Principles of Protein Structural Organization - G. Schulz 1982

Protein-ligand interactions
Protein interactions with other macromolecules
Conclusion

The normal functioning of living organisms is made possible only because natural Proteins do not exhibit the inherent capacity of Polypeptides to bind all types of small molecules, but instead specialize in only a few specific types. Only one type of protein, IMMUNOGLOBULINS, possesses the maximum possible number of binding sites. Therefore, a systematic analysis of immunoglobulin–Ligand systems allows us to elucidate the General Principles of Protein–ligand interactions. Furthermore, the architecture of immunoglobulins can serve as a basis for the in vitro synthesis of polypeptides with desired properties.

Living organisms contain a vast array of diverse low-molecular-weight compounds; however, the dominant role is played by a restricted group of metabolites, including Certain Amino Acids, as well as adenosine and porphyrin derivatives. Most proteins specifically interact with one or more of such metabolites. Adenosine NUCLEOTIDES and other phosphoryl-containing compounds typically bind to a specific site within the Rossmann fold.

Studies of heme-containing proteins reveal how The properties of polyfunctional chemical compounds, such as iron–porphyrin complexes, are utilized for biological Functions. The protein moiety of the molecule ensures that only a single specific reaction occurs at the heme iron atom in each case, and modifies the inherent Chemical properties of the heme under METABOLISM/18.html">The Influence of physiologically important factors.

Of greatest importance for biological processes are proteins that form complexes with lipid bilayers, saccharides, and Nucleic Acids. Some insight into these Proteins can be gained from already investigated protein–ligand interactions. To broaden our understanding in this field, data on the three-dimensional structures of such complexes are essential.

In Conclusion, immunoglobulins are the most suitable objects for studying Structure/156.html">Protein Interactions with virtually any Other Compounds. As for the interactions between proteins and the group of most critical metabolites, structural predictions applicable to the majority of proteins can already be made.