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 language | English (US) |
|---|---|
| Pages (from-to) | 301-308 |
| Number of pages | 8 |
| Journal | Journal of Medical Entomology |
| Volume | 43 |
| Issue number | 2 |
| DOIs | |
| State | Published - 2006 |
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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 journal › Article
}
TY - JOUR
T1 - Glossina proteolytic lectin does not require a carbohydrate moiety for enzymatic or trypanosome-transforming activities
AU - Amin, Daniel N.
AU - Kamita, Shizuo G.
AU - Muluvi, Geoffrey M.
AU - Machuka, Jesse
AU - Hammock, Bruce D.
AU - Osir, Ellie O.
PY - 2006
Y1 - 2006
N2 - 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.
AB - 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.
KW - Glossina
KW - Proteolytic lectin
KW - Trypanosome
KW - Tsetse fly
UR - http://www.scopus.com/inward/record.url?scp=33751001642&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33751001642&partnerID=8YFLogxK
U2 - 10.1603/0022-2585(2006)043[0301:GPLDNR]2.0.CO;2
DO - 10.1603/0022-2585(2006)043[0301:GPLDNR]2.0.CO;2
M3 - Article
C2 - 16619615
AN - SCOPUS:33751001642
VL - 43
SP - 301
EP - 308
JO - Journal of Medical Entomology
JF - Journal of Medical Entomology
SN - 0022-2585
IS - 2
ER -