Related Experiment Video

Updated: Aug 10, 2026

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins
11:25

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins

Published on: October 4, 2017

Characterization of advanced glycation end products: mass changes in correlation to side chain modifications

Annett Schmitt1, Jovana Gasic-Milenkovic, Johannes Schmitt

  • 1Interdisciplinary Centre of Clinical Research IZKF, Faculty of Medicine, University of Leipzig, Germany. annett_schmitt@web.de

Analytical Biochemistry
|September 20, 2005
PubMed

Insights

Advanced glycation end products (AGEs) increase protein mass and absorbance as their concentration rises. This study quantifies AGE formation kinetics and mass increase in human serum albumin (HSA).

Area of Science:

  • Biochemistry
  • Proteomics
  • Chemical Biology

Background:

  • Advanced glycation end products (AGEs) are implicated in disease pathogenesis.
  • Characterizing heterogeneous AGE modifications is challenging.
  • Understanding AGE formation kinetics and structure is crucial.

Purpose of the Study:

  • To characterize AGE formation kinetics and structures.
  • To investigate the relationship between AGE formation and mass increase.
  • To analyze AGEs derived from human serum albumin (HSA) modified by glucose, methyl glyoxal, and glyoxylic acid.

Main Methods:

  • Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to determine molecular mass.
  • Quantification of lysine and arginine side chain modifications.
  • Measurement of AGE-specific absorbance and fluorescence.

Main Results:

  • Molecular mass of HSA-AGEs increased with higher modifier concentrations.
  • Mass increase correlated with AGE-specific absorbance at 360 nm.
  • Mass spectrometric data demonstrated a direct correlation between absorbance at 360 nm and mass increase during AGE formation.

Conclusions:

  • AGE formation leads to a measurable increase in protein mass.
  • Absorbance at 360 nm serves as a reliable indicator of AGE formation and associated mass increase.
  • This study provides quantitative insights into AGE formation kinetics and structural changes.

More Related Videos

Determination of Glucan Chain Length Distribution of Glycogen Using the Fluorophore-Assisted Carbohydrate Electrophoresis (FACE) Method06:13

Determination of Glucan Chain Length Distribution of Glycogen Using the Fluorophore-Assisted Carbohydrate Electrophoresis (FACE) Method

Published on: March 31, 2022

Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations05:57

Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations

Published on: April 26, 2024

Related Concept Videos

Covalently Linked Protein Regulators02:04

Covalently Linked Protein Regulators

Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
Protein Glycosylation01:25

Protein Glycosylation

Glycosylation, the most common post-translational modification for proteins, serves diverse functions. Adding sugars to proteins makes the proteins more resistant to proteolytic digestion. Glycosylated proteins can act as markers and receptors to promote cell-cell adhesion. Additionally, they have many essential quality control functions in the cell, such as correct protein folding and facilitating transport of misfolded proteins to the cytosol, which can be degraded.
Glycosylation occurs in...
Oligosaccharide Assembly01:24

Oligosaccharide Assembly

Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...
Protein Modifications in the RER01:26

Protein Modifications in the RER

Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
Protein Folding Quality Check in the RER01:29

Protein Folding Quality Check in the RER

ER is the primary site for the maturation and folding of soluble and transmembrane secretory proteins. The calnexin cycle is a specific chaperone system that folds and assesses the confirmation of N-glycosylated proteins before they can exit the ER lumen. The primary players of this quality check pipeline are the lectins, ER-resident chaperones, and a glucosyl transferase enzyme. In case the calnexin system in the lumen fails to salvage a misfolded protein, it is transported to the cytoplasm...
Proteoglycans01:05

Proteoglycans

Glycans, a class of complex heterogeneous molecules, can be covalently attached to proteins to form glycosylated proteins that regulate various physiological and pathological processes. Glycosylated proteins or glycoproteins comprise N-linked and O-linked oligosaccharides. O-glycosylation is the most common type of protein glycosylation. Here, glycans attach to the oxygen atom of the hydroxyl groups of Serine or Threonine residues. O-linked glycosylation occurs later in protein processing,...