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Human cationic trypsinogen is sulfated on Tyr154
Author(s) -
SahinTóth Miklós,
Kukor Zoltán,
Nemoda Zsófia
Publication year - 2006
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2006.05501.x
Subject(s) - trypsinogen , cationic polymerization , sulfation , chemistry , biochemistry , trypsin , enzyme , organic chemistry
The crystal structure of human pancreatic cationic trypsin showed the chemical modification of Tyr154, which was originally described as phosphorylation [Gaboriaud C, Serre L, Guy‐Crotte O, Forest E & Fontecilla‐Camps JC (1996) J Mol Biol 259 , 995–1010]. Here we report that Tyr154 is sulfated, not phosphorylated. Cationic and anionic trypsinogens were purified from human pancreatic juice and subjected to alkaline hydrolysis. Modified tyrosine amino acids were separated on a Dowex cation‐exchange column and analyzed by thin layer chromatography. Both human cationic and anionic trypsinogens contained tyrosine sulfate, but no tyrosine phosphate, whereas bovine trypsinogen contained neither. Furthermore, incorporation of [ 35 S]SO 4 into human cationic trypsinogen transiently expressed by human embryonic kidney 239T cells was demonstrated. Mutation of Tyr154 to Phe abolished radioactive sulfate incorporation, confirming that Tyr154 is the site of sulfation in cationic trypsinogen. Sulfated pancreatic cationic trypsinogen exhibited faster autoactivation than a nonsulfated recombinant form, suggesting that tyrosine sulfation of trypsinogens might enhance intestinal digestive zymogen activation in humans. Finally, sequence alignment revealed that the sulfation motif is only conserved in primate trypsinogens, suggesting that typsinogen sulfation is absent in other vertebrates.