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Glycosylation Profiles of the Human Colorectal Cancer A33 Antigen Naturally Expressed in the Human Colorectal Cancer Cell Line SW1222 and Expressed as Recombinant Protein in Different Insect Cell Lines
Author(s) -
Joosten Christoph E.,
Cohen Leonard S.,
Ritter Gerd,
Batt Carl A.,
Shuler Michael L.
Publication year - 2004
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp034378n
Subject(s) - glycosylation , recombinant dna , colorectal cancer , cancer , cell culture , biology , antigen , cancer research , biochemistry , immunology , gene , genetics
The A33 antigen is a cell surface glycoprotein expressed in human gastrointestinal epithelium and in 95% of colorectal cancers. We have compared the N‐linked glycosylation profile of A33 antigen naturally expressed in a human colorectal cancer cell line with recombinant human A33 antigen (rA33) produced in insect cell culture using the baculovirus expression vector. N‐Linked glycans were enzymatically released from the protein, and glycan composition was analyzed by HPLC. In three insect cell lines tested (Sf‐21, Tn5B1–4, and Tn‐4s), glycosylation of rA33 was dominated by high mannose structures (M 5 Gn 2 to M 9 Gn 2 ; 78–95% of total N‐linked glycans), with M 8 Gn 2 being the single most abundant glycoform. A33 antigen naturally expressed in the SW1222 human colon cancer cell line (A33) also possessed a high abundance of high mannose glycans (72%). No complex glycosylation was detected on rA33 expressed in insect cells. Natural A33 was galactosylated to a small extent (6%). These results illustrate a case of similar glycosylation of a glycoprotein between a recombinant version produced in insect cell culture and its counterpart naturally expressed in human cell culture.