TY - JOUR
T1 - Oxidation of low-density lipoprotein by hemoglobin-hemichrome
AU - Bamm, Vladimir Varlen
AU - Tsemakhovich, Vladimir Abraham
AU - Shaklai, Nurith
PY - 2003/3/1
Y1 - 2003/3/1
N2 - Hemoglobin and myoglobin are inducers of low-density lipoprotein oxidation in the presence of H2O2. The reaction of these hemoproteins with H2O2 result in a mixture of protein products known as hemichromes. The oxygen-binding hemoproteins function as peroxidases but as compared to classic heme-peroxidases have a much lower activity on small sized and a higher one on large sized substrates. A heme-globin covalent adduct, a component identified in myoglobin-hemichrome, was reported to be the cause of myoglobin peroxidase activity on low-density lipoprotein. In this study, we analyzed the function of hemoglobin-hemichrome in low-density lipoprotein oxidation. Oxidation of lipids was analyzed by formation of conjugated diene and malondialdehyde; and oxidation of Apo-B protein was analyzed by development of bityrosine fluorescence and covalently cross-linked protein. Hemoglobin-hemichrome has indeed triggered oxidation of both lipids and protein, but unlike myoglobin, hemichrome has required the presence of H2O2. In correlation to this, we found that unlike myoglobin, hemichrome formed by hemoglobin/H2O2 does not contain a globin-heme covalent adduct. Nevertheless, hemoglobin-hemichrome remains oxidatively active towards LDL, indicating that other components of the oxidatively denatured hemoglobin should be considered responsible for its hazardous activity in vascular pathology.
AB - Hemoglobin and myoglobin are inducers of low-density lipoprotein oxidation in the presence of H2O2. The reaction of these hemoproteins with H2O2 result in a mixture of protein products known as hemichromes. The oxygen-binding hemoproteins function as peroxidases but as compared to classic heme-peroxidases have a much lower activity on small sized and a higher one on large sized substrates. A heme-globin covalent adduct, a component identified in myoglobin-hemichrome, was reported to be the cause of myoglobin peroxidase activity on low-density lipoprotein. In this study, we analyzed the function of hemoglobin-hemichrome in low-density lipoprotein oxidation. Oxidation of lipids was analyzed by formation of conjugated diene and malondialdehyde; and oxidation of Apo-B protein was analyzed by development of bityrosine fluorescence and covalently cross-linked protein. Hemoglobin-hemichrome has indeed triggered oxidation of both lipids and protein, but unlike myoglobin, hemichrome has required the presence of H2O2. In correlation to this, we found that unlike myoglobin, hemichrome formed by hemoglobin/H2O2 does not contain a globin-heme covalent adduct. Nevertheless, hemoglobin-hemichrome remains oxidatively active towards LDL, indicating that other components of the oxidatively denatured hemoglobin should be considered responsible for its hazardous activity in vascular pathology.
KW - HO
KW - Hemichrome
KW - Hemoglobin
KW - LDL
KW - Myoglobin
UR - http://www.scopus.com/inward/record.url?scp=0037343655&partnerID=8YFLogxK
U2 - 10.1016/S1357-2725(02)00255-8
DO - 10.1016/S1357-2725(02)00255-8
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AN - SCOPUS:0037343655
SN - 1357-2725
VL - 35
SP - 349
EP - 358
JO - International Journal of Biochemistry and Cell Biology
JF - International Journal of Biochemistry and Cell Biology
IS - 3
ER -