Dansyl-Tyr-Val-Gly is a substrate of peptidylglycine monooxygenase[1].
References
[1] Welch EF, Blackburn NJ, et al. Pre-Steady-State Reactivity of Peptidylglycine Monooxygenase Implicates Ascorbate in Substrate Triggering of the Active Conformer. Biochemistry. 2022 Apr 19;61(8):665-677. DOI:10.1021/acs.biochem.2c00080