FIG. 2.
Investigation of the oligomeric state of E. faecalis PTC and AgDI, using gel filtration. A semilogarithmic plot of molecular mass versus elution volume (expressed as Kd [see Materials and Methods]) from the Superdex 200HR column is shown. The circles correspond to the following protein standards: cytochrome c (12.3 kDa), lactalbumin (14.2 kDa), carbonic anhydrase (29.0 kDa), ovalbumin (42.7 kDa), bovine serum albumin (66.4 kDa), the dimer of bovine serum albumin (132.9 kDa), Pyrococcus furiosus carbamate kinase (68.8 kDa), intact (97.1 kDa) and truncated (31.9 kDa) aspartokinase III of E. coli, alcohol dehydrogenase (146.8 kDa), aldolase (156.8 kDa), Thermotoga maritima N-acetyl-l-glutamate kinase (182.0 kDa), amylase (223.8 kDa), catalase (230.3 kDa), ferritin (440 kDa), and thyroglobulin (669 kDa). The triangle and square denote, respectively, the positions of elution of the peaks of E. faecalis PTC and AgDI, assuming that PTC is a trimer (sequence-deduced mass, 120,273 Da) and AgDI is a tetramer (deduced mass, 165,412 Da).