Comparison of the Crystallization Kinetics of Canavalin and Lysozyme

Abstract

Using dilatometry, we examined the crystallization kinetics of the jack bean storage protein, canavalin. We found that the kinetic rate law is first order in the supersaturation. At pH values above the pI = 5.2, where the protein is negatively charged, the apparent rate constant, k, increases as the pH approaches the pI, decreases with increasing temperature, and increases with increasing salt concentration. The rate constant is essentially independent of the initial protein concentration. Precisely the same patterns of behavior were observed by Kim et al. [Mol. Phys. 2003, 101, 2677−2686] in dilatometer experiments involving the crystallization of lysozyme even though lysozyme molecules are positively charged under crystal growth conditions. By combining dimensional analysis with a simple theory of protein crystal nucleation and growth, we show that k ≈ ω/c s, where ω is the rate coefficient that controls the rate of advance of the crystal facets, and c s is the solubility of the protein in the growth solution. We determined the dependence of ω upon temperature and salt concentration by analyzing the observations of Forsythe and Pusey [J. Cryst. Growth 1994, 139, 89−94] of the rate of advance of the facets of growing lysozyme crystals. To the extent that our data overlap that of Forsythe and Pusey, we are able to show for both canavalin and lysozyme that the dependence of k, ω, and c s upon these variables is consistent with k ≈ ω/c s.

Nucleation and particle growth with fluctuating rates at the intermediate stage of phase transitions in metastable systems

“…This behaviour reflects a smooth transition between the intermediate, initial and final stages of the process. [32]. The parameters in expression (3.15) were u 0 = 10 −1 , p = 4.5.…”

Theory of the intermediate stage of crystal growth with applications to protein crystallization

“…Supersaturation decay data have been reported for the proteins lysozyme [6] and canavalin [7]. In the case of lysozyme, Kim et al [6] proposed that the crystals grow heterogeneously from fixed nucleation sites.…”

The crystallization of lysozyme in the system of ionic liquid [BMIm][BF4]‐water

“…It was conceivable that the gradual change of conditions (enroute to equilibrium) might be the crucial factor for the formation of crystals. Caraballo [36] and Taleb [37] researched kinetics and nucleation procedure of lysozyme under different conditions. Generally, high supersaturation corresponded to high growth rate, and the solution reaching to supersaturation slowly was good for forming high quality single crystals.…”