Golgi tyrosine residues

The tyrosine protein sulfotransferase preparations from Golgi-enriched membranes have been used for sulfation of synthetic mono- and multiple-tyrosine peptides related to known sulfation sites in proteins and peptides at analytical levels to establish the enzyme specificities.1f11-13] Preparative sulfations have not been carried out to date. A novel type of arylsulfotransferase produced by Eubacterium A-44 which is part of the human intestinal flora, has recently been discovered.1"1911111 This enzyme catalyzes the transfer of a sulfate group from phenolic sulfate, but not from 3 -phosphadenosine-5 -phosphasulfate, to other phenolic compounds. Using 4-nitrophenylsulfate as a donor substrate and tyrosine-containing peptides and proteins as acceptor substrates it catalyzes the specific sulfation of the tyrosine residues.11111-112 While this enzyme very efficiently sulfates tyrosine derivatives, the... 

With up to 1% of eukaryotic proteins potentially containing sulfotyrosine residues, sulfation of tyrosines is a common posttranslational modification whose biological impact has only just started to be elucidated (Ludeman Stone, 2014 Moore, 2003 Seibert et al., 2008). In humans and most mammals, there are two isoforms of the enzyme responsible for tyrosine sulfation these enzymes are tyrosylprotein sulfotransferase 1 and 2 (TPST-1 and TPST-2) (Moore, 2003 Seibert Sakmar, 2008). TPST-1 and TPST-2 are located in the irans-Golgi network and this limits tyrosine sulfation to secreted or membrane proteins (Moore, 2003 Seibert Sakmar, 2008). Both enzymes utilize the cosubstrate PAPS, or 3Gphosphoadenosine-5 -phosphosulfate, as the sulfate donor to catalyze the sulfation of a tyrosine s phenolic hydroxyl in a substrate protein or peptide as seen in Fig. 1 (Moore, 2003 Seibert Sakmar, 2008). 

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