Figure 1.

SDS/PAGE of inclusion bodies from E. coli pET3MP. Labeling below the gels indicates the concentration of urea and the sample identity as unfractionated (u), supernatant (sup; s), or pellet (pel; p). * indicate a high-speed pellet or high-speed supernatant. Lanes 1 and 2 contain whole-cell lysates before and after MP gene induction in E. coli pET3MP, respectively. Lanes 3–8, inclusion bodies isolated by using a previous protocol (ref. 25; labeled older). Lane 3, soluble in buffer L with 4 M urea (25). Lane 4, insoluble in buffer L with 4 M urea but soluble in buffer L with 8 M urea. Lane 5, material from lane 3 in buffer L without urea (25). Lanes 6–8, sample from lane 5 fractionated via centrifugation; lane 6, low-speed (15,000 g) pellet; lane 7, high-speed (100,000 g) pellet; lane 8, high-speed supernatant. Lane 9, inclusion bodies isolated by using the protocol described in this paper (labeled new). SDS/PAGE gels were stained with Coomassie. Molecular mass standards (M_r) in kDa. Lanes 1 and 2 were from one gel, and lanes 3–9 were from another gel. The order of lanes 3 and 4 was changed for clarity.