Purification of proline-rich proteins from parotid glands of isoproterenol-treated rats.
Prolonged isoproterenol treatment of rats is known to cause hypertrophy and hyperplasia of the parotid glands. Our results show that a dramatic increase in the synthesis or accumulation in the parotid glands of a series of proteins rich in proline also occurs with isoproterenol treatment. After 10 days of treatment (5 mg of isoproterenol/day) these proline-rich proteins (PRPs) comprise more than 50% of the total soluble proteins in parotid gland homogenates. The PRPs are rapidly labeled in vivo by a single intraperitoneal injection of [3H]proline with maximum incorporation occurring at about 3. More than 90% of the [3h]proline found in parotid gland homogenates is incorporated into PRPs with less than 1% of the radioactivity in alpha-amylase. Tritium incorporated into PRPs was isolated as [3H]proline after acid hydrolysis. One acidic and six basic 3H-labeled PRPs were isolated from the 100,000 x g supernatant fraction of parotid gland homogenates by Sephadex G-100 and ion exchange chromatography. The six basic proteins accounted for about 90% of the total PRPs isolated.
D000818:Animals; D003600:Cytosol / Q000378:metabolism; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D010306:Parotid Gland / Q000187:drug effects / Q000378:metabolism*; D011392:Proline / Q000378:metabolism*; D014176:Protein Biosynthesis; D011506:Proteins / Q000302:isolation & purification; D051381:Rats
D011506:Proteins; D011392:Proline; D007545:Isoproterenol