C. Kasinathan et al., EFFECT OF PROSTAGLANDINS ON TYROSYLPROTEIN SULFOTRANSFERASE ACTIVITY RAT IN SUBMANDIBULAR SALIVARY-GLANDS, General pharmacology, 26(3), 1995, pp. 577-580
1. Tyrosylprotein sulfotransferase (TPST) is a key enzyme in the proce
ssing of several secretory proteins, including those found in saliva.
In this report, the effect of prostaglandins (PG) on TPST activity in
submandibular salivary gland was investigated. 2. The results revealed
that PGE(2) exhibited TPST stimulatory activity with a 1.5-fold stimu
lation at 100 mu M concentration and a half maximal stimulation at 50
mu M. The PGE(2) stimulation was accompanied by an increase in the aff
inity of TPST towards sulfate acceptor (Km 1.4 mu M-->0.12 mu M) with
little change in V-max. 3. The TPST activity was also stimulated by tw
o other major prostaglandins of salivary glands, PGF(2 alpha) and 6-Ke
to-PGF(1 alpha), however to lesser extent, 22 and 23%, respectively. A
rachidonic acid, an intermediate prostaglandin precursor, had no effec
t on TPST activity. 4. The results suggest that prostaglandins and in
particular PGE(2) may play a role in the regulation of TPST catalyzed
secretory protein tyrosine sulfation in salivary glands.