Low density lipoprotein is saturable by pro-oxidant copper

• Published in: FEBS letters Vol. 343; no. 3; pp. 188 - 194
• Main Authors: Gieseg, Steven P., Esterbauer, Hermann
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 02-05-1994; Elsevier
• Subjects: Adult; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Copper - metabolism; Copper binding; Copper oxidation; EDTA, ethylenedinitrilo tetraacetic acid disodium salt; Female; Free radical; Fundamental and applied biological sciences. Psychology; Humans; Kinetics; LDL, low density lipoprotein; Lipoproteins, LDL - metabolism; Lipoproteins, myelin; Low density lipoprotein; Male; PBS, phosphate buffered saline; Proteins; Reactive Oxygen Species - metabolism; LDL, low density lipoprotein; EDTA, ethylenedinitrilo tetraacetic acid disodium salt; PBS, phosphate buffered saline; Copper binding; Copper oxidation; Kinetics; Low density lipoprotein; Free radical; Lipoprotein LDL; Copper ion; Kinetic equation; Oxidation; Binding site; In vitro; Peroxidation
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(94)80553-9

The oxidative resistance of low density lipoprotein (LDL) can be experimentally described by the length of time during which no significant lipid peroxidation is observed in a pro-oxidant environment. This period of inhibited oxidation, termed the ‘lag phase’, is partially due to the radical scavenging reactions of the anti-oxidants contained in the LDL particle. We have shown that the LDL lag time decreases with increasing copper concentration, leveling out at a relatively high copper-to-LDL ratio. This behaviour demonstrates the existence of a finite number of saturable pro-oxidant copper binding sites within the LDL particle. The relationship is described by the equation, lag time = [Cu]
− ·
K ·
t
min +
t
min where the constant,
K, is the negative reciprocal of the
x-axis intercept of the graphed function, and
t
min is given by the
y-axis intercept. By this definition of the constant,
K is the amount of copper that will produce a lag time of twice
t
min, while
t
min is the minimum time a particular LDL will resist oxidation at a maximum copper concentration.