Structure and thermodynamics of colloidal protein cluster formation: Comparison of square-well and simple dipolar models

Young, Teresa M.; Roberts, Christopher J.

doi:10.1063/1.3238569

Cited by 14 publications

(17 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The protein volume fraction ϕ is therefore equal to N / N s , and is equivalent to the number density in treatments of one-component lattice systems. 58 , 59 , 64 …”

Section: Methodsmentioning

confidence: 99%

Role of Anisotropic Interactions for Proteins and Patchy Nanoparticles

Roberts

Blanco

2014

J. Phys. Chem. B

Self Cite

View full text Add to dashboard Cite

Protein–protein interactions are inherently anisotropic to some degree, with orientation-dependent interactions between repulsive and attractive or complementary regions or “patches” on adjacent proteins. In some cases it has been suggested that such patch–patch interactions dominate the thermodynamics of dilute protein solutions, as captured by the osmotic second virial coefficient (B22), but delineating when this will or will not be the case remains an open question. A series of simplified but exactly solvable models are first used to illustrate that a delicate balance exists between the strength of attractive patch–patch interactions and the patch size, and that repulsive patch–patch interactions contribute significantly to B22 for only those conditions where the repulsions are long-ranged. Finally, B22 is reformulated, without approximations, in terms of the density of states for a given interaction energy and particle–particle distance. Doing so illustrates the inherent balance of entropic and energetic contributions to B22. It highlights that simply having strong patch–patch interactions will only cause anisotropic interactions to dominate B22 solution properties if the unavoidable entropic penalties are overcome, which cannot occur if patches are too small. The results also indicate that the temperature dependence of B22 may be a simple experimental means to assess whether a small number of strongly attractive configurations dominate the dilute solution behavior.

show abstract

“…The protein volume fraction ϕ is therefore equal to N / N s , and is equivalent to the number density in treatments of one-component lattice systems. 58 , 59 , 64 …”

Section: Methodsmentioning

confidence: 99%

Role of Anisotropic Interactions for Proteins and Patchy Nanoparticles

Roberts

Blanco

2014

J. Phys. Chem. B

Self Cite

View full text Add to dashboard Cite

show abstract

“…6 We set λ = 1.2 in our calculations, motivated by the recognition that proteins typically possess interactions of short range. 6,[16][17][18] To these expressions we add the electrostatic free energies f es d of each d-dimensional assembly. We calculated these free energies using the Poisson-Boltzmann (PB) equation,…”

Section: Modelmentioning

confidence: 99%

Electrostatics and aggregation: How charge can turn a crystal into a gel

Schmit

Whitelam

Dill

2011

The Journal of Chemical Physics

View full text Add to dashboard Cite

The crystallization of proteins or colloids is often hindered by the appearance of aggregates of low fractal dimension called gels. Here we study the effect of electrostatics upon crystal and gel formation using an analytic model of hard spheres bearing point charges and short range attractive interactions. We find that the chief electrostatic free energy cost of forming assemblies comes from the entropic loss of counterions that render assemblies charge-neutral. Because there exists more accessible volume for these counterions around an open gel than a dense crystal, there exists an electrostatic entropic driving force favoring the gel over the crystal. This driving force increases with increasing sphere charge, but can be counteracted by increasing counterion concentration. We show that these effects cannot be fully captured by pairwise-additive macroion interactions of the kind often used in simulations, and we show where on the phase diagram to go in order to suppress gel formation.

show abstract

“…Recently, the use of nucleation agents to accelerate the crystallization of proteins was demonstrated [13]. In addition, protein modeling techniques to capture kinetics and thermodynamics of the crystallization on such surfaces on the colloidal scale are being developed [14]- [16]. Despite the developments summarized above, there is a continuous need for detailed investigation of surfaces that are ideal for the growth of diffraction quality protein crystals in a rapid manner.…”

Section: Introductionmentioning

confidence: 99%

Crystallization of Lysozyme on Metal Surfaces Using a Monomode Microwave System

Mauge-Lewis¹,

Gordon²,

Syed³

et al. 2016

Nano BioMed ENG

View full text Add to dashboard Cite

The effect of metal surfaces on the crystallization of lysozyme using the Metal-Assisted and Microwave-Accelerated Evaporative Crystallization (MA-MAEC) technique and a monomode microwave system is described. Our microwave system (is called the iCrystal system hereafter for brevity) is comprised of a 100 W variable power monomode microwave source, a monomode cavity, fiber optic temperature probes and digital cameras. Crystallization of lysozyme (a model protein) was conducted using the iCrystal system on four different types of circular crystallization plates with 21-well sample capacity (i.e., crystallization plates): (i) blank: a continuous surface without a metal, (ii) silver nanoparticle films (SNFs): a discontinuous metal film, (iii) iron nano-columns: a semicontinuous metal film, and (iv) indium tin oxide (ITO): a continuous metal film. Lysozyme crystals grown on all crystallization plates were characterized by X-ray crystallography and found to be X-ray diffraction quality. The use of iron nano-columns afforded for the growth of largest number of lysozyme crystals with a narrow size distribution. ITO-modified crystallization plates were deemed to be best of all the crystallization plates based on the observations that lysozyme crystals were grown at the shortest time (370 ± 36 minutes) with a narrow size distribution up to 460 m in size.

show abstract

Structure and thermodynamics of colloidal protein cluster formation: Comparison of square-well and simple dipolar models

Cited by 14 publications

References 34 publications

Role of Anisotropic Interactions for Proteins and Patchy Nanoparticles

Role of Anisotropic Interactions for Proteins and Patchy Nanoparticles

Electrostatics and aggregation: How charge can turn a crystal into a gel

Crystallization of Lysozyme on Metal Surfaces Using a Monomode Microwave System

Contact Info

Product

Resources

About