Crystallization of human tumour necrosis factor
Walker N., Marcinowski S., Hillen H., Mächtle W., Jones Y., Stuart D.
Crystals of recombinant human tumour necrosis factor, an 157 amino acid protein expressed in Escherichia coli, have been obtained that are suitable for a full structure determination. A dramatic increase in crystal size was obtained with the addition of the non-ionic detergent β-octyl glucoside. The crystals belong to the trigonal space group P3121 with unit cell dimensions a=b=166.0 å and c=93.0 å, and diffract to 2.9 å. Crystal density measurements indicated a solvent content of close to 65%. Since TNF has been proposed to exist at the trimer in solution, this is consistent with an arrangement of two independent trimers, i.e. six molecules, in the asymmetric unit. © 1990.