Characterizing Protein Crystal Nucleation A dissertation presented to the Faculty of the Graduate School of Arts and Sciences of Brandeis University, Waltham, Massachusetts by Sathish V. Akella We developed an experimental microfluidic based technique to measure the nucleation rates and successfully applied the technique to measure nucleation rates of lysozyme crystals. The technique involves c...

Ice nucleation temperatures of individual leaves were determined by a tube nucleation test. With this assay, a direct quantitative relationship was obtained between the temperatures at which ice nucleation occurred on individual oat (Avena sativa L.) leaves and the population sizes of ice nucleation active (INA) bacteria present on those leaves. In the absence of INA bacteria, nucleation of sup...

The status of our understanding of nucleation is reviewed. Both general aspects of nucleation and those specific to protein solutions and colloidal suspensions are considered. We conclude that although we have what we believe is a quite good understanding of homogeneous nucleation in one simple system, hard-sphere colloids, in other systems there are still basic questions that are unanswered. F...

(1) Calcium greatly increased crystallization of monosodium urate in otherwise pure water, by enhancing both nucleation and growth. (2) Acid accelerated urate nucleation, both by its direct action and indirectly by increasing the free calcium in physiological fluids. (3) Synovial fluid from one gouty patient accelerated urate nucleation, while that from one rheumatoid patient inhibited nucleati...

A new model for homogeneous nucleation of structural phase transformations, which can span the range of nucleation from classical to nonclassical, is presented. This model is extended from the classical nucleation theory by introducing driving-force dependencies into the interfacial free energy, themisfit strain energy, and the nucleus chemical free-energy change in order to capture the nonclas...

Realistic mechanistic pictures of β-hairpin formation, offering valuable insights into some of the key early events in protein folding, are accessible through short designed polypeptides as they allow atomic-level scrutiny through simulations. Here, we present a detailed picture of the dynamics and mechanism of β-hairpin formation of Chignolin, a de novo decapeptide, using extensive, unbiased m...

Despite recent advances in monitoring nucleation from a vapor at close-to-molecular resolution, the identity of the critical cluster, forming the bottleneck for the nucleation process, remains elusive. During past twenty years, the first nucleation theorem has been often used to extract the size of the critical cluster from nucleation rate measurements. However, derivations of the first nucleat...

Recent experimental [Diao et al., J. Am. Chem. Soc. 2011 133, 3756.] and simulation results [Sear, J. Phys. Cond. Matt. 2012 24, 052205.] are not consistent with a nucleation rate that is in the thermodynamic limit. This has consequences, if the rate is not in the thermodynamic limit, the time for nucleation will not necessarily scale as one over system size. Here, I show how to analyse data fo...

in this research, a sol-modified composite electrodeposition technique that combines the sol-gel method with the conventional electrodeposition process was utilized to deposit ni-tio2 nanocomposite coatings. cyclic voltammetry and chronoamperometry techniques were applied to study the influence of the tio2 sol concentration on the deposits’ electrochemical behavior. the results clearly showed t...