title: The computed distribution of copper(II) and zinc(II) ions among seventeen amino acids present in human blood plasma.
abstract: The equilibrium distribution of copper(II) and zinc(II) ions among a mixture of 17 amino acids has been computed from stability-constant and blood-plasma-composition data. At pH7.4, 98% of the copper(II) in the simulated plasma solution is co-ordinated to histidine and cystine, predominantly as the mixed-ligand complexes [Cu.His.Cystine](-) and [Cu.H.His.Cystine]. Approximately half of the zinc(II) is co-ordinated to cysteine and histidine, but appreciable complex-formation occurs with most of the other amino acids. Stability constants are given for copper(II) and zinc(II) amino acid complexes, including some mixed-ligand species, at 37 degrees C and I=0.15m.
mesh_terms: D000596:Amino Acids / Q000097:blood*; D003300:Copper / Q000097:blood*; D003553:Cystine; D006639:Histidine; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009942:Organometallic Compounds; D013696:Temperature; D015032:Zinc / Q000097:blood*
chemical_list: D000596:Amino Acids; D009942:Organometallic Compounds; D003553:Cystine; D006639:Histidine; D003300:Copper; D015032:Zinc