High-pressure acceleration of the growth kinetics of glucose isomerase crystals.
The growth and dissolution rates of glucose isomerase crystals ({1 0 1} face) were measured in situ at 0.1 and 100 MPa. From these data, we determined that the solubilities at 25 degrees C were C(e) = 3.1 +/- 0.9 and 2.6 +/- 0.5 mg mL(-1) at 0.1 and 100 MPa, respectively. At the same supersaturation of sigma = 2.5 (sigma identical with ln(C/C(e)), C = the concentration of glucose isomerase, C(e) = the solubility) and temperature (T = 25 degrees C), the growth rate under 100 MPa was 7.6 times larger than that under 0.1 MPa. This result shows, for the first time, a kinetic acceleration of the growth rates of protein crystals with increasing pressure. The growth rates vs sigma data fitted well with a two-dimensional nucleation growth model of a polynucleation type. The fitting results indicate that the acceleration is mainly due to the decrease in the molecular surface energy of the glucose isomerase crystal with pressure.
Suzuki
Yoshihisa
Y
Department of Chemical Science and Technology, Faculty of Engineering, The University of Tokushima, 2-1 Minamijosanjima, Tokushima 770-8506, Japan. toshiki@nict.go.jp
Sazaki
Gen
G
Matsui
Takuro
T
Nakajima
Kazuo
K
Tamura
Katsuhiro
K
D019747:Aldose-Ketose Isomerases / Q000737:chemistry*; D002627:Chemistry, Physical / Q000379:methods*; D003460:Crystallization; D007700:Kinetics; D008956:Models, Chemical; D011312:Pressure; D012995:Solubility; D013302:Streptomyces / Q000201:enzymology; D013696:Temperature
D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase