A spectrophotometer-based method for crystallization induction time period measurement

Hu, Haiqing; Hale, Tracy K.; Yang, Xiaoye; Wilson, Lori J.

doi:10.1016/s0022-0248(01)01145-9

Cited by 28 publications

(26 citation statements)

References 6 publications

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“…Protein solubility is a complex property that is sometimes difficult to predict. Under typical conditions, proteins are charged macromolecules with long-range interactions, and deviations from the ideality of their solutions is taken into account by means of the activity coefficient γ , commonly estimated from measurements of the second virial coefficient B 22 . This coefficient derives from the virial expansion for the activity coefficient as function of concentration c:…”

Section: Regulation Of Supersaturation Rate In Membrane-assisted Crysmentioning

confidence: 99%

“…14 The equilibrium solubility of globular proteins correlates with the thermodynamic parameter B 22 , 15 that is an integral measure of the strength of protein-protein interactions, the meanforce potential. 14 Accordingly, B 22 can also be defined as…”

Section: Regulation Of Supersaturation Rate In Membrane-assisted Crysmentioning

confidence: 99%

“…In the equation it does not matter what is added to the protein solution to achieve a given value of B 22 ; once the strength of attraction has been achieved, the protein will have the same solubility. Therefore, evaluation of B 22 can give a qualitative measure of the protein-protein interactions in a dilute solution: if B 22 is positive, the net interaction between protein molecules is repulsive; if B 22 is negative, the net interaction between protein molecules is attractive.…”

Section: Regulation Of Supersaturation Rate In Membrane-assisted Crysmentioning

confidence: 99%

“…Therefore, evaluation of B 22 can give a qualitative measure of the protein-protein interactions in a dilute solution: if B 22 is positive, the net interaction between protein molecules is repulsive; if B 22 is negative, the net interaction between protein molecules is attractive. A necessary, but insufficient, requirement for the success of protein crystallization is that values of B 22 vary in a precise range (crystallization slot). 16 It is also known that these values of B 22 correspond to protein-protein interactions that are short-ranged with respect to the size of the protein molecule.…”

Section: Regulation Of Supersaturation Rate In Membrane-assisted Crysmentioning

confidence: 99%

“…This condition typically corresponds to salt concentrations sufficiently large to screen the Coulomb repulsive interaction, so that the Debye screening length is small. 17 For lysozyme, B 22 should be in the interval −2 × 10 −4 mol·mL·g −2 to −8 × 10 −4 mol·mL·g −2 . Progression towards more negative values corresponds to an increase of proteinprotein interactions.…”

Section: Regulation Of Supersaturation Rate In Membrane-assisted Crysmentioning

confidence: 99%

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Crystallization of Biomacromolecules

Drioli¹,

Profio²,

Curcio³

2015

Membrane-Assisted Crystallization Technology

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The crystallization of biomacromolecules by using membrane-assisted crystallization technology is described in this chapter. The discussion will focus on the interest in growing protein crystals and the current difficulties in obtaining them by conventional crystallization methods, the possibility to use MAC for the growth of protein crystals and the influence of controlling the transmembrane flux on crystallization kinetics, the function of polymeric membranes as solid support for heterogeneous nucleation and the correlation between membrane physical properties and the energetics of nucleation, and the effect of forced solution-flow convection on crystallization kinetics and its influence on crystal properties. Interest in Protein CrystallizationThe functions of biomolecules are strictly connected to their three-dimensional molecular structures. Therefore, the determination of the spatial arrangement of atoms or groups of atoms in protein molecules is of fundamental importance for the understanding of their biological activity and for designing new drug molecules that can act at active sites. 1 The 3D structure of proteins can be determined by X-ray or neutron diffraction and nuclear magnetic resonance (NMR) spectroscopy. However, the crystallographic method is the one of choice, especially for molecules that are too large (M.W. > 20 kDa). Crystallography gives a higher resolution, reaching less than 1 Å for particularly complex systems like membrane-protein or viruses. 2 The basic requisite for structure resolution at the atomic level by X-ray diffraction is the availability of well-diffracting crystals of adequate size. 3 193 Membrane-Assisted Crystallization Technology Downloaded from www.worldscientific.com by CHINESE UNIVERSITY OF HONG KONG on 10/09/15. For personal use only.194 Membrane-Assisted Crystallization TechnologyAmong proteins, enzymes are the most efficient known catalysts because of their high substrate specificity. 4 However, their systematic utilization in solution at industrial scale has been rather limited due to their intrinsic labile nature under operative conditions. Poor chemical and mechanical stability at extreme temperatures and pH, high pressure, mechanical stress, and the presence of denaturing solvents and other chemicals, are the factors that have prevented enzymes from being extensively used. Also, in the solid state, proteins are normally characterized by pronounced fragility or shattering under relatively mild conditions. On the other hand, the possibility of producing a large amount of protein crystal with reduced, uniform, and predictable size, slow dissolution kinetics, and high chemical and mechanical stability would have remarkable implications in many biotechnological applications, e.g. for sustained constant rate drug release, in environmental protection applications, in chemical synthesis, etc. 5 In this respect, cross-linked enzyme crystals (CLECs) 6,7 are interesting systems whose production is a relatively simple, fast, and less expensive technique and one that does ...

