Purification and characterization of spider vitellins from the eggs of Polybetes pythagoricus

LAINO A,; GARCÍA, F.; CUNNINGHAM, M.; HERAS, H.

SM Tucuman

Congreso; XLV Reunión SAIByBM; 2009

XLV Reunión SAIByBM

Vitellins are essential ovigerous species for embryogenesis and viability of progeny, but there virtually no information in arachnids. The present work aims to purify and characterize the vitellins from P. pythagoricus spiders. Lipoproteins were isolated by ultracentrifugation and their lipids, proteins and carbohydrates moieties analyzed by a combination of chromatography, electrophoresis and immunology. Two vitellins of high and very high density, with 36.0 and 15.6 % total lipids, respectively were isolated, the HDL named lipovitellin1 (LV1) and the VHDL, LV2. Phospholipids were the major components in both, representing 90.7 and 45.5% of total lipids, respectively. Major fatty acids were 18:1>18:2>16:0>18:0 in LV1, and 16:0>18:1>18:2>18:0 in LV2. Native LV1 has a MW of 680 KDa, and 2 apolipoproteins of 74 and 25 kDa. Both LVs are glycosylated with 1.48 and 0.69 % by wt total carbohydrates, in LV1 and LV2, respectively. Native LV2 is more heterogeneous with 3 particles of MW 571, 400 and 270 kDa. The 3 have the same apolipoproteín composition with 3 subunits of 181, 93 and 60 KDa, though in different ratios. Espectrophotometric and Western blot analysis discarded the presence of the respiratory pigment hemocyanin in both, an important component in adult spiders circulating lipoproteins. LV1 and LV2 are the first egg lipoproteins described in Arachnids other than mites.