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Conformational choice and selectivity in singly and multiply hydrated monosaccharides in the gas phase.
Factors governing hydration, regioselectivity and conformational choice in hydrated carbohydrates have been examined by determining and reviewing the structures of a systematically varied set of singly and multiply hydrated monosaccharide complexes in the gas phase. This has been achieved through a co…
Site-selective glycosylation of proteins: creating synthetic glycoproteins.
In higher organisms, the functions of many proteins are modulated by post-translational modifications (PTMs). Glycosylation is by far the most diverse of the PTM processes. Natural protein production methods typically produce PTM or glycoform mixtures within which function is difficult to dissect or control. Che…
Functional and informatics analysis enables glycosyltransferase activity prediction.
The elucidation and prediction of how changes in a protein result in altered activities and selectivities remain a major challenge in chemistry. Two hurdles have prevented accurate family-wide models: obtaining (i) diverse datasets and (ii) suitable parameter frameworks that encapsulate activities in large sets.…
Lectin-directed enzyme activated prodrug therapy (LEAPT): Synthesis and evaluation of rhamnose-capped prodrugs.
The lectin-directed enzyme activated prodrug therapy (LEAPT) bipartite drug delivery system utilizes glycosylated enzyme, localized according to its sugar pattern, and capped prodrugs released by that enzyme. In this way, the sugar coat of a synthetic enzyme determines the site of release of a given drug. He…
Chemical mutagenesis: selective post-expression interconversion of protein amino acid residues.
The ability to alter protein structure by site-directed mutagenesis has revolutionized biochemical research. Controlled mutations at the DNA level, before protein translation, are now routine. These techniques allow specific, high fidelity interconversion largely between 20 natural, proteinogenic amino acids. N…
Palladium-mediated enzyme activation suggests multiphase initiation of glycogenesis.
Biosynthesis of glycogen, the essential glucose (and hence energy) storage molecule in humans, animals and fungi1, is initiated by the glycosyltransferase enzyme, glycogenin (GYG). Deficiencies in glycogen formation cause neurodegenerative and metabolic disease2-4, and mouse knockout5 and inherited hu…
Probing the glycosidic linkage: Secondary structures in the gas phase
The functional importance of carbohydrates in biological processes, particularly those involving specific molecular recognition, is immense. Characterizing the three-dimensional (3D) structures of carbohydrates and glycoproteins, and their interactions with other molecules, not least the ubiquitous solvent, water, i…
The controlled introduction of multiple negative charge at single amino acid sites in subtilisin Bacillus lentus.
The use of methanethiosulfonates as thiol-specific modifying reagents in the strategy of combined site-directed mutagenesis and chemical modification allows virtually unlimited opportunities for creating new protein surface environments. As a consequence of our interest in electrostatic manipulation as a…
Altering the specificity of subtilisin Bacillus lentus through the introduction of positive charge at single amino acid sites.
The use of methanethiosulfonates as thiol-specific modifying reagents in the strategy of combined site-directed mutagenesis and chemical modification allows virtually unlimited opportunities for creating new protein surface environments. As a consequence of our interest in electrostatic manipulation as a…
Synthesis of modified proteins via functionalization of dehydroalanine.
Dehydroalanine has emerged in recent years as a non-proteinogenic residue with strong chemical utility in proteins for the study of biology. In this review we cover the several methods now available for its flexible and site-selective incorporation via a variety of complementary chemical and biological techniques…
Post-translational site-selective protein backbone α-deuteration.
Isotopic replacement has long-proven applications in small molecules. However, applications in proteins are largely limited to biosynthetic strategies or exchangeable (for example, N-H/D) labile sites only. The development of postbiosynthetic, C-1H → C-2H/D replacement in proteins could enable probing of…
Post-translational mutagenesis for installation of natural and unnatural amino acid side chains into recombinant proteins.
Methods for installing natural and unnatural amino acids and their modifications into proteins in a benign and precise manner are highly sought-after in protein science. Here we describe a protocol for 'post-translational mutagenesis' that enables the programmed installation of protein side chains through th…