α-amylase crystal growth investigated by in situ atomic force microscopy

Astier, Jean-Pierre; Bokern, D.G.; Lapena, Laurent; Veesler, Stéphane

doi:10.1016/s0022-0248(01)01373-2

Cited by 26 publications

(22 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, colloids and proteins can be used as "model" (model means available in sufficient quantity for many fundamental studies and not representative of all other biological molecules) systems for studying nucleation and crystal growth mechanisms in solution, since their nanosizes, shapes, and interactions enable them to be studied by scattering techniques, such as light scattering or small angle X-ray scattering (SAXS), 22,28,29 and to be observed during crystallization by in situ atomic force microscopy. [30][31][32] In this paper we thoroughly characterize the phase diagram of BPTI in 350 mM KSCN, pH 4.9, as a function of temperature and report SAXS investigations of its liquid-liquid phase separation (LLPS) with the aim of explaining and understanding solid-phase nucleation in the vicinity of a LLPS. We demonstrate that interactions and oligomerization need to be taken together in order to explain the liquid and solid nucleation behavior of BPTI.…”

Section: Introductionmentioning

confidence: 99%

Exploring Bovine Pancreatic Trypsin Inhibitor Phase Transitions

et al. 2006

View full text Add to dashboard Cite

This paper presents an investigation of the phase diagram of BPTI (bovine pancreatic trypsin inhibitor)/350 mM KSCN at pH 4.9 by direct observation and numerical simulations. We report optical microscopy and light and X-ray scattering experiments coupled with theoretical data analysis using numerical tools. The phase diagram is thoroughly determined, as a function of temperature. Two polymorphs are observed by video microscopy and their solubility measured. In this phase diagram, the liquid-liquid phase separation (LLPS) is metastable with respect to the solid-liquid phase separation. Above the T L-L boundary curve, solutions are composed of a mixture of BPTI monomers and decamers. Attractive interactions are stronger between decamers than between monomers. Below the T L-L boundary curve, the dense phase is highly concentrated in protein and composed of BPTI decamers alone. Thus, the driving force for liquid-liquid or liquid-solid phase separation is the attraction between decamers at low pH. The structure factors of the dense phases are characteristic of repulsive dense phases because of a hard sphere repulsion core, meaning that in the dense phase proteins are actually in contact (interparticle distance of 53 Å). In agreement with the Oswald rule of stages, LLPS occurs prior to and impedes the solid nucleation.

show abstract

Section: Introductionmentioning

confidence: 99%

Exploring Bovine Pancreatic Trypsin Inhibitor Phase Transitions

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Step trains were moving at constant velocity and the interstep distance stayed constant over time. Since the scan frequency is known, step velocity can be directly determined from these time‐space images provided that the scan is perpendicular to the step line or the angle between the step line and the scan direction is measured by, for example, also collecting a space‐space image as in the upper part of figure a.…”

Section: Comparison Of Afm and Lcm‐dim For The Measurement Of Crystalmentioning

confidence: 99%

In situ measurement of crystal surface dynamics in pure and contaminated solutions by Confocal Microscopy and Atomic Force Microscopy

Driessche

Sleutel

2013

Crystal Research and Technology

View full text Add to dashboard Cite

Impurities are omnipresent during crystallization from solution, both in the lab and in natural environments. Unravelling the mechanisms of impurity effects during crystal growth contributes to the general understanding of crystallization processes and our ability to control it. One way of obtaining information on the impurity mechanisms is to observe the interaction of these foreign species with the growth sites in situ, if possible at a molecular level. At present several optical based techniques are being employed for this type of research. In this chapter, the application of two popular methods in the area of crystal growth observation, atomic force microscopy and confocal microscopy, will be discussed, pointing out the strong points of each technique illustrated with examples from literature and the authors own work. The aim of this chapter is to show experimentalists, venturing into the field of crystal growth, the wide array of research possibilities these techniques offer for exploring the intriguing world of impurity interactions with crystalline materials.

show abstract

“…The result is different from those reported by other researchers. Astier et al have reported that αamylase aggregates attached to the basal face would crystallize and their subsequent incorporation into growing terraces leaded to the formation of a macro defect in the end [18]. This may be caused by the stronger ability of self-adjustment and reorienting of the microcrystals.…”

Section: Dissolution Of 2d Nucleimentioning

confidence: 99%

In situ AFM investigation of 2D nucleation on the (100) face of KDP

Cheng

Cao

et al. 2009

Cryst. Res. Technol.

View full text Add to dashboard Cite

Surface morphology of the (100) face of potassium dihydrogen phosphate (KDP) crystals which were grown at different supersaturations at 25 °C was investigated by in situ atomic force microscopy (AFM). Various AFM images of 2D nucleation under different growth conditions were presented. It is found that the growth of KDP is controlled by polynuclear nucleation mechanism at the high supersaturation. With reduction of the supersaturation, the growth velocity of 2D nuclei becomes very slow and shows typical anisotropy. It is found that the process of coalescence of 2D nuclei does not lead to defect. The experiments show that the growth mechanism for KDP at 25 °C changes between step flow and 2D nucleation in the supersaturation range of 4.5-5%. The triangular nuclei which are close to equilateral triangle are observed in the experiment at the supersaturation σ=6% for the first time, showing typical anisotropic growth. Through observing the dissolution of 2D nuclei, the dissolving process can be regarded as the reverse process of growth. We also find that the microcrystals landing on the surface at σ=9% would grow and coalesce with each other and there is no observable defect in the coalescence.

show abstract

α-amylase crystal growth investigated by in situ atomic force microscopy

Cited by 26 publications

References 25 publications

Exploring Bovine Pancreatic Trypsin Inhibitor Phase Transitions

Exploring Bovine Pancreatic Trypsin Inhibitor Phase Transitions

In situ measurement of crystal surface dynamics in pure and contaminated solutions by Confocal Microscopy and Atomic Force Microscopy

In situ AFM investigation of 2D nucleation on the (100) face of KDP

Contact Info

Product

Resources

About