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Section: Regulation Of Supersaturation Rate In Membrane-assisted Crysmentioning

confidence: 99%

Section: Regulation Of Supersaturation Rate In Membrane-assisted Crysmentioning

confidence: 99%

Section: Regulation Of Supersaturation Rate In Membrane-assisted Crysmentioning

confidence: 99%

Section: Regulation Of Supersaturation Rate In Membrane-assisted Crysmentioning

confidence: 99%

Section: Regulation Of Supersaturation Rate In Membrane-assisted Crysmentioning

confidence: 99%

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Crystallization of Biomacromolecules

Drioli¹,

Profio²,

Curcio³

2015

Membrane-Assisted Crystallization Technology

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Protein Crystallization, Kinetics

Profio

Curcio

Drioli

2010

Encyclopedia of Industrial Biotechnology

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Protein crystallization has become today a fundamental operation in scientific, technological, and industrial sectors. The principal aim of crystal growers is to obtain protein crystals with specific characteristics. Large, well‐diffracting crystals are necessary for tridimensional structure resolution at atomic level by X‐ray diffraction analysis, while smaller, monodispersed in size and uniformly shaped crystals are required in some industrial sectors as, for example, environmental protection, chemical synthesis, and heterogeneous catalysis. However, the production of crystals with opportune properties can only be realized by a fine control of the crystallization kinetics throughout its several steps. The main difficulty in achieving this goal is the poor understanding of the crystallization mechanism in its various aspects, especially for proteins, due to their structural complexity. Generally, theories developed for small molecules crystallization have been extended to proteins. However, although in certain circumstances proteins crystallize by the same mechanisms, they have some of their own peculiarities. These differences can be ascribed to the asymmetric and weak bonding configuration at the protein surface, the tendency to aggregate in n ‐mers, the sensitivity to contaminants and impurities, the formation of precipitates, oils or gels and the low diffusivities in solution. As a result, protein crystallization is a complicated physical–chemical process not fully described by simple theory. In this contribution, the different steps involved during protein crystallization are discussed. These include the initial interaction of protein in solution, their aggregation to form stable nuclei—even when it is promoted by heterogeneous substrates, the growth to macroscopic crystals, and the case of growth in forced solution convection regime.

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RETRACTED ARTICLE: Nucleation and growth rates of lactose as affected by ultrasound in aqueous solutions

Zamanipoor

Dincer

Zisu

et al. 2013

Dairy Sci. & Technol.

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International audienceThe impact of ultrasound on promoting the crystallisation process including an increase in nucleation rate and the formation of more uniform crystals from a large number of substances has been reported in previous studies. This study aimed to investigate the effectiveness of ultrasound in enhancing the crystallisation process of lactose and to model the effects of ultrasonic variables on nucleation rate, growth rate, and size distribution of lactose crystals in aqueous solutions. Ultrasound was applied to the lactose in water solutions at the constant frequency of 20 kHz and at 22 ± 1 °C using an ultrasonic probe. Spectrophotometry and direct microscopy techniques were used to measure the responses under study. The data were analysed by Design Expert software for modelling. The variables that significantly (P < 0.05) affected the responses were lactose concentration and amplitude, with concentration being the most significant. The sonicated sample at the optimal sonication conditions had 10.6 times higher nucleation rate and 5.6 times higher yield as compared to the control. The results of this study emphasised the potential effects of ultrasonic treatment in promoting the nucleation rate and yield in the manufacture of lactose. Furthermore, the fact that sonication time had no significant effect (P > 0.05) on the responses implied that sonication duration can be kept to a minimum to save on energy and costs

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A spectrophotometer-based method for crystallization induction time period measurement

Cited by 28 publications

References 6 publications

Crystallization of Biomacromolecules

Crystallization of Biomacromolecules

Protein Crystallization, Kinetics

RETRACTED ARTICLE: Nucleation and growth rates of lactose as affected by ultrasound in aqueous solutions

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