Nd K. W. All authors have provided approval towards the final version from the manuscript. The authors declare no competing economic interest. Supporting Facts Dependence of spin lattice relaxation price on TEMPOL concentration in low temperature, homogeneous 60 (w/v) sucrose glass. This material is offered free of charge by means of the internet at http://pubs.acs.org.Chen et al.Pagebehavior of the sucrose-water system upon freezing, which has been studied for over five decades,4 is described by the temperature-composition (T-c) state diagram in Figure 1. The T-c diagram is derived principally from calorimetric measurements.five Figure 1 shows that, with increasing sucrose concentration, the liquidus curve (coexistence of water-ice crystals and fluid sucrose-water) passes by way of a theoretical eutectic point, Te, where sucrose crystallization is kinetically restricted by the high viscosity on the sucrose-water mixture. The liquidus curve terminates in the glass transition temperature, Tg’, which corresponds to the value of 80 ? (w/w) [120 ? (w/v)] sucrose.6 The enduring interest inside the description with the physical properties of sugar-water options has been driven by the central function of sugars in meals and biological sample preservation applications in industry and medicine.7-9 The detailed, microscopic characterization of sugar modulation of solventprotein structural and dynamical coupling is also crucial for the basic understanding of protein function.N-Methyltetrahydro-2H-pyran-4-amine Chemscene 10-12 Throughout “slow” (103 K/s) cooling of an unsaturated sucrose-water solution, a trajectory to higher sucrose concentration along the “equilibrium” liquidus curve of Figure 1 is correctly reproduced within the mesodomain, as water removal from the mesodomain volume by water-ice crystal development is driven by the lowering T. As T continues to lower, more water-ice forms, the mesodomain volume decreases additional, the sucrose concentration within the mesodomain increases, as well as the mesodomain ultimately types a glass, at Tg”Tg’. The position on the productive liquidus curve below finite cooling prices, and the worth of your helpful glass transition temperature, Tg”, rely on the cooling price and sample thermal history, as depicted by the dotted liquidus curve in Figure 1. In the slower cooling price limit (about, 102 K/s), the sucrose in the mesodomain achieves the “maximally freezeconcentrated” value of 80 ? (w/w) [120 ? (w/v)] sucrose,6 plus the mesodomain types a glass, with Tg’241 K.H-Lys(Fmoc)-OH Chemical name 1 In contrast, a homogeneous glassy state over the complete sample volume is developed by cooling of concentrated or super-saturated sugar solutions (Figure 1).PMID:24278086 For the cooling rates of 10 K/s or decrease, which might be utilised within the studies reported right here, the heterogeneous frozen state is formed at concentrations of 50 (w/v), and also the homogeneous glass is formed for concentrations of 50 (w/v) sugar. At ultra speedy cooling rates (104 K/ s), glass formation supersedes homogeneous and inhomogeneous nucleation. Ultra-fast cooling research show that pure water vitrifies at 138 K.13 TEMPOL, a reasonably compact (productive diameter, roughly 7 ?, paramagnetic (S=1/2) nitroxide molecule, is also excluded from the water-ice crystalline domains upon cooling of aqueous options. Thus, TEMPOL can be a localized, in situ electron paramagnetic resonance (EPR) spin probe of the mesodomain.14 TEMPOL has been applied to characterize the dynamics of vitreous pure water14, 15 and aqueous glycerol solutions14 at low temperatures. These s.
