Abstract
Large amounts of Cu in contaminated sediments can be dissolved by digestive fluids of deposit feeders during an in vitro digestion (Mayer et al. Environ. Sci. Technol. 1996, 30, 2641) and may subsequently become available to those organisms. The mechanisms of this digestive dissolution were investigated by comparing Cu release potentials of modified and unmodified gut fluids. Microwave treatments indicated that complexation rather than enzymatic action likely accounts for enhanced Cu solubilization by gut fluids rich in protein. Solutions of a common protein, bovine serum albumin, with similar AA concentrations mimicked digestive fluids in releasing sedimentary Cu. Chemical modification of histidine residues in gut fluids drastically reduced Cu release, sug gesting their important role in Cu bioavailability. Using an ion-selective electrode, we found an abundance of gut ligand sites with conditional stability constants >1010, consistent with histidine complexation. Histidine concentra tions among various ...
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call