Carbamylation of lysine and cysteine residues and free N-termini is a nonenzymatic PTM that has been related to protein ageing. It can be artificially introduced during sample preparation with urea, thus affecting studies directed toward in vivo carbamylation. In aqueous solution, urea is in equilibrium with ammonium and isocyanate. The latter can react with primary amines of free N-termini and ε-amine groups of lysines and cysteine sulfhydryls to form carbamyl derivatives.



Type
Predefined
pKa1
None
pKa2
None
pKa3
None
NativeCharge
Loss
Gain
CHON
Deltamass
Monoisotopic
43.0058136564926
Average
43.0247847898094
UVSpec
λ
/ nm 		ε
/ M-1 cm-1
214 0
240 0
245 0
250 0
255 0
260 0
265 0
270 0
272 0
274 0
276 0
278 0
280 0
282 0
284 0
286 0
288 0
290 0
292 0
294 0
296 0
298 0
300 0
302 0
304 0
306 0
308 0
310 0
312 0
314 0
316 0
318 0
320 0
H
AA
K, C, ^
Pattern