Native tertiary structure

The folding of a single polypeptide chain in three-dimensional space is referred to as its tertiary structure. As discussed in Section 6.2, all of the information needed to fold the protein into its native tertiary structure is contained within the primary structure of the peptide chain itself. With this in mind, it was disappointing to the biochemists of the 1950s when the early protein structures did not reveal the governing principles in any particular detail. It soon became apparent that the proteins knew how they were supposed to fold into tertiary... 

Minimized interaction between eluite molecules and column packing is operative in hydrophobic interaction chromatography where biological solutes are so mildly bound to a stationary phase that their delicate native tertiary structure is not spoiled. This separation of extreme mildness is also a separation of chemically differing species, i.e., separation by composition. 

Takamoto, K., He, Q., et al. (2002). Monovalent cations mediate formation of native tertiary structure of the Tetrahymena thermophila ribozyme. Nat. Struct. Biol. 9(12), 928—933. 

Both theory (CASP6 blind prediction, Fig. 5.3a) and experiment (carried out within CASP6 as well, Fig. 5.3b) give the target molecule containing five a-helices and two fi-pleated sheets (wide arrows). These secondary structure elements interact and form the unique (native) tertiary structure, which is able to perform its biological function. Both structures in atomic resolution differ by the r.m.s. equal to 2.9 A, which is a rather small deviation. 

A prerequisite for the catalytic function of an enzyme is its native tertiary structure which is determined by the number and sequence of amino acids (primary structure) forming the molecule. Favoured by hydrogen bonds, parts of the polypeptide chain exist in an a-helical or a (3-sheet structure (secondary structure). Most enzymes are globular proteins, the tertiary structure of which may be fixed by disulfide bonds between cysteine residues. A famous example is lysozyme (Fig. 20), consisting of 129 amino acids. A defined three-dimensional structure is... 

Before a protein can fimction its polypeptide chain must fold into its own native tertiary structure. ... 

The heme has a coordinated iron ion at the center that binds to oxygen. Proteins can be denatured by heat, pH, and chemicals. Denaturation causes the protein to lose its native tertiary structure. 

Column 7 Experimental basis. The method used to measure the structure or structural change, together with particular parameters and values (if detailed). Extensive data are indicated by Figure or Table . Cmj/2 is the concentration of metal (in mol 1 ) at which half the tRNA population has native tertiary structure. 

---