1,721,126 research outputs found
Amphiphilic a-helix mimetics based on a benzoylurea scaffold
No full textThe design and synthesis of amphiphilic benzoylurea ?-helix mimetics is described. These conformationally constrained molecules allow for the correct angular and spatial projection of hydrophobic and hydrophilic groups and thus the reproduction of side-chains on both faces of an ?-helix
An alpha-helical peptidomimetic scaffold for dynamic combinatorial library formation
No full textA novel oligobenzamide-based alpha-helix mimetic was designed and synthesised with either imine or hydrazone functionalities that serve both to pre-organise the side-chain vectors to mimic the i, i + 4 and i + 7 residues of an alpha-helix, and to allow for the facile creation of dynamic libraries
Super-secondary structure peptidomimetics: design and synthesis of an a–a hairpin analogue
No full textThe ?–? helix motif presents key recognition domains in protein–protein and protein–oligonucleotide binding, and is one of the most common super-secondary structures. Herein, we describe the design, synthesis and structural characterisation of an ?–? hairpin analogue based on a tetra-coordinated Pd(II) bis-(iminoisoquinoline) complex as a template for the display of two ?-helix mimics. This approach is exemplified by the attachment of two biphenyl peptidomimetics to reproduce the side chains of the i and i+4 residues of two helices
Unpicking the determinants of amide NH••O=C hydrogen bond strength with diphenylacetylene molecular balances
No full textHydrogen bonding plays an essential part in dictating the properties of natural and synthetic materials. Secondary amides are well suited to cross–strand interactions through the display of both hydrogen bond donors and acceptors and are prevalent in polymers such as proteins, nylon, and Kevlar(TM). In attempting to measure hydrogen bond strength and to delineate the stereoelectronic components of the interaction, context frequently becomes vitally important. This makes molecular balances – systems in which direct comparison of two groups is possible – an appealing bottom up approach that allows the complexity of larger systems to be stripped away. We have previously reported a family of single molecule conformational switches that are responsive to diverse stimuli including Brønsted and Lewis acids, anions, and redox gradients. In this work we assess the ability of the scaffold, based on a 2,6-disubstituted diphenylacetylene, to measure accurately the difference in hydrogen bond strength between variously functionalised amides. In all of the examples investigated hydrogen bond strength closely correlate to measures of Brønstead acidity suggesting that the scaffold is well-suited as a platform for the accurate determination of bond strength in variously substituted systems
In celebration of the 60th birthday of Professor Andrew D. Hamilton FRS
No full textAn on-line collection of articles celebrating the 60th birthday of Professor Andrew D. Hamilton FRS has been published featuring contributions from students and colleagues past and present. This article hopes to provide an insight into the rise of a star in molecular recognition, ground breaking discoveries, and on a more light-hearted note, some fond reminiscences of research in Cambridge, Princeton, Pittsburgh, Yale and Oxford
a-helix mimetics: outwards and upwards
No full text?-Helices are common secondary structural elements forming key parts of the large, generally featureless interfacial regions of many therapeutically-relevant protein–protein interactions (PPIs). The rational design of helix mimetics is an appealing small-molecule strategy for the mediation of aberrant PPIs, however the first generation of scaffolds presented a relatively small number of residues on a single recognition surface. Increasingly, helices involved in PPIs are found to have more complex binding modes, utilizing two or three recognition surfaces, or binding with extended points of contact. To address these unmet needs the design and synthesis of new generations of multi-sided, extended, and supersecondary structures are underway
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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