Question

It looks like a hydrophobic "pocket" in mdm-2 interacts with several hydrophobic amino acids in 2. p53. What does hydrophobic mean and tell why the amino acids Phe, Leu and Trp are hydrophobic (what do you need to look at to tell if it is hydrophobic or not). Why do these hydrophobic molecules interact with each other?

Answer 1

DO N- Ć-Ć-OH » Hydrophobic means :- Hydro - water phobic - fering It meens water fearing ie they lack polarity in their side chain or have little polarity for they have no way to interact with highly bolar water molecules. Phenylalanine Leucine & Tryptophan are hydro phobic amino acids because :- b o t hes single carbon attached to benzene ring So it have only 'c' & CH² in its aromatic side chain Phenylalanine so it is non-boler & hydrophobic ( No presence of og Ng sin side chain ) Hi -ċ-Ċ -OH It has isobutyl side >> chain So , it also have only ec and ch' to interact so it is water fering non- Leucine polar hydrophobic amino acid

Although it has N-H in its side chain and it should be polar , but it is still non- polar & hydrophobic because Tryptophan a) N-H group is tiny portion of large side chain b) The lone pair present on nitrogen are distrected by resonance. - We can idenitfy whether a amino acid is hydrophobic or not by :- An amino acid is bolar when there is N,Oos - present as majority factor in side chain. If we find all ec and eHoo it is a non -polar hydrophobic molecule. » Hydrophobic interaction :- It occur when non-polar substances aggregate in an aqueous solution and exclude water molecules. This is energetically favourable. Hypre So in cese interact with do hydrophobic hydrophobic pocket in mdm-2 amino acids of p53.