Question

Which amino acid would be capable of forming h bonds with a lysine residue in a protein?

Answer 1

Lysine has an amino group in its side chain, which at neutral pH is positively charged. Further, the amino hydrogens are capable of functioning as hydrogen-bond donors. So, amino acid residues with hydrogen bond acceptors should be able to form hydrogen bonds with a lysine residue. This would include aspartic and glutamic acid, which could also interact via ionic bonding.