Purification and properties of an 18-kilodalton, 1,25-dihydroxyvitamin D3 modulated protein from embryonic chick intestine.
An 18,000-dalton protein (pI = 5.1) shown previously to be modulated by 1,25-dihydroxyvitamin D3 was purified to allow its further characterization. This protein from embryonic chick intestine was shown to comigrate during two-dimensional electrophoresis with an abundant protein from the intestine of 4-week-old chickens. The protein was purified from 4-week chick intestine and analyzed for amino acid composition, and 28 amino acids of its N-terminal sequence were determined. The N-terminal amino acid sequence had significant homology to cellular retinol binding protein II, an intestinal protein that has been recently sequenced. The purified 18-kilodalton protein was shown to bind retinol by fluorescence spectrophotometry. This 18-kilodalton protein is dramatically changed by 1,25-dihydroxyvitamin D3 in the chick embryonic organ culture system. Therefore, further study of it may lead to a better understanding of vitamin A and D interaction and how 1,25-dihydroxyvitamin D3 acts through proteins to stimulate intestinal calcium and phosphate transport.
Finlay
J A
JA
Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin--Madison 53706.
DeLuca
H F
HF
D000595:Amino Acid Sequence; D000818:Animals; D002117:Calcitriol / Q000494:pharmacology*; D002642:Chick Embryo; D002645:Chickens; D003600:Cytosol / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000196:embryology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011506:Proteins / Q000302:isolation & purification* / Q000378:metabolism
D011506:Proteins; D002117:Calcitriol