Formation of a ternary complex with serum albumin: an explanation for the effect of alpha-mercapto-beta-(2-furan) acrylic acid on rat plasma zinc clearance.
1. Four, six and eight hours after gavage of rats with alpha-mercapto-beta-(2-furan)acrylic acid (MFA) (25 mg/kg) serum zinc concentration was increased ten-fold over control levels and a mean molar ratio of 1 albumin:0-4 zinc:0-8 MFA was found for seventeen sera. 2. At pH 7-5 a maximum of 1 mole of MFA could be bound per mole of metal-free bovine serum albumin. 3. In the presence of zinc ion, albumin-zinc-MFA complexes formed, since for each mole of albumin-zinc complex an additional mole of MFA could be bound to albumin. Complexes up to a molar stoichiometry of 1 albumin:2 zinc:3 MFA were prepared. 4. MFA stabilized the albumin-zinc complex against dissociation. 5. Formation of similar complexes in vivo may account for the markedly delayed clearance of plasma zinc rats administered beta-aryl derivatives of alpha-mercapto-acrylic acid.
D000179:Acrylates / Q000097:blood / Q000494:pharmacology*; D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D002614:Chelating Agents; D002850:Chromatography, Gel; D008024:Ligands; D008297:Male; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000097:blood / Q000494:pharmacology*; D013997:Time Factors; D015032:Zinc / Q000097:blood*; D015037:Zinc Radioisotopes
D000179:Acrylates; D000596:Amino Acids; D002614:Chelating Agents; D008024:Ligands; D013438:Sulfhydryl Compounds; D015037:Zinc Radioisotopes; D012710:Serum Albumin, Bovine; D015032:Zinc