title: Structure of the trehalose-6-phosphate phosphatase from Brugia malayi reveals key design principles for anthelmintic drugs.
abstract: Parasitic nematodes are responsible for devastating illnesses that plague many of the world's poorest populations indigenous to the tropical areas of developing nations. Among these diseases is lymphatic filariasis, a major cause of permanent and long-term disability. Proteins essential to nematodes that do not have mammalian counterparts represent targets for therapeutic inhibitor discovery. One promising target is trehalose-6-phosphate phosphatase (T6PP) from Brugia malayi. In the model nematode Caenorhabditis elegans, T6PP is essential for survival due to the toxic effect(s) of the accumulation of trehalose 6-phosphate. T6PP has also been shown to be essential in Mycobacterium tuberculosis. We determined the X-ray crystal structure of T6PP from B. malayi. The protein structure revealed a stabilizing N-terminal MIT-like domain and a catalytic C-terminal C2B-type HAD phosphatase fold. Structure-guided mutagenesis, combined with kinetic analyses using a designed competitive inhibitor, trehalose 6-sulfate, identified five residues important for binding and catalysis. This structure-function analysis along with computational mapping provided the basis for the proposed model of the T6PP-trehalose 6-phosphate complex. The model indicates a substrate-binding mode wherein shape complementarity and van der Waals interactions drive recognition. The mode of binding is in sharp contrast to the homolog sucrose-6-phosphate phosphatase where extensive hydrogen-bond interactions are made to the substrate. Together these results suggest that high-affinity inhibitors will be bi-dentate, taking advantage of substrate-like binding to the phosphoryl-binding pocket while simultaneously utilizing non-native binding to the trehalose pocket. The conservation of the key residues that enforce the shape of the substrate pocket in T6PP enzymes suggest that development of broad-range anthelmintic and antibacterial therapeutics employing this platform may be possible.
authors.affiliation: Department of Chemistry, Boston University, Boston, Massachusetts, United States of America.
authors.forename: Jeremiah D
authors.initials: JD
authors.lastname: Farelli
authors.affiliation: New England Biolabs, Division of Parasitology, Ipswich, Massachusetts, United States of America.
authors.forename: Brendan D
authors.initials: BD
authors.lastname: Galvin
authors.affiliation: New England Biolabs, Division of Parasitology, Ipswich, Massachusetts, United States of America.
authors.forename: Zhiru
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico, United States of America.
authors.forename: Chunliang
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Chemistry, Boston University, Boston, Massachusetts, United States of America.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Aono
authors.affiliation: Department of Chemistry, Boston University, Boston, Massachusetts, United States of America.
authors.forename: Megan
authors.initials: M
authors.lastname: Garland
authors.affiliation: Department of Chemistry, Boston University, Boston, Massachusetts, United States of America.
authors.forename: Olivia E
authors.initials: OE
authors.lastname: Hallett
authors.affiliation: New England Biolabs, Division of Parasitology, Ipswich, Massachusetts, United States of America.
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Causey
authors.affiliation: New England Biolabs, Division of Parasitology, Ipswich, Massachusetts, United States of America.
authors.forename: Alana
authors.initials: A
authors.lastname: Ali-Reynolds
authors.affiliation: Department of Chemistry, Boston University, Boston, Massachusetts, United States of America.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Saltzberg
authors.affiliation: New England Biolabs, Division of Parasitology, Ipswich, Massachusetts, United States of America.
authors.forename: Clotilde K S
authors.initials: CK
authors.lastname: Carlow
authors.affiliation: Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico, United States of America.
authors.forename: Debra
authors.initials: D
authors.lastname: Dunaway-Mariano
authors.affiliation: Department of Chemistry, Boston University, Boston, Massachusetts, United States of America.
authors.forename: Karen N
authors.initials: KN
authors.lastname: Allen
mesh_terms: D000818:Animals; D000871:Anthelmintics; D017178:Brugia malayi / Q000201:enzymology*; D015195:Drug Design; D005368:Filariasis / Q000188:drug therapy / Q000201:enzymology; D015801:Helminth Proteins / Q000737:chemistry*; D008958:Models, Molecular; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry*; D017434:Protein Structure, Tertiary
chemical_list: D000871:Anthelmintics; D015801:Helminth Proteins; C023178:trehalose-phosphatase; D010744:Phosphoric Monoester Hydrolases