I have a pretty basic biochemistry question but am having trouble finding the answer to it:
Normally, 1-Fluoro-2,4-dinitrobenzene (DNFB) reacts with just the amino terminus of amino acids. However, with lysine, DNFB can react in two places (at the amino terminus and to the epsilon amino group). The DNP derivative of lysine is referred to as "epsilon-DNP-lysine".
Does "epsilon-DNP-lysine" refer to a product where the DNP is bound only to the epsilon amino group (but not to the amino terminus), or does it refer to a product where DNP is bound simultaneously to the epsilon amino group and to the amino terminus?
Also, can the same thing happen with other amino acids that have an amino group in the side chain? i.e. can there be epsilon-DNP-arginine, for instance, or is this behavior unique to lysine?