Identification and characterization of the hemoglobin-binding domain of hemoglobin receptor in Leishmania

FEBS Lett. 2021 Feb;595(4):548-558. doi: 10.1002/1873-3468.14027. Epub 2021 Jan 2.

Abstract

Leishmania internalize hemoglobin (Hb) via a specific receptor (HbR) for their survival. To identify the Hb-binding domain of HbR, we cloned and expressed several truncated proteins of HbR and determined their ability to bind Hb. Our findings reveal that 90% of Hb-binding activity is retained in HbR41-80 in comparison with HbR1-471 . We synthesized a 40 amino acid peptide (SSEKMKQLTMYMIHEMVEGLEGRPSTVRMLPSFVYTSDPA) corresponding to HbR41-80 and found that it specifically binds Hb. Subsequently, we found that the HbR41-80 peptide completely blocks Hb uptake in both promastigote and amastigote forms of Leishmania and, thereby, inhibits the growth of the parasite. These results demonstrate that HbR41-80 is the Hb-binding domain of HbR, which might be used as a potential therapeutic agent to inhibit the growth of Leishmania.

Keywords: Leishmania; domain; endocytosis; hemoglobin; receptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antiprotozoal Agents / chemical synthesis
  • Antiprotozoal Agents / metabolism*
  • Antiprotozoal Agents / pharmacology
  • Binding, Competitive
  • Cloning, Molecular
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Gene Expression
  • Genetic Vectors / chemistry
  • Genetic Vectors / metabolism
  • Hemoglobins / chemistry*
  • Hemoglobins / metabolism
  • Leishmania donovani / drug effects
  • Leishmania donovani / genetics
  • Leishmania donovani / growth & development
  • Leishmania donovani / metabolism*
  • Life Cycle Stages / drug effects
  • Life Cycle Stages / genetics*
  • Models, Molecular
  • Peptides / chemical synthesis
  • Peptides / metabolism*
  • Peptides / pharmacology
  • Protein Binding
  • Protein Conformation, alpha-Helical
  • Protein Conformation, beta-Strand
  • Protein Interaction Domains and Motifs
  • Protozoan Proteins / chemistry*
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism
  • Receptors, Cell Surface / chemistry*
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Structural Homology, Protein

Substances

  • Antiprotozoal Agents
  • Hemoglobins
  • Peptides
  • Protozoan Proteins
  • Receptors, Cell Surface
  • Recombinant Proteins