Vitellogenin of the tobacco hornworm, Manduca sexta: properties and endocytotic incorporation into follicles

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6701214

Osir, E O

Manduca sexta vitellogenin is a phosphoglycolipoprotein (M/sub r/ approx. 500,000) that contains two copies of the apoproteins 13% lipids, 3% carbohydrates and 0.6% phosphorus. The two apoproteins are immunologically distinct and apovitellogenin-II is not completely accessible to the aqueous environment in the intact molecule. The carbohydrate moiety located on apovitellogenin-I has a high mannose structure. Follicle membranes bind /sup 125/I-labeled vitellogenin with high affinity and specificity. Total binding sites were estimated at 4 x 10/sup 14/ sites/g of follicle membrane protein. The binding was sensitive to pH and calcium. Competition studies showed that binding of vitellogenin was blocked by vitellin and deglycosylated vitellogenin but not by lipophorin, microvitellogenin or apovitellogenin-II. These results suggest that the uptake of vitellogenin involves binding to specific receptors on follicle membranes and the carbohydrate moiety and apovitellogenin-II are not involved in the interaction with the receptors.

• Research Organization: Arizona Univ., Tucson (USA)
• OSTI ID: 6701214
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
ANNELIDS
APOLIPOPROTEINS
BETA DECAY RADIOISOTOPES
CALCIUM COMPOUNDS
CARBOHYDRATES
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL PROPERTIES
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
GLUCOPROTEINS
INTERMEDIATE MASS NUCLEI
INVERTEBRATES
IODINE 125
IODINE ISOTOPES
ISOTOPES
LIPIDS
LIPOPROTEINS
MEMBRANE PROTEINS
MEMBRANES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PH VALUE
PROTEINS
RADIOASSAY
RADIOISOTOPES
RECEPTORS
SACCHARIDES