Proteic structures

Aminoacid have, in general, caracteres which make with they can be arranjed in specific groups, such as hydrophobic, hydrophilous, aromatic, aliphatic,amonst, depending of their chains lateral components. One sum of characteristics, such as hydrophobicidy degree, presence of sulfur and size, determinate which kind of secondary structure and subsequently supersecondary, tertiary and quaternary; one specif aminoacid sequence will arise. Sequences containing many differences related to aminoacids, may origin similar proteins, just for keeping aminoacids with similar characteristics in analogous positions in the sequences.

Works carried out with lambda phage represser , the mutations were induced in different aminoacids, which were placed, and the functionally stable proteins were selected. Throught this works, the scients found out that great part of the positions might be modified without loose the origina funcion of protein.