Good luck.  When you make an imine with an aldehyde the principal mechanism of irreversability is that a stray reductant (available in spades in biochemical settings) takes the imine down to a primary amine.  (This is not found in most textbooks, you just have to know that).  Now, a primary amine is a relatively stable covalent bond, and getting selective deamination is going to be especially difficult since there&#x27;s plenty of amines around.  Not the least of which is the other side of the lysine that the aldehyde attached to in the first place.