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Updated: Jul 6, 2026
Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations
Published on: April 26, 2024
Site-specific modification of positively-charged surfaces on human serum albumin by malondialdehyde
Takeshi Ishii1, Sohei Ito, Shigenori Kumazawa
1Department of Food and Nutritional Sciences, and Global COE Program, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
Abstract:
Malondialdehyde (MDA), a lipid peroxidation product, reacts with lysine residues in proteins. Human serum albumin (HSA) is a major target of MDA-modification of serum proteins. To identify, the modification sites of HSA by MDA in vitro, MDA-treated HSA was digested with a protease and the resulting peptides were subjected to liquid chromatography-tandem mass spectrometry. We identified six peptides, which contained a N-propenal adduct at Lys136, Lys174, Lys240, Lys281, Lys525, and Lys541, and revealed that Lys525 is the most reactive residue for MDA modification. Analysis of electrostatic surface potential of a 3-D model structure of HSA indicates that Lys525 is located at the center of positively charged grooves. The results of this study indicate that the modification of proteins by lipid-derived aldehydes may be influenced by the electrostatic potential of the protein surface.
Insights
Malondialdehyde (MDA) modifies human serum albumin (HSA) proteins. Lysine 525 is identified as the most reactive site, suggesting protein charge influences aldehyde modification.
Area of Science:
- Biochemistry
- Proteomics
- Molecular Biology
Background:
- Lipid peroxidation produces malondialdehyde (MDA), a reactive aldehyde.
- MDA can modify proteins, particularly lysine residues.
- Human serum albumin (HSA) is a primary target for MDA modification in serum.
Purpose of the Study:
- To identify specific sites of malondialdehyde (MDA) modification on human serum albumin (HSA) in vitro.
- To investigate the factors influencing MDA's reactivity with HSA.
Main Methods:
- MDA-treated HSA was digested using a protease.
- Peptides were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS).
- 3-D HSA model structure was used to analyze electrostatic surface potential.
Main Results:
- Six peptides with N-propenal adducts were identified at Lys136, Lys174, Lys240, Lys281, Lys525, and Lys541.
- Lysine 525 (Lys525) was found to be the most reactive site for MDA modification.
- Lys525 is situated centrally within positively charged grooves on the HSA surface.
Conclusions:
- Protein electrostatic potential influences modification by lipid-derived aldehydes like MDA.
- Lysine 525 is a key site for MDA adduct formation on HSA.
- This study provides insights into protein damage mechanisms in oxidative stress.
