Table II.

Glucan synthase activity in E. coli soluble extracts

Plasmid-aInsertGlucan Synthase Activity
Total unitsRelative units-b
nmol Glc incorporated min−1mg−1
pET-29b(+)None2.10  ± 0.291.0
pHC5DU1C-c 10.41  ± 1.935.0
pET-32b(+)None2.88  ± 0.181.0
pHC6DU1C14.19  ± 1.604.9

Gene expression was induced for 5 h in the exponential phase ofE. coli cells transformed with the indicated plasmid. Total soluble extracts were assayed for SS activity in the presence of citrate and glycogen primer. Values indicate means ±se (n = 4).

    • F0-a pET-29b(+) and pET-32b(+) are from Novagen. pHC5 and pHC6 are based in these two vectors, respectively.

    • F0-b Total activity units obtained for the appropriate plasmid vector with no insert are assigned a value of 1.

    • F0-c DU1C, DU1 residues 1226 to 1674.