. The ligated product was transformed into E. coli BL21 (DE3) pLysS and the positive clones obtained by selection
medium (LB agar supplemented with ampicillin 50 lg/ml) were
further confirmed by PCR and restriction analysis. Transformants were cultured 12 h in LB medium with ampicillin (50 lg/ml) at
37 C. It was subcultured into fresh LB/ampicillin medium, grown several hours at 37 C to an OD590 = 0.4 and then induced using IPTG. Before harvesting, the cells were incubated for 6 h at 37 C. To analyze the induced protein, an equivalent of 1.0 ml of cells was resuspended in 0.1 ml of cracking buffer and heated at
100 C for 5 min immediately prior to loading a 20 ll aliquot of
sample onto an SDS-polyacrylamide gel (Laemmli, 1970) using
10% running and 4% stacking gel. The molecular mass of proteins was determined using higher range protein molecular weight mar- ker (myosin rabbit muscle 205 kDa, phosphorylase b 97.4 kDa, bovine serum albumin 66 kDa, ovalbumin 43 kDa and carbonic anhydrase 29 kDa) obtained from GeNeiTM, Bangalore, India.