Tyrosine sufafon is a posttranslational mocffcation involved in the processing of secretory proteins. Presence of Tyrosylprotein sutotansferase (TPST) activity in submandfcUar salivary glands was reported earier. In tris report we demonstrate the presence of TPST activity in human saliva. Human saliva was cdected, centrifugea at 10, 000 x g for 30 min. and the dear supernatant was used for TPST analysis. The TPST activity in 10, 000 x g supernatant was 12 pmoleAng/30min. (n = 10). The enzyme displayed a pH optimum of 6.8 and dkl not reqtire the presence of Triton X-100, NaF or 5'-AMP for its activity as observed for the salivary gland enzyme. Mn2+, Ca2+ and partially Mg2+ stimulated (he TPST activity whereas other metal ions Zn2+, Cu2+, Ba2+ had no effect Addrfon of various concentrators (0-120mM) cf etfianol had no effect on (he enzyme activity. The enzyme was purifed by imnunoaffinity column using potydonal ant-TPST antibody. Affinity purifed salivary TPST showed a single band of 50-54 kDa by SDS-PAGE. Presence cf TPST was also noticed in human parotid saliva It is suggested that the TPST of human saBva may play an important rote in the regulation of the biological activities of trie proteins present in the saliva .
|Original language||English (US)|
|State||Published - Dec 1 1998|
All Science Journal Classification (ASJC) codes
- Molecular Biology