ABSTRACT
This chapter shows that intramolecular recognition between two parts of a molecule — nucleotides of the D loop and T stem — results in the specific folding of a molecule which is absolutely necessary for further interactions and functioning. Low molecular weight molecules do not induce antibody formation. Certainly, formation of such structures requires mutual recognition of the definite parts of the polypeptides participating in the complex. Recognition results in the formation of a specific complex of biopolymers and ligands. The immobilization of biopolymers with a specific affinity towards some partner permits easy separation of this partner from a complicated mixture by affinity chromatography. The chemical reactions of biopolymers which do not change the main chain of a polymer are usually referred to as chemical modification. Problems arise only with some minor components which are sometimes scarcely identified and some new modified monomers never before encountered by investigators are present.
