Method for determining glycosylation and terminal modification of samples during protein purification process

Abstract

The present invention provides a method for determining glycosylation and terminal modifications of immunoglobulin during immunoglobulin purification process, which can simultaneously and rapidly determine glycosylation, N-terminal pyroglutamination and C-terminal de-lysination of immunoglobulin, including Step 1) separating immunoglobulin by using cation-exchange resin, and collecting different components in according to retention time; Step 2) denaturing the components of immunoglobulin obtained in step 1) with a denaturant, followed by reducing them with a reducing agent, to separate the light chain and heavy chain; Step 3) separating the light chain and heavy chain of immunoglobulin of step 2) by using reverse phase ultrahigh pressure liquid chromatography; Step 4) measuring the molecular weights of the light chain and heavy chain obtained in step 3) with mass spectrum; and Step 5) analyzing the chromatographic data obtained in step 3) and the mass spectrometric data obtained in step 4) to determine glycosylation and terminal modifications of the immunoglobulin.