Determination of the phase diagram for the crystallization of L-asparaginase II by a turbidity technique - part II. -MPD and crystallography studies-

The phase diagram for the crystallization of L-asparaginase II including the metastable zone width (MZW), in the presence of PEG6000 and ethanol, respectively, has been studied by an online turbidity technique out of the crystallization in solution (see part I of this work [1]). Here this paper describes a further investigation on constructing a phase diagram including MZW for the crystallization of L-asparaginase II with a different precipitant agent of 2-methyl-2, 4-pentandiol (MPD). Along with the phase diagram, the single crystal X-ray data were successfully collected at 100K from a crystal formed in the presence of 26% (v/v) MPD. The crystals indicate an orthorhombic form and belong to the space group of P212121 with the unit cell parameters a = 93.9, b = 125.77, c = 151.75A. The crystal diffracted up to a resolution of 2.88 A.