The folding of a polypeptide chain depends not okay on its amino acid sequence b
ID: 97723 • Letter: T
Question
The folding of a polypeptide chain depends not okay on its amino acid sequence but also on the nature of the solvent. Discuss the types of interactions that might occur between water molecules and the amino acid residues of the polypeptide chain. Which groups would be exposed on the exterior of the protein in contact with water and which groups would be buried in the interior of the protein? The folding of a polypeptide chain depends not okay on its amino acid sequence but also on the nature of the solvent. Discuss the types of interactions that might occur between water molecules and the amino acid residues of the polypeptide chain. Which groups would be exposed on the exterior of the protein in contact with water and which groups would be buried in the interior of the protein?Explanation / Answer
There are three forces involves between aminoacids in a polepeptide when it is not present in water. These forces are Van der wall forcess, electrostatic charges and sulphide bonds. But when polypeptide is present in water than an extra force involves between water molecule and aminoacids that is hydrogen bond. The water molecule is composed of two hydrogen atom and one oxygen atom. The electronegativity of oxygen is more than hydrogen and hence oxygen pulls electrons from hydrogen and develops partial negative charge and consequently partial positive charge develops on hydrogen atoms. Due to this polarity of water molecule the polar amino acids (for example glutamine, serine, histidine) present as side chain in polypeptide are pulled towards water molecule forming hydrogen bond and hence exposed exterior of the protein in contact with water while the non-polar aminoacid (alanine, leucine, methionine) side chains would be buried in the interior of the protein because of their hydrophobicity. Polar aminoacids contain hydrophilic functional groups which form gydrogen bond with water. For examplle serine contains -OH group which forms hydrogen bond with water. While non-polar aminoacids contain hydrophobic groups for example -CH3 in alanine.