Mucin 1 (MUC1) peptide fused with Q11 (MUC1-Q11) having 35 residues has previously been shown to form amyloid fibrils. Using time-dependent and high-resolution atomic force microscopy (AFM) imaging, it is revealed that the formation of individual MUC1-Q11 fibrils entails nucleation and extension at both ends. This process can be altered by local mechanical perturbations using AFM probes.
View Article and Find Full Text PDFOligo(ethylene glycol)-linked light fluorous tags have been found to be optimal for conjugating to glycans for both high-yield enzymatic glycosylation reactions using one-pot multienzyme (OPME) systems and quick product purification using fluorous solid-phase extraction (FSPE) cartridges. The combination of OPME glycosylation systems and the FSPE cartridge purification scheme provides a highly effective strategy for facile synthesis and purification of glycans.
View Article and Find Full Text PDFA series of STn-MUC1 and ST-MUC1 glycopeptides containing naturally occurring and non-natural sialic acids have been chemoenzymatically synthesized from Tn-MUC1 glycopeptide using one-pot multienzyme (OPME) approaches. In situ generation of the sialyltransferase donor cytidine 5'-monophosphate-sialic acid (CMP-Sia) using a CMP-sialic acid synthetase in the presence of an extra amount of cytidine 5'-triphosphate (CTP) and removal of CMP from the reaction mixture by flash C18 cartridge purification allow the complete consumption of Tn-MUC1 glycopeptide for quantitative synthesis of STn-MUC1. A Campylobacter jejuni β1-3GalT (CjCgtBΔ30-His6) mutant has been found to catalyze the transfer of one or more galactose residues to Tn-MUC1 for the synthesis of T-MUC1 and galactosylated T-MUC1.
View Article and Find Full Text PDFA promiscuous UDP-sugar pyrophosphorylase (BLUSP) was cloned from Bifidobacterium longum strain ATCC55813 and used efficiently with a Pasteurella multocida inorganic pyrophosphatase (PmPpA) with or without a monosaccharide 1-kinase for one-pot multienzyme synthesis of UDP-galactose, UDP-glucose, UDP-mannose, and their derivatives. Further chemical diversification of a UDP-mannose derivative resulted in the formation of UDP-N-acetylmannosamine.
View Article and Find Full Text PDFThe synthesis of glycosylated Fmoc amino acids by reaction of mono- and disaccharide peracetates with Fmoc amino acids having free carboxyl groups was rapidly promoted by Lewis acids (SnCl(4), BF(3)·Et(2)O) under microwave irradiation. The products are useful building blocks for the synthesis of glycopeptides.
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