Hello all,

I´m working on secreted glycoproteins using S.cerevisiae as a heterologous host (INVSc1 strain). Activity measurements and a tag based protein quantification assay are independent.

Now I was getting some really strange merged results: High activity, small enzyme amount as well as no activity, high amount. Both assays proved to be reliable before.

Therrefore I was wondering if proteolytic cleavage might be a factor, still enabling tag detection but interrupting enzyme activity.

I was thinking about using some protease deficient strain like BJ5465 (pep4:deletion; prb1:deletion) to have a deeper look into this potential issue.

Does somebody have some experience or suggestions in this regard? :)

Thanks in advance!

Best,

Pascal