Molecular cloning, biochemical characterization, and partial protective immunity of the heme-binding glutathione S-transferases from the human hookworm Necator americanus

Infect Immun. 2010 Apr;78(4):1552-63. doi: 10.1128/IAI.00848-09. Epub 2010 Feb 9.


Hookworm glutathione S-transferases (GSTs) are critical for parasite blood feeding and survival and represent potential targets for vaccination. Three cDNAs, each encoding a full-length GST protein from the human hookworm Necator americanus (and designated Na-GST-1, Na-GST-2, and Na-GST-3, respectively) were isolated from cDNA based on their sequence similarity to Ac-GST-1, a GST from the dog hookworm Ancylostoma caninum. The open reading frames of the three N. americanus GSTs each contain 206 amino acids with 51% to 69% sequence identity between each other and Ac-GST-1. Sequence alignment with GSTs from other organisms shows that the three Na-GSTs belong to a nematode-specific nu-class GST family. All three Na-GSTs, when expressed in Pichia pastoris, exhibited low lipid peroxidase and glutathione-conjugating enzymatic activities but high heme-binding capacities, and they may be involved in the detoxification and/or transport of heme. In two separate vaccine trials, recombinant Na-GST-1 formulated with Alhydrogel elicited 32 and 39% reductions in adult hookworm burdens (P < 0.05) following N. americanus larval challenge relative to the results for a group immunized with Alhydrogel alone. In contrast, no protection was observed in vaccine trials with Na-GST-2 or Na-GST-3. On the basis of these and other preclinical data, Na-GST-1 is under possible consideration for further vaccine development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / administration & dosage
  • Aluminum Hydroxide / administration & dosage
  • Amino Acid Sequence
  • Animals
  • Antigens, Helminth / genetics
  • Antigens, Helminth / immunology*
  • Antigens, Helminth / metabolism*
  • Cloning, Molecular
  • Cricetinae
  • DNA, Complementary / genetics
  • DNA, Complementary / isolation & purification
  • DNA, Helminth / genetics
  • DNA, Helminth / isolation & purification
  • Gene Expression
  • Glutathione / metabolism
  • Glutathione Transferase / genetics
  • Glutathione Transferase / immunology*
  • Glutathione Transferase / metabolism*
  • Heme / metabolism*
  • Humans
  • Lipid Peroxidation
  • Molecular Sequence Data
  • Necator americanus / enzymology*
  • Necator americanus / genetics
  • Necator americanus / immunology*
  • Necatoriasis / immunology
  • Necatoriasis / prevention & control*
  • Open Reading Frames
  • Pichia / genetics
  • Recombinant Proteins / genetics
  • Recombinant Proteins / immunology
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Vaccines, Subunit / immunology


  • Adjuvants, Immunologic
  • Antigens, Helminth
  • DNA, Complementary
  • DNA, Helminth
  • Recombinant Proteins
  • Vaccines, Subunit
  • Heme
  • Aluminum Hydroxide
  • Glutathione Transferase
  • Glutathione