Protein and lipid oxidation products in LDL incubated with glucose
| o-Tyrosine (mmol/mol) | m-Tyrosine (mmol/mol) | HODE (nmol/mg) | |
|---|---|---|---|
| LDL | 0.15 ± 0.01 | 0.11 ± 0.01 | 0.94 ± 0.02 |
| LDL + glucose | 0.25 ± 0.01* | 0.18 ± 0.01† | 1.42 ± 0.09* |
| LDL + BHT | 0.15 ± 0.01 | 0.11 ± 0.01 | 0.97 ± 0.06 |
| LDL + glucose + BHT | 0.15 ± 0.01 | 0.12 ± 0.01 | 0.94 ± 0.03 |
| LDL + copper | 0.42 ± 0.05* | 0.28 ± 0.06* | 1.85 ± 0.22* |
Data are means ± SE of 12 independent determinations. LDL (1 mg/ml) in PBS (pH 7.4) supplemented with 0.1 mmol/l EDTA was incubated for 10 days at 37°C. Where indicated, the reaction mixture was supplemented with 25 mmol/l glucose and/or 25 μmol/l BHT. For copper oxidation, LDL was incubated for 24 h in the presence of 20 μmol/l copper sulfate without EDTA. Reactions were terminated by adding 0.2 mmol/l DTPA, 300 nmol/l catalase, and 0.1 mmol/l BHT. Amino acids composition and HODE content of LDL were determined as described in research design and methods. LDL + copper was used as a positive control, and this value is based on six independent determinations. Levels of oxidized amino acids are normalized to levels of precursor amino acid (mmol/mol phenylalanine). Levels of HODE are normalized to LDL protein (nmol/mg).
* P < 0.001 and
† P < 0.01, by one-way ANOVA when compared with LDL alone.