Tertiary protein structure salt bridges

The functionalization of folded motifs is based on an understanding of secondary and tertiary structures (Fig. 2) and must take into account the relative positions of the residues, their rotamer populations and possible interactions with residues that do not form part of the site. For example, glutamic acid in position i has a strong propensity for salt-bridge formation, and thus reduced reactivity, if there is a Lys residue available i-4 in the sequence, but the probabihty is much less if the base is i-3 [60]. Fortunately, there is a wealth of structural information on the structural properties of the common amino acids from studies of natural proteins that provides considerable support for the design of new proteins. The naturally occurring amino acids have so far been used to construct reactive sites for catalysis [11-13], metal- and heme-binding sites [14,15,19,21,22] and for the site-selective functionalization of folded proteins [24,25]. 

Also important for. stabilizing a protein s tertiary structure are the formation of disulfide bridges between cysteine residues, the formation of hydrogen bonds between nearby amino acid residues, and the presence of ionic attractions, called salt bridges, bettveen positively and negatively charged sites on various amino acid side chains tvithin the protein. 

Side chains of the amino acids participate in tertiary (3°) structure, that is, they stabilize the overall conformation of the protein molecule. The forces which hold tertiary structure together include covalent (disulfide bridges) and noncovalent (hydrogen bonding, salt bridge, hydrophobic) interactions. Shapes of tertiary structure subunits can be globular or fibrous. 

Describe how disulfide bonds, hydrogen bonds, and salt bridges help hold protein molecules together in specific tertiary structures. 

Tertiary structure the way in which the polypeptide chains of a protein fold into a characteristic three-dimensional shape, stabilized by bonds between amino acids far apart in the sequence. These bonds may be strong covalent interactions such as disulfide bridges or weaker interactions involving hydrogen bonds or salt bridges. 

The tertiary structure of proteins is the three dimensional arrangement of the polypeptide chain. Tertiary structure depicts the way in which the secondary structure folds to form the three dimensional form. Different kinds of bonds or interactions are responsible for the maintenance of the tertiary structure. They include hydrophobic forces, hydrogen bonds, disulfide bonds, salt bridges, and Van der Waal forces. 

The tertiary structure describes how the secondary structural elements of a single protein chain interact with each other to fold into a three-dimensional conformation of protein molecules. Tertiary structures are stabilized via disulfide bridges, hydrogen bonding, salt bridges, and hydrophobic interactions. 

The tertiary structure of the proteins is the 3D organisation of the proteins, involving the repartition of the secondary structure units of the proteins with respect to each other. The driving force for the folding into tertiary structure is dependent on the physicochemical properties of the medium. In aqueous solutions, the hydro-phobic residues of the proteins are hidden in the core of the proteins in order to minimise contacts with water molecules. The protein tertiary structure is stabilised by hydrophobic interactions, salt bridges, hydrogen bonds and, for some proteins, disulfide bonds. 

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