The present invention relates to proteins, particularly antibodies such as anti-CD20/anti-CD3 bispecific antibodies and anti α-synuclein antibodies, having monogalactosylated (G1) and digalactosylated (G2) glycans. More particular, the present invention relates to galactosylation engineering to generate proteins with improved therapeutic properties, including proteins with increased titer. Further, the invention relates to a cell culture medium and a mammalian cell as well as methods using said cell culture medium and said mammalian cell for producing said proteins. Moreover, the present invention relates to the use of said antibodies as a medicament such as for the treatment of cancer, particularly cancer associated with B-cells, or Parkinson's disease.