Enzymes contain several subunits to maintain different biological functions. However, it remains a great challenge for specific discrimination of one subunit over another. Toward this end, the fluorescent probe TPEMA is now presented for highly specific detection of the B subunit of cytosolic creatine (CK) kinase isoenzyme (CK‐B). Owing to its aggregation‐induced emission property, TPEMA shows highly boosted emission toward CK‐B with a fast response time and very low interference from other analytes, including the M subunit of CK (CK‐M). With the aid of a Job plot assay, ITC assay and molecular dynamics simulation, it was directly confirmed that the remarkably enhanced fluorescence of TPEMA in the presence of CK‐B results from the restriction of single molecular motion in the cavity. