Aqueous poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide) (PEO109−PPO41−PEO109) copolymers are nonionic surfactants that self-organize to form aggregate structures with increasing temperature or concentration. We have studied two concentrations over a range of temperatures so the in one three microphases: unimers, micelles, hydrogels formed from body centered cubic aggregates micelles. Three different coumarin dyes were chosen based on their hydrophobicity regions could be...

A new twist: multi-probe and multi-frequency approach is shown for dissecting the folding dynamics of individual protein structural elements. In response to a temperature jump 310-helix (blue in picture) miniprotein Trp-cage unfolds before global unfolding protein, whereas formation cage structure depends on α-helix (red).

Miniproteins provide useful model systems for understanding the principles of protein folding and design. These proteins also serve as test cases theories folding, their small size ultrafast kinetics put them in a regime time scales that is now becoming accessible to molecular dynamics simulations. Previous estimates have suggested "speed limit" on order 1 μs. Here computationally designed mutant 20-residue Trp-cage miniprotein, Trp2-cage, presented. The Trp2-cage has greater stability than...

Backbone−backbone hydrogen bonds are a common feature of native protein structures, yet their thermodynamic and kinetic influence on folding has long been debated. This is reflected by the disparity between current models, which place bond formation at different stages along trajectory. For example, previous studies have suggested that denatured state villin headpiece subdomain contains residual helical structure may provide bias toward folded confining conformational search associated with...

Using circular dichroism spectroscopy, we show evidence of unusual folding behaviour for several designed peptides in neat ionic liquid. Helical peptides, AKA(2) and Trp-cage, exhibit heat-induced folding, with stable helical structure persisting to 96 °C, whereas the β-hairpin Trpzip4 is destabilized by [C(4)mpy][Tf(2)N].

The folding mechanism and dynamics of a helical protein may strongly depend on how quickly its constituent α-helices can fold independently. Thus, our understanding the problem be greatly enhanced by systematic survey rates individual α-helical segments derived from their parent proteins. As first step, we have studied relaxation kinetics central helix (L9:41-74) ribosomal L9 bacterium Bacillus stearothermophilus, in response to temperature-jump (T-jump) using infrared spectroscopy. L9:41-74...

Eine überraschende Wendung: neuartige Multisonden- und Multifrequenzmethode ermöglicht die Untersuchung der Faltungsdynamik individueller Proteinstrukturelemente. Ausgelöst durch einen Temperatursprung entfaltet sich 310-Helix (blau im Bild) des Miniproteins Trp-cage vor globalen Entfaltung Proteins, während Bildung Käfigstruktur von Faltung α-Helix (rot) abhängt. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents peer-reviewed, but...

The College of New Jersey's Chemistry Department and School Science have been strategically transforming our teaching, learning, mentoring environments for over a decade through programs that are targeted toward "new majority" students: low-income, first generation, historically marginalized races ethnicities. Recently, we shifted from target small number students to focus on systemic structural changes create inclusive excellence. We formalized work in Theory Change (ToC) emphasizes...

In an attempt to determine how the folding dynamics of multistranded β-sheets vary with strand number, we have studied temperature-induced relaxation kinetics a four-stranded β-sheet, DPDPDP. Our results show that thermally induced DPDPDP occurs on nanosecond time scale; however, comparison current those obtained sequence-related, three-stranded β-sheet suggests increasing number from three four increases free energy barrier by minimum 0.8 kcal/mol, depending mechanism. Therefore, these...

Structural perturbation has been extensively used in protein folding studies because it yields valuable conformational information regarding the process. Here we have N-terminal truncation on a cross-linked variant of GCN4-p1 leucine zipper, aiming to develop better understanding mechanism coiled-coil motif. Our results indicate that removing first heptad repeat this coiled coil significantly decreases free energy barrier and maximum rate (2.0 ± 0.3 μs)-1, which is ∼50 times faster than...

Small proteins often fold in an apparent two-state manner with the absence of detectable early-folding intermediates. Recently, using native-state hydrogen exchange, intermediates that exist after rate-limiting transition state have been identified for several proteins. However, little is known about folding kinetics from these post-transition to their corresponding native states. Herein, we used protein engineering and a laser-induced temperature-jump (T-jump) technique investigate this...

The effect of choline chloride on the conformational dynamics 11‐mer repeat unit P1LEA‐22 group 3 Late Embryogenesis Abundant (G3LEA) proteins was studied. Circular dichroism data aqueous solutions revealed that peptide favors a polyproline II (PPII) helix structure at low temperature, with increasing temperature promoting gain unstructured conformations. Furthermore, increases in sample FeCl or concentrations causes PPII helical temperature. potential role intrinsically disordered and G3LEA...

Die Faltungsdynamik individueller Proteinstrukturelemente wird mit einer Methode untersucht, die mehrere Sonden und Frequenzen nutzt. In ihrer Zuschrift auf S. 11076 ff. erzielen M. R. Bunagan, F. Gai et al. ihrem Verfahren eine deutlich verbesserte Strukturauflösung bei der kinetischen Untersuchung Faltungsdynamik. Anwendung dieser das Miniprotein Trp-cage liefert neue Einblicke in den Faltungsmechanismus dieses ausgiebig untersuchten Proteins.