Hello,

For all i know it is well known mammalian proteins undergo extensive PTMs immediately after translation to augment protein function diversity. But expressing these proteins in bacteria - since they lack PTM adding machinery-seems quite illogical. The context in which i present my case is when PTMs have an insumountable effect on an enzyme's activity. A case in point is highly glycosylated membrane integral enzymes. So, for those who have dealt with such proteins, would you recommend a mammalian expression system?

Note: I have expressed human tyrosinase in e.coli but shows no measurable enzyme activity when L-tyrosinase substrate is used. Help me here fellow scientists.