PURIFICATION AND PARTIAL CHARACTERIZATION OF VITELLIN FROM THE BLACK-LEGGED TICK, IXODES-SCAPULARIS

Vitellin from the black-legged tick, Ixodes scapularis, was purified f rom eggs using gel filtration and ion exchange chromatography, The pur ified protein had a native molecular mass of 480 kDa, Under reducing c onditions (sodium dodecyl sulfate-polyacrylamide gel electrophoresis; SDS-PAGE), vitellin was composed of seven polypeptides each at 154, 13 5, 87, 78, 67, 64 and 35 kDa, The isoelectric point was pH 6.9 and abs orption maxima for the yolk protein were 280 and 400 nm, As in other t icks, vitellin from I, scapularis is also a hemoglycoli-poprotein, Car bohydrates detected in vitellin were predominantly mannose with a smal l amount of N-acetylglucosamine, Lipids detected by thin layer chromat ography (TLC) were triglycerides, free fatty acids, and cholesterol, P hospholipids associated with vitellin were phosphatidylethanolamine an d phosphatidylcholine, Polyclonal serum produced in rabbits recognized vitellin from the eggs and ovaries, and vitellogenin from the hemolym ph and fat body in reproductive females, This is the first report on t he characterization of yolk proteins from a prostriate tick, (C) 1997 Elsevier Science Ltd.