Show simple item record

Authordc.contributor.authorCarrasco Pozo, Catalina 
Authordc.contributor.authorÁlvarez Lueje, Alejandro es_CL
Authordc.contributor.authorOlea Azar, Claudio es_CL
Authordc.contributor.authorLópez Alarcón, Camilo es_CL
Authordc.contributor.authorSpeisky Cosoy, Hernán es_CL
Admission datedc.date.accessioned2009-05-18T16:06:02Z
Available datedc.date.available2009-05-18T16:06:02Z
Publication datedc.date.issued2006-10
Cita de ítemdc.identifier.citationEXPERIMENTAL BIOLOGY AND MEDICINE Volume: 231 Issue: 9 Pages: 1569-1575en
Identifierdc.identifier.issn1535-3702
Identifierdc.identifier.urihttps://repositorio.uchile.cl/handle/2250/123872
Abstractdc.description.abstractHomocysteine (Hcys) has been implicated in various oxidative stress–related disorders. The presence of a thiol on its structure allows Hcys to exert a double-edge redox action. Depending on whether Cu2þions occur concomitantly, Hcys can either promote or prevent free radical generation and its consequences. We have addressed in vitro the interaction between Hcys and Cu2þ ions, in terms of the consequences that such interaction may have on the free radical scavenging properties of Hcys and on the redox state and redox activity of the metal. To this end, we investigated the free radical–scavenging, O2 #1;#2;-generating, and ascorbate-oxidizing properties of the interacting species by assessing the bleaching of ABTS#1;þ radicals, the reduction of O2 #1;#2;-dependent cytochrome c, and the copper-dependent oxidation of ascorbate, respectively. In addition, electron paramagnetic resonance and Cu(I)-bathocuproine formation were applied to assess the formation of paramagnetic complexes and the metal redox state. Upon a brief incubation, the Hcys/Cu2þ interaction led to a decrease in the free radical–scavenging properties of Hcys, and to a comparable loss of the thiol density. Both effects were partial and were not modified by increasing the incubation time, despite the presence of Cu2þexcess. Depending on the molar Hcys:Cu2þ ratio, the interaction resulted in the formation of mixtures that appear to contain time-stable and ascorbate-reducible Cu(II) complexes (for ratios up to 2:1), and ascorbate- and oxygen-redox–inactive Cu(I) complexes (for ratios up to 4:1). Increasing the interaction ratio beyond 4:1 was associated with the sudden appearance of an O2 #1;#2;-generating activity. The data indicate that depending on the molar ratio of interaction, Hcys and Cu2þ react to form copper complexes that can promote either antioxidant or pro-oxidant actions. We speculate that the redox activity arising from a large molar Hcys excess may partially underlie the association between hyperhomocysteinemia and a greater risk of developing oxidativerelated cardiovascular diseases.en
Patrocinadordc.description.sponsorshipThis work was supported by FONDECYT (grant 1040736).en
Lenguagedc.language.isoenen
Publisherdc.publisherSOC EXPERIMENTAL BIOLOGY MEDICINEen
Keywordsdc.subjecthomocysteineen
Títulodc.titleIn Vitro Interaction Between Homocysteine and Copper Ions: Potential Redox Implicationsen
Document typedc.typeArtículo de revista


Files in this item

Icon

This item appears in the following Collection(s)

Show simple item record