thus, the predicted solvent accessibility of sialylated TcTS is increased when 4-methylumbelliferyl α-d- acetylneuraminide is the substrate compared to sialyllactose; this in turn is likely to contribute to a greater propensity for hydrolysis of the covalent intermediate. These computational simulations, which suggest that protein flexibility has a role in the transferase/sialidase activity of TcTS, have the potential to aid in the design of anti-Chagas inhibitors effective against this neglected tropical disease.

AB - Trypanosoma cruzitrans-sialidase (TcTS), which catalyzes the transfer or hydrolysis of terminal sialic acid residues, is crucial to the development and proliferation of the T. cruzi parasite and thus has emerged as a potential drug target for the treatment of Chagas disease. We here probe the origin of the observed preference for the transfer reaction over hydrolysis where the substrate for TcTS is the natural sialyl donor (represented in this work by sialyllactose). Thus, acceptor lactose preferentially attacks the sialyl-enyzme intermediate rather than water. We compare this with the weaker preference for such transfer shown by a synthetic donor substrate, 4-methylumbelliferyl α-d-acetylneuraminide. For this reason, we conducted molecular dynamics simulations of TcTS following its sialylation by the substrate to examine the behavior of the asialyl leaving group by the protein. These simulations indicate that, where lactose is released, this leaving group samples well-defined interactions in the acceptor site, some of which are mediated by localized water molecules; also, the extent of the opening of the acceptor site to solvent is reduced as compared with those of unliganded forms of TcTS. However, where there is release of 4-methylumbelliferone, this leaving group explores a range of transient poses; surrounding active site water is also more disordered. The acceptor site explores more open conformations, similar to the case in which the 4-methylumbelliferone is absent. Thus, the predicted solvent accessibility of sialylated TcTS is increased when 4-methylumbelliferyl α-d- acetylneuraminide is the substrate compared to sialyllactose; this in turn is likely to contribute to a greater propensity for hydrolysis of the covalent intermediate. These computational simulations, which suggest that protein flexibility has a role in the transferase/sialidase activity of TcTS, have the potential to aid in the design of anti-Chagas inhibitors effective against this neglected tropical disease.

UR - http://www.scopus.com/inward/record.url?scp=84878342023&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84878342023&partnerID=8YFLogxK

U2 - 10.1021/bi301112p

DO - 10.1021/bi301112p

M3 - Article

VL - 52

SP - 3740

EP - 3751

JO - Biochemistry

JF - Biochemistry

SN - 0006-2960

IS - 21

ER -