Abstract
RP-89 Connected with the increased interest in new biopharma products is the need for quality control to ensure the use of proper batches in the production of such recombinant proteins. This includes knowledge about the correct amino acid sequence as well as modifications like glycosylation, phosphorylation etc. Using a high resolution instrument is preferred here due to the heterogeneity of those samples as well as the advantage of having an exact mass on the intact compound as well as chemical or enzymatic fragments. With the possibility of running the intact proteins directly, a high-throughput analysis is possible. In this study, the maXis QTOF was applied for the LC/MS analysis of various proteins, including recombinant IgG (MW∼149 kDa) and its component light chains (MW∼24.4 kDa) as well as proteins in monomer and dimeric forms ranging from 11 up to 177 kDa. Proteins were separated with a Zorbax SBC8, Rapid Resolution Cartridge (2.1 × 30 mm, 3.5 μm) within 15 min. and directly MS analyzed. The resolution of this instrument is able to discriminate discrete changes in the glycosylation patterns of those large molecules. When the ecombinant IgG1 from Chinese Hamster Ovary (CHO) cells was further analyzed by reduction and alkylation, it was possible to measure the resulting light chains at 0.2 ppm mass accuracy. Fractions from intact e.coli protein separations were injected by infusion into the maxis. Here, various proteins of ∼11, 20.8, and 177 kDa could be mass-separated and analyzed with high mass accuracy. The data is analyzed by specially designed software modules which compare mass patterns and accuracies with expected values ensuring a fast and reliable information retrieval.