Premium
Studies on vitellogenin from the tobacco hornworm, Manduca sexta
Author(s) -
Osir Ellie O.,
Wells Michael A.,
Law John H.
Publication year - 1986
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.940030302
Subject(s) - manduca sexta , vitellogenin , biology , biochemistry , ouchterlony double immunodiffusion , in vivo , chromatography , microbiology and biotechnology , antiserum , antibody , chemistry , botany , immunology , gene , larva
In the tobacco hornworm moth, Manduca sexta , vitellogenin (Vg) is a very high‐density (1.29 g/ml) phosphoglycolipoprotein containing 13% lipids, 3% carbohydrates, and 0.6% protein‐bound phosphorus. Vitellogenin (M r ∼500,000) has two apoproteins designated apoVg‐l (M r 177,000 ± 3,600) and apoVg‐ll (M r 45,000 ± 5,000). ApoVg‐l and apoVg‐II can be dissociated with 6 M guanidine HCI and separated from each other by gel permeation chromatography. Immunoblotting experiments using antibodies against the apoproteins showed that apoVg‐l and apoVg‐II antigens were immunologically distinct polypeptides. Antibodies against Vg reacted only with apoVg‐l. Antibodies against Vg and apoVg‐l reacted with Vg in double immunodiffusion experiments, whereas antibodies against apoVg‐II did not. These results suggest that in the native Vg molecule, apoVg‐II is positioned inside the molecule away from the aqueous environment. Only apoVg‐I contained covalently bound carbohydrate as shown by fluorescein isothiocyanateconjugated concanavalin A, periodate‐Schiff reagent, and in vivo labeling with 3 H‐Man. In vivo labeling with 32 P‐inorganic phosphate and chemical determination showed that apoproteins of both Vg and vitellin contain covalently bound phosphate groups.