Biochemical and cellular characterization of lipophorin-midgut interaction in the hematophagous Panstrongylus megistus (Hemiptera: Reduviidae).

FRUTTERO L; RUBIOLO ER; CANAVOSO LE

INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY

Elsevier Science-Elsevier Ltd

Lugar: Amsterdam; Año: 2009 vol. 39 p. 322 - 322

0965-1748

n order to better understand the metabolism of dietary lipids in hematophagous insects, we have performed a biochemical and cellular characterization of lipophorin (Lp)?midgut interaction in Panstrongylus megistus, a vector of Chagas? disease. The study was accomplished by solid-phase binding assays or with iodinated Lp (125I-Lp), using midgut membranes from fifth instar nymphs after ecdysis and after insects received a blood meal. Results obtained from both physiological conditions indicated that Lp interacted specifically with the midgut, implying the participation of receptors. Binding capacity of lipophorin to membranes was dependent on the amount of membranes added in the system, reaching saturation at 0.1 mg/ml. However, membranes obtained after a blood meal exhibited higher binding activity. Saturation kinetics results using 125I-Lp suggested a single binding site with high affinity for Lp in the midgut membranes (Kd ¼ 5.1 3.6 108 M). The unrelated lipoprotein, human