Water-Soluble Near-Infrared Fluorescent Probes for Specific Detection of Monoamine Oxidase A in Living Biosystems

Abstract

Monoamine oxidase (MAO) has two isomers (A and B), and the analysis of each one in biological samples is of great potential in studying MAO-related diseases. However, specific detection and imaging of MAO-A in cells and in vivo are still a great challenge at present due to the relative lack of suitable near-infrared (NIR) fluorescent probes. In this work, two new NIR fluorescent probes, Rma-1 and Rma-2, have been developed for the analysis of MAO-A in living biosystems. The probes were designed by conjugating the specific structure of the MAO-A inhibitor to hemicyanine (an NIR fluorophore) directly or through a self-immolative linker. Both probes are water-soluble and showed selective and sensitive NIR (708 nm) responses toward MAO-A rather than MAO-B, of which probe Rma-1 with a self-immolative linker exhibited superior analytical performance with a detection limit of 4.5 ng/mL and 13-fold specificity for MAO-A over MAO-B. Further, probe Rma-1 has been successfully utilized to image the MAO-A activity in cells, zebrafish, and tumor-bearing mice, showing a promising prospect for MAO-A study in carcinoma.

Activity-based NIR fluorescent probes based on the versatile hemicyanine scaffold: design strategy, biomedical applications, and outlook

“…61). 318 Addition of MAO-A to the solution of probes resulted in significant fluorescence at 708 nm. In addition, probe Ram-1 exhibited superior analytical performance compared to probe Ram-2 due to the existence of a self-immolative linker.…”

Hemicyanine‐Based Near‐Infrared Activatable Probes for Imaging and Diagnosis of Diseases

“…Ty rosinase (TYR), ac opper-containing monooxygenase, is known to play ar ole in melanin synthesis. [83] Overexpression of TYR is ah allmark of melanoma progression. Dings laboratory developed Probe 31 and successfully applied it to detect endogenous TYR in zebrafish and xenograft mouse models with melanoma (Figure 14 i,j).…”

Recent Advances in the Fluorescent Probes for Flavinase Activity: Design and Applications

“…Ma and his group reported a class of near-infrared fluorescent probes (probes 8 and 9), which was design by MAO-A inhibitor hemicyanine fluorophore and a self-immolation linker in 2021. [21] Probes 8 and 9 can be used to selectively detect MAO-A. In the presence of MAO-A, both probes are oxidatively deaminated, and the fluorophore HXPI is released after rearrangement and elimination (as shown in Figure 3).…”

“…Ma and his group reported a class of near‐infrared fluorescent probes ( probes 8 and 9 ), which was design by MAO‐A inhibitor hemicyanine fluorophore and a self‐immolation linker in 2021 [21] . Probes 8 and 9 can be used to selectively detect MAO‐A.…”