Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-23T00:42:05.007Z Has data issue: false hasContentIssue false

Onchocerca retinol- and ivermectin-binding protein activity

Published online by Cambridge University Press:  26 March 2010

P. G. Lal
Affiliation:
Department of Ophthalmology, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425, USA
E. R. James
Affiliation:
Department of Ophthalmology, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425, USA

Summary

The presence of retinol-binding protein (RBP) activity in Onchocerca cervicalis adult worms and interaction with ivermectin has been studied using high pressure size exclusion chromatography (HPSEC). Four distinct peaks of [3H]-retinol incorporation were obtained corresponding to approximate molecular weights of 150, 67, 19·7 and 4–6 kDa, the 2 smaller Mr peaks accounting for most of the binding activity. Competition for binding using non-labelled retinol at 200-fold molar excess indicated that specific binding of retinol occurred only to the 19–7 kDa fraction. Competition by ivermectin also inhibited binding of [3H]-retinol to the third peak. Following incubation with [3H]-ivermectin & peaks of similar molecular weights were also detected by HPSEC in soluble adult worm homogenate, However, in this case the 150 kDa fraction was most prominent. Both non-labelled ivermectin and non-labelled retinol at 200-fold molar excess reduced binding of [3H]-ivermectin to all & fractions. These data indicate that the putative Onchocerca RBP has an approximate molecular weight of 19·7 kDa, that retinol also binds to 3 additional fractions non-specifically, that the pattern of binding of ivermectin to adult worm material is quantitatively and qualitatively different from the binding exhibited by retinol, and that ivermectin interferes with the binding of retinol to the 19·7 kDa Onchocerca protein.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bradford, M. M. (1976). A rapid and sensitive method for the quantification of microgram quantities of protein utilizing the principle of protein-dye binding. Analytical Biochemistry 72, 248–54.CrossRefGoogle Scholar
James, E. R. & Lal, P. G. (1994). Cross-reactivity between a 60 kDa protein from Onchocerca volvulus and interphotoreceptor retinoid binding protein. Investigative Ophthalmology and Visual Science 35, 1562.Google Scholar
Mahalanabis, D., Jalan, K. N., Maitra, T. K. & Agarwal, S. R. (1976). Vitamin A absorption in ascariasis. American Journal of Clinical Nutrition 29, 1372–5.CrossRefGoogle ScholarPubMed
Mustafa, K. Y., Turumen, U. & Gumaa, K. A. (1979). Serum vitamin A levels of patients with onchocerciasis from two areas of Sudan. Journal of Tropical Medicine and Hygiene 82, 122–7.Google ScholarPubMed
Ross, A. C. (1993a). Cellular metabolism and activation of retinoids: roles of cellular retinoid-binding proteins. FASEB Journal 7, 317–27.Google ScholarPubMed
Ross, A. C. (1993b). Overview of retinoid metabolism. Journal of Nutrition 123, 346–50.CrossRefGoogle ScholarPubMed
Sani, B. P. (1990). Parasite retinoid binding proteins. Methods in Enzymology 189, 348–56.CrossRefGoogle ScholarPubMed
Sani, B. P. & Comley, J. C. W. (1985). Role of retinoids and their binding proteins in filarial parasites and host tissues. Tropical Medicine and Parasitology 36 (Suppl.), 20–3.Google ScholarPubMed
Sani, B. P. & Vaid, A. (1988). Specific interaction of invermectin with retinol-binding protein from filarial parasites. The Biochemical Journal 249, 929–32.CrossRefGoogle Scholar
Sani, B. P., Vaid, A., Comley, J. C. W. & Montgomery, J. A. (1985). Novel retinoid-binding proteins from filarial parasites. The Biochemical Journal 232, 577–83.CrossRefGoogle ScholarPubMed
Storey, D. M. (1982). Vitamin A deficiency and the development of Litomosoides carinii in cotton rats. Zeitschrift fitr Parasitenkunde 67, 309–15.CrossRefGoogle ScholarPubMed
Sturchler, D., Wyss, F. & Hanck, A. (1981). Retinol, onchocerciasis and Onchocerca volvulus. Transactions of the Royal Society of Tropical Medicine and Hygiene 71, 617–25.CrossRefGoogle Scholar
Sturchler, D., Holzer, B., Hanck, A. & Degremont, A. (1983). The influence on the serum concentrations of retinol and retinol binding protein of a rural population in Liberia. Acta Tropica 40, 261–9.Google ScholarPubMed
Wolf, G. (1991). The intracellular vitamin A-binding proteins: and overview of their functions. Nutritional Review 49, 112.Google ScholarPubMed