TABLE 4.

Activity of mannosyltransferases transferring the first mannosyl residue or involved in the chain elongation of O-glycans by the T. reesei host strain QM9414 and the transformants JSK00/82 and JSK00/83 overexpressing mpg1 from cultures grown for 200 h on lactose^a

Strain	Mean mannosyltransferase activity (pmol/mg of protein/2 h) ± SD
	Total incorporation (Mg2+, Mn2+)	Transfer of the first mannosyl residue (Mg2+)	Sugar chain elongation
QM9414	94 ± 3	72 ± 3	22 ± 2
JSK00/82	172 ± 4	56 ± 3	116 ± 4
JSK00/83	206 ± 4	102 ± 4	104 ± 3

^aThe data are presented as the mean ± the standard deviation from five separate cultures. The data show values for the transfer of mannosyl residues (picomoles) from GDP[¹⁴C]Man to milligrams of endogenous protein in the membrane fractions in the presence of either Mg²⁺ or Mg²⁺ followed by Mn²⁺, as well as the total amount of mannose incorporated into the protein fraction.