Buffer condition

25 mM HEPES, 100 mM NaCl, pH 8.0

Temperature (˚C)

4

4

Results

Elution volume (mL)

14.75

15.24

Estimated mass (kDa)

55.97

45.37

Mass Determination

Protein sample

PBP4*

PBP4* ΔCTD

Calculated monomeric mass(kDa) (from the sequence, using Expasy software)

~51

~41

Mass (kDa) (from DLS)

54.5 ± 1.22

35.17 ± 1.17

Mass (kDa) (from size-exclusion

chromatography)

55.97

45.37

Oligomeric state in solution

Monomeric

Monomeric