Study of lipid transport system in South American tarantula Grammostola rosea

CUNNINGHAM MONICA; LAINO ALDANA; SUAREZ GUSTAVO; LINO AGUSTINA; GARCIA FERNANDO

Pueto Varas

Congreso; XLIX Annual Meeting Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2013

Lipids due to its hydrophobic nature are transported in the hemolymph mainly by lipoproteic fractions. In the present work we studied the components of lipid transport of the spider Grammostola rosea. Through ultracentrifugation two lipoproteic fractions are isolated, one of high density named Gr-HDL (δ = 1.13-1.15 g/ml) and the other of very high density called Gr-VHDL (δ = 1.23-1.25 g/ml). Gr-VHDL in hemolymph is majority in relation to Gr-HDL. In this sense Gr-VHDL fraction has 98.6% of hemolymphatic proteins, transporting 89.3% of lipids circulating in hemolymph. Both lipoproteic fractions possess phospholipids such as majority lipids and 18:1, 16:0, 18:2 and 18:0 as the major fatty acids. Through in vitro assays with different 14C-lipid, it was observed that Gr-VHDL takes up mainly free fatty acids and triacylglycerols unlike that observed for Gr-HDL in relation to phosphatidylcholine. Through electrophoresis it was observed that Gr-VHDL has three apolipoproteins: a predominant band of 68 kDa and two others of 99 and 121 kDa. Gr-HDL displayed a predominant band of 93 kDa and other minoritary of 249 kDa. In conclusion, this study reports lipid and proteic characterization of the components of the lipid transport system in tarantula, using G.rosea as a model. The role of each protein in relation to lipid uptake is sustained by in vitro assays.  This work was supported by grants from: CONICET-PIP no. 075 and PICT no. 2010-1270, Argentina.