Probing the substrate specificity of Trypanosoma brucei GlcNAc-PI de-N-acetylase with synthetic substrate analogues

Capes, Amy S. and Crossman, Arthur and Urbaniak, Michael D. and Gilbert, Sophie H. and Ferguson, Michael A. J. and Gilbert, Ian H. (2014) Probing the substrate specificity of Trypanosoma brucei GlcNAc-PI de-N-acetylase with synthetic substrate analogues. Organic and Biomolecular Chemistry, 2014 (12). pp. 1919-1934. ISSN 1477-0520

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Abstract

A series of synthetic analogues of 1-d-(2-amino-2-deoxy-α-d-glucopyranosyl)-myo-inositol 1-(1,2-di-O-hexadecanoyl-sn-glycerol 3-phosphate), consisting of 7 variants of either the d-myo-inositol, d-GlcpN or the phospholipid components, were prepared and tested as substrates and inhibitors of GlcNAc-PI de-N-acetylase, a genetically validated drug target enzyme responsible for the second step in the glycosylphosphatidylinositol (GPI) biosynthetic pathway of Trypanosoma brucei. The d-myo-inositol in the physiological substrate was successfully replaced by cyclohexanediol and is still a substrate for T. brucei GlcNAc-PI de-N-acetylase. However, this compound became sensitive to the stereochemistry of the glycoside linkage (the β-anomer was neither substrate or inhibitor) and the structure of the lipid moiety (the hexadecyl derivatives were inhibitors). Chemistry was successfully developed to replace the phosphate with a sulphonamide, but the compound was neither a substrate or an inhibitor, confirming the importance of the phosphate for molecular recognition. We also replaced the glucosamine by an acyclic analogue, but this also was inactive, both as a substrate and inhibitor. These findings add significantly to our understanding of substrate and inhibitor binding to the GlcNAc-PI de-N-acetylase enzyme and will have a bearing on the design of future inhibitors.

Item Type:
Journal Article
Journal or Publication Title:
Organic and Biomolecular Chemistry
Additional Information:
This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1600/1606
Subjects:
ID Code:
68711
Deposited By:
Deposited On:
25 Feb 2014 09:58
Refereed?:
Yes
Published?:
Published
Last Modified:
06 Aug 2020 02:22