A simple technique for consistently obtaining large single crystals of hen egg-white lysozyme in a concentration gradient of NiCl₂

Abstract

A simple protocol is reported for consistently obtaining large single crystals of hen egg‐white lysozyme (HEWL) greater than 2 mm in the longest dimension. Comparative crystallization experiments with different sources of HEWL showed that the simple addition of glass capillaries, `crystal hangers', reduced excessive nucleation and resulted in large single crystals regardless of the commercial source of HEWL.

Thermal and Solution Stability of Lysozyme in the Presence of Sucrose, Glucose, and Trehalose

“…Lysozyme has been used as a model protein for this study, since its biophysical properties are well understood and the specific contribution of the sugar to its stability over a range of solution conditions can easily be compared with that of the native protein. Lysozyme is a widely studied protein due to its rich phase behavior 17,18 including crystallization, 19 liquid−liquid phase separation, 20−22 and the formation of equilibrium clusters 23−25 and gels. 24 The solution behavior of lysozyme is also well understood in terms of its interaction with salt ions.…”

Enhancing the volume and the optical quality of hen egg-white lysozyme crystals by coupling the salt concentration gradient crystallization method with a magnetic field

“…Divalent paramagnetic cations show a tendency to grow larger crystals than ordinary diamagnetic salts, and Mn 2+ ions can make crystals that look optically better in a magnetic field (Yin et al, 2003). The 'crystal hanger' acts as an 'artificial' nucleation site that induces crystallization around the capillaries, leading to the suppression of nucleation on the walls of the tube and resulting in large single crystals (Magay & Yoon, 2011). While the 'crystal hanger' regulates excessive nucleation, the magnetic field controls the optical quality and shapes of the crystals.…”

“…Glass capillaries (the 'crystal hanger'; Fig. 1c) were used to suppress nucleation on the walls of the tubes (Magay & Yoon, 2011). After protein solutions had been prepared, the tubes were immediately inserted into the magnetic device, to apply a magnetic field during the protein crystal growth, and the whole assembly was placed into an incubator.…”

Crystallization of lysozyme with (R)-, (S)- and (RS)-2-methyl-2,4-pentanediol

“…We chose this proteinprecipitant pair for three reasons. Firstly, lysozyme is the most widely examined protein in crystallization and structural analysis studies Liang et al, 2013;Magay & Yoon, 2011;Tu et al, 2014). Secondly, MPD is a chiral molecule that is one of the most common additives in protein crystallization (Anand et al, 2002), although it has been used exclusively as the racemate.…”