FIG 1.
Size exclusion chromatography analysis of LeuO wt. The LeuO wt was purified under native conditions (2 mg/3 ml) and was loaded onto a Sephacryl S-200 column. (A) Calibration curve obtained by plotting the logarithms of the known molecular mass standards versus their respective Ve/Vo values. Blue dextran was used to determine the void volume (Vo) of the column (90 ml). The following protein standards are presented in the standard curve (gray diamonds) (their molecular masses, elution volumes [Ves], and Ve/Vo values are given in parentheses): β-amylase (200 kDa, 108 ml, 1.2), alcohol dehydrogenase (150 kDa, 117 ml, 1.3), albumin (66 kDa, 129 ml, 1.43), carbonic anhydrase (29 kDa, 167 ml, 1.86), and cytochrome c (12.4 kDa, 187 ml, 2.08). (B) LeuO Ve and Ve/Vo values obtained from two independent experiments and the average LeuO Ve and Ve/Vo values; the Ve value was incorporated into the standard curve (open circle in panel A). The relative molecular mass (RMM) of the LeuO wt was calculated using the equation described in Materials and Methods, and the oligomer size of LeuO was calculated as the relative molecular mass/35.7 kDa, where the latter value is the molecular mass of the LeuO monomer.