Protein mass measurement, peptide mapping, and sequencing by mass spectrometry is the most powerful method to test for, quantify, and and localize post-translational modification of any kind, including glycation.

Hi Maria, most glycated proteins can be isolated using immobilized boronic acid:

 http://www.piercenet.com/product/boronic-acid-resin

Glycation of proteins is a non-enzymatic chemical reaction that depends on the concentration of sugars containing aldehydes (e.g. glucose),  proteins having free primary amines, pH and time.

Since our bodies mainly  rely on glucose as an energy source, there will always be protein glycation occurring within us. The more glucose you have in your blood, the more protein glycation will occur.

Diabetics have more glucose in their blood and this leads to more extensive protein glycation. 

In short, this is the cause of most diabetic complications.

Glycation of plasma proteins is always occurring, but since plasma proteins are turned over rapidly, their glycation does not pose a problem.

The problem with glycation is with extravascular proteins that have a low turnover rate, such as collagens and other ECM proteins that support capillary structures.

When these proteins are over-glycated, they can't support the capillaries and  blood flow is restricted. When you have restricted blood flow to organs, you get diabetic complications.

Protein mass measurement, peptide mapping, and sequencing by mass spectrometry is the most powerful method to test for, quantify, and and localize post-translational modification of any kind, including glycation.

Thank you everybody!!! 

Steingrimur Stefansson: Is there any possibility that glycation can slow down membrane proteins turnover? I am wondering if high levels of glucose for a long period of time can modified membrane proteins trafficking.

Hi Maria, I don't know much about the effects of membrane protein glycation and its effect on their turnover.

But many membrane proteins are turned over by ubiquitin, which is attached to lysines in proteins destined for proteasome degradation.

Since glycation modifies lysines in proteins, it is possible that the glycation can inhibit ubiquitin labeling to these lysines. 

Again, I'm just speculating here, since I don't know a lot about membrane protein glycation.

Hi Maria, just to add, if you are looking at a specific membrane protein on a cell line and assessing its turnover in the presence or absence of high levels of glucose, there is a good chance that you can show it.

If you have an antibody against you protein of interest that works in IP experiments, you can plate cells in 6-well dishes, do cell surface biotinylation, incubate them in either regular media or high glucose media and do IP of the cell lysates at various time points.

Do a western on the IPs and probe the blot with an avidin-HRP conjugate and look for a loss of signal in the cells that were not incubated with high glucose compared with the ones that were.

Thank you so much! :)

HI Maria,

In addition to Adam's answer, for characterization by MS/MS, you may have to use multiple strategies. E.g. avoiding the use of trypsin. In addition glycation will reduce the charge of the protein by 1 per glycation. In this case analysis in the analysis in the negative ion mode may be more useful if there are sufficient -COOH groups in the protein.

Regards, Anant Dave 

A bit late to the party.. But as per previous answers, the gold standard technique for quantifying AGEs is presently MS/MS. MS/MS overcomes the issues presented by antibody-based methods of AGE detection, including the inability to detect sterically hidden AGEs. http://clinchem.aaccjnls.org/content/50/7/1222.short

Nobody has addressed María's question regarding treatments or drugs to reduce AGE formation. This recent review provides nice insight into pharmaceutical drugs that target AGEs, which you could consider for use in your experiments: https://www.ncbi.nlm.nih.gov/labs/articles/27392438/ Best of luck.

Thank you so much!