The growth and dissolution rates of glucose isomerase crystals (11 0 11 face) were measured in situ at 0.1 and 100 MPa. From these data, we determined that the solubilities at 25 degreesC 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 (or ln(C/C-e), C = the concentration of glucose isomerase, C-e = the solubility) and temperature (T = 25 degreesC), 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.