Effect of serine O-glycosylation on cis-trans proline isomerization.
In order to examine the ability of an O-glycosylated serine residue preceding proline to stabilize a cis amide conformation in a fashion similar to that observed with aromatic amino acid residues, we prepared a series of glycosylated analogs of a small linear peptide which we have previous reported to contain a cis conformation of an amide bond between tyrosine and proline. The glycopeptides were prepared by incorporating glycosylated N alpha- (fluoren-9-yl) methoxycarbonyl (Fmoc) amino acids into a standard solid phase peptide synthesis protocol. The peptides and glycopeptides were analyzed using 2-dimensional NMR spectroscopy. Unlike the case where the residue preceding proline was tyrosine, no signals corresponding to a cis proline conformation were detected in the spectra of the two glycopeptides containing serine O-glycosylated with either beta-linked N-acetyl glucosamine or alpha-linked N-acetyl galactosamine in the position preceding proline.
Pao
Y L
YL
Department of Biochemistry, Oxford Glycobiology Institute, Oxford University, United Kingdom.
Wormarld
M R
MR
Dwek
R A
RA
Lellouch
A C
AC
D000117:Acetylglucosamine; D000595:Amino Acid Sequence; D006020:Glycopeptides / Q000737:chemistry*; D006031:Glycosylation; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry*; D011392:Proline; D011487:Protein Conformation; D012694:Serine; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014443:Tyrosine
D006020:Glycopeptides; D009842:Oligopeptides; D014443:Tyrosine; D012694:Serine; D011392:Proline; D000117:Acetylglucosamine