3D structure of protein has precious informations. Proteins are the end product of the decoding process that starts with the information in cellular . Protein are also referred as workhorses of the cell in which protein compose structural and motor element in the cell, they serve as the catalysts for virtually every biochemical reaction that occurs in living things. This incredible array of function derives from a startlingly simple code that specifies a hugely diverse set of structures.
Each gene in cellular DNA contains the code for unique protein structure. These proteins assembled with different amino acid sequences, and also held together by different bonds, folded into a variety of three-dimensional structure. The folded shape or conformation depends on the linear amino acid sequence of the protein.
Proteins are made of amino acid, which are small organic molecules that consist of an central carbon atom linked to an amino group, a carboxyl group, a hydrogen atom and a variable component called a side chain. Within a protein, multiple amino acid are linked together by peptide bonds, therefore forming a long chain. The linear sequence of amino acid within protein is considered the primary structure of protein.
The primary protein structure has a linear sequence of the polypeptide chain. This type of protein structure is held together by the covalent linkages such as disulfide bonds between the amino acids and peptide bonds, thereby forming long chain. There are 20 different types of amino acids, each of which has a unique side chain. The side chains of amino acids have different features and chemistries. The largest group of amino acid have non-polar side chains. Several other amino acids have side chains with positive and negative charges while others have polar but uncharged side chains.
Each gene in cellular DNA contains the code for unique protein structure. These proteins assembled with different amino acid sequences, and also held together by different bonds, folded into a variety of three-dimensional structure. The folded shape or conformation depends on the linear amino acid sequence of the protein.
Proteins are made of amino acid, which are small organic molecules that consist of an central carbon atom linked to an amino group, a carboxyl group, a hydrogen atom and a variable component called a side chain. Within a protein, multiple amino acid are linked together by peptide bonds, therefore forming a long chain. The linear sequence of amino acid within protein is considered the primary structure of protein.
The primary protein structure has a linear sequence of the polypeptide chain. This type of protein structure is held together by the covalent linkages such as disulfide bonds between the amino acids and peptide bonds, thereby forming long chain. There are 20 different types of amino acids, each of which has a unique side chain. The side chains of amino acids have different features and chemistries. The largest group of amino acid have non-polar side chains. Several other amino acids have side chains with positive and negative charges while others have polar but uncharged side chains.
The secondary structure of a protein structure is made of alpha helix and beta sheets. The base of any protein structure is the amino acids that are linked together by peptide bonds. The structural formation of peptide group gives its characterization.Elsewhere the pattern of hydrogen bonds determines the secondary structure
The alpha helix is formed in such way that every N-H bond forms a hydrogen bond to the C=O, which forms the backbone of the secondary structure. The beta sheet is connected laterally by at least two or three back bone hydrogen bonds, forming a generally twisted, pleated sheet.
The beta sheets is compromised of anti-parallel Beta sheets and parallel Beta sheets whereby, the anti-parallel Beta sheets neighboring hydrogen bond moves in the opposite direction . The parallel Beta sheet extends its hydrogen bond in the same direction.
An example of the secondary structure is keratin. Keratin is found in our hairs and is made of the secondary protein structure.
Third type of structure found in proteins often referred as tertiary protein structure. It is a three dimensional structure of a single, double or triple bonded protein molecule. The protein molecule will bend and twist in such way as to achieve maximum stability or lowest energy state. Although, the three dimensional shape of protein may seem irregular and random because it is fashioned by many stabilized forces due to the bonding interactions between the side chain groups of the amino acids.
Many proteins are actually assemblies of more than one polypeptide chain, which in the context of the larger assemblage are known as protein subunits. In addition to the tertiary structure of the subunits, multiple-subunit proteins possess a quaternary structure, which is the arrangement into which the subunits assemble.
The quaternary protein structure involves the clustering of several individual peptide or protein chains into a final specific shape. A variety of bonding interactions including hydrogen bonding, salt bridges, and disulfide bonds hold the various chains into a particular geometry. There are two major categories of proteins with quaternary structure - fibrous and globular.
Fibrous Proteins: Actually, the final beta-pleated sheet structure of silk is the result of the interaction of many individual protein chains. Specifically, hydrogen bonding on amide groups on different chains is the basis of beta-pleated sheet in silk proteins.
Other fibrous proteins such as the keratins in wool and hair are composed of coiled alpha helical protein chains with other various coils analogous to those found in a rope. Other keratins are found in skin, fur, hair, wool, claws, nails, hooves, horns, scales, beaks, feathers, actin and mysin in muscle tissues and fibrinogen needed for blood clots.
Globular Proteins:
On the other hand, globular proteins may have a combination of the above types of structures and are mostly clumped into a shape of a ball. Major examples include insulin, hemoglobin, and most enzymes.
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