A novel Ser O-glucuronidation in acidic proline-rich proteins identified by tandem mass spectrometry.
Human acidic proline-rich salivary protein PRP-1 and its C-terminally truncated form PRP-3 were analyzed by electrospray tandem mass spectrometry. Post-translational modifications were detected and characterized. A pyroglutamic acid residue was demonstrated at the N-terminus, Ser-8 and Ser-22 were shown to be phosphorylated and an O-linked glucuronic acid conjugation was identified. The latter modification was located to Ser-17 and found to be present in approximately 40% of the polypeptides.
Jonsson
A P
AP
Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
Griffiths
W J
WJ
Bratt
P
P
Johansson
I
I
Strömberg
N
N
Jörnvall
H
H
Bergman
T
T
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D020723:Glucuronic Acid / Q000378:metabolism*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D011392:Proline / Q000737:chemistry; D055232:Proline-Rich Protein Domains; D011499:Protein Processing, Post-Translational; D012694:Serine / Q000378:metabolism*; D013997:Time Factors; D014357:Trypsin / Q000378:metabolism
D010455:Peptides; D012694:Serine; D020723:Glucuronic Acid; D011392:Proline; D014357:Trypsin