Effect of some metal ions on the activation of prothrombin

Abstract: Publisher Summary The chapter discusses the complex formation between metallic cations and proteins, peptides, and amino acids. The chemistry of complex formation describes that the nature of metal-protein complexes must vary widely with the nature of the metal, and that the proteins with their many reactive side chains have the potential capacity to bind most metals very tightly. Apart from the alkali metals, it is safe to assume that any metallic cation that finds its way into a living organism will spend an important part of its time bound to proteins before it is excreted or laid down in skeletal tissue. The chapter explores those complexes, in which the bound metal is in equilibrium with clearly defined metal ions or simple complexes in solution. The equilibrium dialysis technique has proved to be particularly useful. Chrome tanning of animal hides is the most widespread practical application of complex formation between metal and protein. The chapter presents a survey of what has been gained from the experimental studies of complex formation between proteins and metal ions in a series of reversible systems. The chapter also discusses the effect of metal ions on the stability of proteins, and their interactions with other molecules. The solubility of proteins may be pictured as determined by a balance between attractive and repulsive forces, involving, on one hand, the interaction of the protein molecules with the solvent and, on the other hand, the interaction of the protein molecules with one another. The balance of these forces determines the degree to which the protein molecules tend to disperse and surround themselves with the medium and the degree to which they tend to aggregate together and surround themselves with other protein molecules.