(2017) One-pot ligation-oxidative deselenization at selenocysteine and selenocystine. 23 (4 A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription.For more information, please contact eprints@nottingham.ac.uk FULL PAPEROne-Pot Ligation-Oxidative Deselenization at Selenocysteine and Selenocystine.Lara R. Malins, [a] Siyao Wang [a] and Richard J. Payne [a] * Abstract: The use of native chemical ligation at selenocysteine (Sec) with peptide thioesters and additive-free selenocystineselenoester ligation in concert with one-pot oxidative deselenization chemistry is described. These approaches provide a simple and rapid method for accessing native peptides with serine in place of Sec at the ligation junction. The efficiency of both variants of the one-pot ligation-oxidative deselenization chemistry is probed through the synthesis of a MUC5AC-derived glycopeptide.

We describe the synthesis and incorporation of α- and β-configured rhamnosyl arginine cassettes into Pseudomonas aeruginosa elongation factor P-derived glycopeptides. These were used to unequivocally determine the native anomeric configuration of the rhamnose moiety in EF-P.

Semisynthesis and characterization of homogeneously mono- and di-PEGylated full length PrP variants to study the impact of PEGylation (as N-glycan mimics) on protein folding and aggregation.

Chemokines are secreted proteins that regulate leukocyte migration during inflammatory responses by signaling through chemokine receptors. Full length CC chemokine ligand 14, CCL14(1–74), is a weak agonist for the chemokine receptor CCR1, but its activity is substantially enhanced upon proteolytic cleavage to CCL14(9–74). CCL14 is O-glycosylated at Ser7, adjacent to the site of proteolytic activation. To determine whether glycosylation regulates the activity of CCL14, we used native chemical ligation to prepare four homogeneously glycosylated variants of CCL14(1–74). Each protein was assembled from three synthetic peptide fragments in “one-pot” using two sequential ligation reactions. We show that while glycosylation of CCL14(1–74) did not affect CCR1 binding affinity or potency of activation, sialylated variants of CCL14(1–74) exhibited reduced activity after treatment with plasmin compared to nonsialylated forms. These data indicate that glycosylation may influence the biological activity of CCL14 by regulating its conversion from the full-length to the truncated, activated form.

Herein we describe the synthesis of glycopeptide fragments from the death domains of TRADD and FADD bearing the recently discovered Nω-GlcNAc-β-arginine post-translational modification. TRADD and FADD glycopeptides were accessed through the use of a suitably protected synthetic glycosylamino acid 'cassette' that could be directly incorporated into conventional solid phase peptide synthesis (SPPS) protocols.