Glossina proteolytic lectin does not require a carbohydrate moiety for enzymatic or trypanosome-transforming activities

Daniel N. Amin, Shizuo G. Kamita, Geoffrey M. Muluvi, Jesse Machuka, Bruce D. Hammock, Ellie O. Osir

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The developmental cycle of the cyclically transmitted African trypanosome involves an obligatory passage through the tsetse fly, Glossina spp. This intricate relationship requires the presence of molecules within the insect vector, including a midgut lectin, that interact with the trypanosome. Recently, a gene encoding for a proteolytic lectin, with trypanosome-transforming activity, was isolated from a midgut cDNA library of Glossina fuscipes fuscipes Austen in our laboratory. Using the same approach, we have identified a similar gene from a midgut cDNA library of Glossina austeni (Newstead). The protein encoded by this gene was expressed in bacteria and a baculovirus-based expression system. The baculovirus-expressed lectin was found in the medium of baculovirus-infected Sf-21 cell cultures, indicating that the tsetse fly-derived signal peptide was recognized and cleaved by the Sf-21 cells. The baculovirus-expressed protein also was glycosylated despite the absence of classical O-linked and N-linked sugar attachment motifs. Both the baculovirus- and bacterium-expressed lectin proteins were shown to agglutinate trypanosomes and rabbit red blood cells in vitro. This agglutination was strongly inhibited by D-glucosamine. D-Glucosamine also inhibited the action of the authentic and recombinant lectins upon the chromogenic substrate Chromozym TRY. Interestingly, both baculovirus- and bacterium-expressed lectins showed no significant differences in terms of these activities, indicating that a sugar moiety is not essential for biological activity. Our results provide an important molecular tool for further characterization of Glossina proteolytic lectin.

Original languageEnglish (US)
Pages (from-to)301-308
Number of pages8
JournalJournal of Medical Entomology
Volume43
Issue number2
DOIs
StatePublished - 2006

Fingerprint

Tsetse Flies
Trypanosomiasis
Glossina
Baculoviridae
Lectins
lectins
Carbohydrates
carbohydrates
midgut
glucosamine
Glucosamine
Bacteria
Gene Library
cDNA libraries
bacteria
Glossina fuscipes fuscipes
Glossina austeni
Insect Vectors
sugars
Chromogenic Compounds

Keywords

  • Glossina
  • Proteolytic lectin
  • Trypanosome
  • Tsetse fly

ASJC Scopus subject areas

  • Insect Science
  • veterinary(all)

Cite this

Glossina proteolytic lectin does not require a carbohydrate moiety for enzymatic or trypanosome-transforming activities. / Amin, Daniel N.; Kamita, Shizuo G.; Muluvi, Geoffrey M.; Machuka, Jesse; Hammock, Bruce D.; Osir, Ellie O.

In: Journal of Medical Entomology, Vol. 43, No. 2, 2006, p. 301-308.

Research output: Contribution to journalArticle

Amin, Daniel N. ; Kamita, Shizuo G. ; Muluvi, Geoffrey M. ; Machuka, Jesse ; Hammock, Bruce D. ; Osir, Ellie O. / Glossina proteolytic lectin does not require a carbohydrate moiety for enzymatic or trypanosome-transforming activities. In: Journal of Medical Entomology. 2006 ; Vol. 43, No. 2. pp. 301-308.
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