CRYSTALLIZATION AND PRELIMINARY-X-RAY ANALYSIS OF LEUKEMIA INHIBITORY FACTOR

Leukemia inhibitory factor (LIF) is a polyfunctional molecule with significant and diverse biological activities. LIF is a glycoprotein secreted by a number of different cell types in vitro. It is induced in fibroblasts, lymphocytes, monocytes and astrocytes by various inducers such as serum, TNF, interleukin-IP and EGF. Due to extensive and variable glycosylation the molecular weight can range from 38 to 67 kDA. The biological functions of LIF are mediated through a receptor and a signal transducer, gp 1 30, which is also used by factors like interleukin-6 (IL-6), cilliary neurotropic factor (CNTF), and oncostatin M (OSM). Here, we report the crystallization of the non-glycosylated human-like LIF expressed in E. coli. The present crystals diffract to 2.0 angstrom using synchrotron radiation. They belong to the monoclinic space group C2, and the cell dimensions are a = 61.5 angstrom, b = 45.3 angstrom , c = 77.7 angstrom and beta = 112.3-degrees.