Immunoglobulin glycopeptides from an XXXX -producing @entity19 @entity1582 cell line and from variant cell lines.

@entity845 @entity19 @entity4823 @entity1735 @entity1582 @entity5498 @entity10986
A @entity19 @entity1582 cell line, 45.6.3, produces an @entity10986 immunoglobulin (Ig) with 2 @entity1735 attachment sites on the heavy chains. One site is in the @entity845 domain and the other in the VH region. The oligosaccharides at each site have different structures. The ratio of radioactive @entity4823 incorporated in the VH compared with the @entity845 oligosaccharide is approximately 1 to 3. In an attempt to understand this observation further, variant cell lines derived from 45.6.3 were isolated and their Ig were characterized. A ricin-resistant line, R4R1.5, has the same 2 attachment sites as the wild type, but the ratio of radioactive @entity4823 in VH compared with @entity845 was 1:1 and not 1:3 as in the wild type. This alteration is most probably due to cellular factors, since the Ig protein is unchanged. The M3.11 cell line produces an Ig with a polypeptide deletion involving the @entity5498 domain. In this Ig, a 3rd @entity1735 attachment site can be demonstrated. The percentage of radioactivity @entity4823 in the @entity845 domain compared with the total Ig is about 25% instead of 75% as in the wild type. These results suggest that the extent of glycosylation of different sites on Ig can be affected by both cellular factors and structural changes in the Ig protein.
