Thank you for reporting, we will resolve it shortly
Q.
When the imidazole ring of Histidine is protonated, tendency of nitrogen to be protonated (proton migrates from $- COOH$) is in the order
Amines
Solution:
$\gamma (NH_2)$ In close to $COOH$, in $\beta(-NH_2)$, the lone pair of electrons Is involved in resonance, nod flie lone pair on $\alpha(- N=)$ is intact on $N$- atom.