Enhancement and suppression of protein crystal nucleation due to electrically driven convection

The use of lipidic cubic phases as crystal nucleation and growth matrices is becoming popular and has yielded crystals of soluble and membrane proteins. So far, all of the membrane proteins crystallized by this method have been colored. This feature has facilitated the detection of the often encountered microcrystals in initial screening rounds. Indeed, small colorless protein crystals have poor optical contrast as a result of the small differences in refractive index of the protein crystal and the surrounding lipidic cubic phase. While a perfect preparation of a lipidic cubic phase is transparent and optically isotropic, in a crystallization setup it frequently disguises crystals due to cracks, inclusions, surface distortions and phase boundaries. Here, several specialized microscopic techniques and illumination conditions are compared and it is found that sufficient contrast is generated by cross polarization microscopy and by Hoffman modulation contrast microscopy for the detection of colorless protein crystals.

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Fractal Aggregates in Protein Crystal Nucleation

The Journal of Physical Chemistry B ◽

10.1021/jp8002728 ◽

2008 ◽

Vol 112 (15) ◽

pp. 4725-4730 ◽

Cited By ~ 10

Author(s):

Bin Chen ◽

Ricky B. Nellas ◽

Samuel J. Keasler

Keyword(s):

Crystal Nucleation ◽

Protein Crystal ◽

Fractal Aggregates

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Control of Protein Crystal Nucleation and Growth Using Stirring Solution

Japanese Journal of Applied Physics ◽

10.1143/jjap.43.l1442 ◽

2004 ◽

Vol 43 (No. 11A) ◽

pp. L1442-L1444 ◽

Cited By ~ 6

Author(s):

Ai Niino ◽

Hiroaki Adachi ◽

Kazufumi Takano ◽

Hiroyoshi Matsumura ◽

Takayoshi Kinoshita ◽

...

Keyword(s):

Nucleation And Growth ◽

Crystal Nucleation ◽

Protein Crystal

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Fluorescence studies of protein crystal nucleation

10.1117/12.401612 ◽

2000 ◽

Cited By ~ 1

Author(s):

Marc L. Pusey ◽

John Sumida

Keyword(s):

Crystal Nucleation ◽

Protein Crystal ◽

Fluorescence Studies

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Enhancement of nucleation of protein crystals on nano-wrinkled surfaces

Faraday Discussions ◽

10.1039/c5fd00119f ◽

2016 ◽

Vol 186 ◽

pp. 187-197 ◽

Cited By ~ 4

Author(s):

Praveen K. Bommineni ◽

Sudeep N. Punnathanam

Keyword(s):

Free Energy ◽

Protein Concentration ◽

Protein Crystallization ◽

Crystal Nucleation ◽

Protein Crystal ◽

Protein Crystals ◽

Free Energy Barrier ◽

High Quality ◽

High Quality Protein ◽

Sinusoidal Surface

The synthesis of high quality protein crystals is essential for determining their structure. Hence the development of strategies to facilitate the nucleation of protein crystals is of prime importance. Recently, Ghatak and Ghatak [Langmuir 2013, 29, 4373] reported heterogeneous nucleation of protein crystals on nano-wrinkled surfaces. Through a series of experiments on different proteins, they were able to obtain high quality protein crystals even at low protein concentrations and sometimes without the addition of a precipitant. In this study, the mechanism of protein crystal nucleation on nano-wrinkled surfaces is studied through Monte Carlo simulations. The wrinkled surface is modeled by a sinusoidal surface. Free-energy barriers for heterogeneous crystal nucleation on flat and wrinkled surfaces are computed and compared. The study reveals that the enhancement of nucleation is closely related to the two step nucleation process seen during protein crystallization. There is an enhancement of protein concentration near the trough of the sinusoidal surface which aids in nucleation. However, the high curvature at the trough acts as a deterrent to crystal nucleus formation. Hence, significant lowering of the free-energy barrier is seen only if the increase in the protein concentration at the trough is very high.

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