ISSN:
0739-4462
Keywords:
Manduca sexta vitellogenin
;
apoproteins
;
immunology
;
Chemistry
;
Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
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 (Mr∼500,000) has two apoproteins designated apoVg-l (Mr 177,000 ± 3,600) and apoVg-ll (Mr45,000 ± 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 3H-Man. In vivo labeling with 32P-inorganic phosphate and chemical determination showed that apoproteins of both Vg and vitellin contain covalently bound phosphate groups.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/arch.940030302
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