Purification and characterization of a midgut lectin-trypsin complex from the tsetse fly Glossina longipennis.
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Date
1995Author
Osir, E O
Abubakar, L
Imbuga, M O
Type
ArticleLanguage
enMetadata
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A blood-meal-induced lectin (agglutinin) with proteolytic activity was isolated from midgut extracts of Glossina longipennis by a two-step procedure involving anion-exchange chromatography. It is a glycoprotein [native molecular weight (M(r) 61,000 +/- 3000 da) composed of two noncovalently-linked subunits designated alpha (M(r), approximately 27,000 da) and beta (M(r), approximately 33,000 da). The trypsin activity and the glycosyl residues were present on the alpha- and beta-subunits, respectively. The native protein was capable of agglutinating both bloodstream-form and procyclic trypanosomes as well as rabbit red blood cells. This activity was strongly inhibited by D-glucosamine and weakly inhibited by N-acetyl-D-glucosamine. Similarly, soybean trypsin inhibitor abrogated agglutination of bloodstream-form parasites, whereas the procyclics were unaffected. The agglutination activity was sensitive to temperatures above 40 degrees C but was unaffected by chelators of metal ions. Antibodies raised against the protein were used in immunoblotting experiments to show the presence of a similar protein in several members of the Glossina species. However, no cross-reactivity was detected with midgut extracts prepared from sandflies, mosquitoes, or stable flies. It is proposed that this molecule might play an important role in differentiation of bloodstream-form trypanosomes into procyclic (midgut) forms.
URI
http://www.ncbi.nlm.nih.gov/pubmed/7624283http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/31024
Citation
Parasitol Res. 1995;81(4):276-81Publisher
University of Nairobi International Centre of Insect Physiology and Ecology, Nairobi, Kenya
Collections
- Faculty of Health Sciences (FHS) [10378]