Methods of glycoprotein analysis

A method of characterizing higher order structure of a protein, comprising:

• obtaining a first sample comprising a labeled protein in a first state, wherein the first state comprises a first level of label;
• exposing a second sample of the protein to a stressor to obtain a labeled protein in a second state, wherein the stressor comprises a second level of label, wherein the second level of label alters a higher-order structure of the protein;
• using mass spectrometry (MS) to obtain a first MS signal of the labeled protein in the first state and a second MS signal the labeled protein in the second state;
• and
• comparing the first MS signal with the second MS signal to characterize a change in the higher order structure of the protein by the stressor.