Abstract
Specific molecular recognition characterizes individual proteins in the mediation of many biological phenomena. Specific protein-protein interactions guide the assembly of multimeric proteins, which are generally found in cell organelles, the cytosol, and cell membranes. They govern the biological system through their cooperative and coupled functions, such as signal transduction and enzyme activation, etc. Protein-nucleic acid interactions are the origin of the complex genetic regulation of transcription, replication, translation, and recombination. Antigens are recognized by the corresponding antibodies to neutralize infections. In cellular signal transduction pathways, phosphorylation of tyrosine residues provides a key of the switching mechanism. Small ligand molecules can control the action of proteins through specific protein-ligand interactions. The ligands are directly and indirectly recognized through the hydrogen bonds, the van der Waals attractions, and the hydrophobic interactions, in addition to the non-specific electrostatic interactions. These specific interactions are observed in the complex structures, yielded from either the rigid body association or the local folding mechanism. Structural approach with the aid of bioinformatics can dissect the interactions into several structural and energetic contributions by individual contacts.
