CHONDROITIN 4-SULFATE EXHIBITS INHIBITORY EFFECT DURING CU2-MEDIATED LDL OXIDATION()

Chondroitin 4-sulphate (C4S), a basic component of the extracellular m atrix of the artery wail, inhibited copper-induced low density lipopro tein (LDL) oxidation by prolonging the lag time and reducing the rate of propagation, LDL oxidation was assessed by monitoring conjugated di enes and low level chemiluminescence, A possible initial key reaction in LDL oxidation, the reduction of copper(II) to copper(I) by LDL, was decreased in the presence of C4S. Moreover, C4S protected tryptophan residues of C4S in the early stage of LDL oxidation and during the sub sequent propagation phase, The presence of the sulphate group in posit ion 4 of N-acetylgalactosaminyl residues of C4S is crucial for protect ive activity, In Fact, the structurally related chondroitin 6-sulphate , also present in tissues, had no effect an LDH. oxidation. These data suggest that C4S mag contribute to protest LDL against oxidation in a rterial intima. (C) 1997 Federation of European Biochemical Societies.