Question

In the tertiary structure of a protein under physiological conditions, which of the following amino acids is most likely to form a hydrogen bond with a carboxyl group of an asparate residue?

glutamate=

phenylalanine

lysine

glycine

proline

Answer 1

Lysine

Catbxyl group of aspartate residue will accept hydrogen atoms(contains hydrogen acceptor in side chains).so the amino acid forming hydrogen bond with this should donate hydrogen atoms. Here lysine have hydrogen donor atom in its side chain.glutamate has hydrogen acceptor so it is less likey to form hydrogen bond with aspartate.phenyl alanine, glycine, proline has no hydrogen donor or acceptor atoms in their side chains so these aminonacids also not form hydrogen bonds with aspartate.