The LC/MS analysis of glycation of IgG molecules in sucrose containing formulations.
Glycation of a recombinant monoclonal IgG2 molecule, in sucrose containing liquid formulations, was studied using reversed-phase LC/MS analysis of the intact IgG, the F(ab')2 fragments and after complete tryptic digestion. The extent of glycation in sucrose containing formulations was monitored at different temperatures over a period of 21 months using the Hexose index (Hex(I)). Hex(I) represents the average number of hexose molecules per molecule of IgG and was calculated by using the intensity values of peaks corresponding to hexose isoforms in the deconvoluted mass spectra. The rate of glycation in mildly acidic sucrose containing formulations was proportional to the incubation temperature. No glycation was observed in sucrose containing formulations incubated at 4 degrees C even after 18 months. However, when the same formulations were incubated at 37 degrees C glycation was observed after just 1 month. The glycation sites were mapped to 10 lysine residues distributed throughout the molecule. The amino terminal end of the light chain was also shown to contain glycation. The surface accessibility of the lysine side chain could influence its susceptibility to glycation.
Gadgil
Himanshu S
HS
Department of Pharmaceutics, Amgen Inc., 1201 Amgen Court West, Seattle, Washington 99119-3105, USA. hgadgil@amgen.com
Bondarenko
Pavel V
PV
Pipes
Gary
G
Rehder
Doug
D
McAuley
Arnold
A
Perico
Natalie
N
Dillon
Tom
T
Ricci
Margaret
M
Treuheit
Michael
M
D000911:Antibodies, Monoclonal / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D002853:Chromatography, Liquid; D005079:Excipients / Q000737:chemistry*; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry; D007074:Immunoglobulin G / Q000737:chemistry*; D008239:Lysine / Q000737:chemistry; D008958:Models, Molecular; D010449:Peptide Mapping; D011487:Protein Conformation; D011489:Protein Denaturation; D011994:Recombinant Proteins / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013395:Sucrose / Q000737:chemistry*; D013678:Technology, Pharmaceutical / Q000379:methods*; D013696:Temperature; D013997:Time Factors; D014357:Trypsin
D000911:Antibodies, Monoclonal; D005079:Excipients; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D013395:Sucrose; D014357:Trypsin; D008239:Lysine