Yale University

Yale researchers propose an innovative approach to achieve a long-standing goal in the field of chemistry – the construction of bona fide artificial enzymes.  It will apply methods from four related fields: organic chemistry, carbohydrate chemistry, enzymology, and biophysics.  Catalytic substrates known as β-peptides bundles will be created to mimic carbohydrate-processing enzymes.  The investigators will optimize three steps that define the catalytic cycle: (1) substrate binding, (2) chemical reactivity, and (3) product release.  To optimize substrate binding, β peptide bundles will be assembled that contain an extended phenyl boronic acid “docking site.”  To optimize chemical reactivity, the researchers will assemble in parallel β-peptide bundles appended with 2-3 carboxylate side chains (of various structure and acidity) in positions that mimic their spacing in carbohydrate processing enzymes.  Optimizing the product release will make use of traditional or stopped-flow kinetics methods as well as surface plasmon resonance.  These features will then be combined into first-generation catalysts to optimize their properties through the application of combinatorial, catalytic, activity-based screens.  These catalysts will then be optimized through the application of combinatorial, catalytic activity-based screens and studied in detail using both biophysical (calorimetry, crystallography) and spectroscopic (NMR) methods to identify and explore relationships between catalytic efficiency, cooperative folding, and protein dynamics.