Immunodissection of yolk lipovitellin (LV1) demonstrates the existence of different LV1-domains and suggests a complex family of vitellogenin genes in the lizard Anolis pulchellus

In the tropical lizard Anolis pulchellus vitellogenin,(Vtg), the plasma precursor of egg-yolk proteins, consists of a family of five polypeptides ranging between 116 and 226 kDa. In addition, lipovitellin-LV1, the main yolk protein, resolves electrophoretically into several forms. This suggests that yolk LV1 is a mixture of similar but distinct peptides that presumably correspond to the LV1 domains of the plasma Vtgs. Here, we test the hypothesis that each component of yolk LV1 is distinct enough to be antigenically different and that these components correspond to cleavage products of plasma Vtg polypeptides. Our experimental approach is based on adsorptions of a polyclonal antiserum against purified LV1 with membrane-immobilized Vtgs. This immunochemical design permitted us to dissect sub-populations of LV1 antibodies that specifically reacted with one of the plasma Vtgs. The presence of unique epitopes in the LV1 components directly indicates differences among the structures of their plasma Vtg precursors and supports the idea of a heterogeneous multigene Vtg family in Anolis. These results also show the potential of this immunoadsorption approach for the identification, and even separation of proteins sharing a high degree of similarity in their molecular structures. (C) 2002 Elsevier Science Inc. All rights reserved.