Pt(CN)2-4 and Au(CN)-2: potential general probes for anion-binding sites of proteins. 35Cl and 81Br nuclear-magnetic-resonance studies
Abstract
Nuclear magnetic quadrupole relaxation appears to be a general method for studying the binding of anions to proteins. This is shown by the increase in transverse quadrupole relaxation rate of 35Cl- and 81Br- in the presence of horse liver alcohol dehydrogenase, lysozyme, trypsin, alpha-chymotrypsin, human carbonic anhydrase, fructose-1,6-bisphosphate aldolase and human serum albumin. Of the many possible binding sites at the surface of a protein (e.g. positively charged amino acid side-chains) only a few account for the main part of the relaxation enhancement. This is shown by the decrease in 35Cl- and 81Br- relaxation rate on addition of functional ligands. Large, kinetically inert, complex anions like Pt(CN)2-4 and Au(CN)-2 are found to act as strong competitors towards halogen ions for the high-affinity anion binding sites of a number of proteins. Titrations with complex anions following the 35Cl- or 81Br- relaxation rates are found to be helpful in attempts to elucidate binding mechanisms. Especially, the complex anions may be useful probes for the discrimination between general and metallic anion binding sites in proteins and they also permit correlation of information from X-ray investigations of crystals with that from p...Continue Reading
References
Binding of Au(CN)2- and Pt(CN)4-2- to horse liver alcohol dehydrogenase. A 35C1NMR relaxation study.
Presence of arginine residues at the strong, hydrophobic anion binding sites of bovine serum albumin
Citations
The relation between activity and zinc and chloride binding of Escherichia coli alkaline phosphatase
Related Concepts
Related Feeds
Bacterial Cell Wall Structure (ASM)
Bacterial cell walls are made of peptidoglycan (also called murein), which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids. Here is the latest research on bacterial cell wall structures.
Bacterial Cell Wall Structure
Bacterial cell walls are made of peptidoglycan (also called murein), which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids. Here is the latest research on bacterial cell wall structures.