2 research outputs found

    Aza-Glycine Induces Collagen Hyperstability

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    Hydrogen bonding is fundamental to life on our planet, and nature utilizes H-bonding in nearly all bio­molecular interactions. Often, H-bonding is already maximized in natural bio­polymer systems such as nucleic acids, where Watson–Crick H-bonds are fully paired in double-helical structures. Synthetic chemistry allows molecular editing of bio­polymers beyond nature’s capability. Here we demonstrate that substitution of glycine (Gly) with aza-glycine in collagen may increase the number of inter­facial cross-strand H-bonds, leading to hyper­stability in the triple-helical form. Gly is the only amino acid that has remained intolerant to substitution in collagen. Our results highlight the vital importance of maximizing H-bonding in higher order biopolymer systems using minimally perturbing alternatives to nature’s building blocks

    Ultrafast Solvation Dynamics and Vibrational Coherences of Halogenated Boron-Dipyrromethene Derivatives Revealed through Two-Dimensional Electronic Spectroscopy

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    Boron-dipyrromethene (BODIPY) chromophores have a wide range of applications, spanning areas from biological imaging to solar energy conversion. Understanding the ultrafast dynamics of electronically excited BODIPY chromophores could lead to further advances in these areas. In this work, we characterize and compare the ultrafast dynamics of halogenated BODIPY chromophores through applying two-dimensional electronic spectroscopy (2DES). Through our studies, we demonstrate a new data analysis procedure for extracting the dynamic Stokes shift from 2DES spectra revealing an ultrafast solvent relaxation. In addition, we extract the frequency of the vibrational modes that are strongly coupled to the electronic excitation, and compare the results of structurally different BODIPY chromophores. We interpret our results with the aid of DFT calculations, finding that structural modifications lead to changes in the frequency, identity, and magnitude of Franck–Condon active vibrational modes. We attribute these changes to differences in the electron density of the electronic states of the structurally different BODIPY chromophores
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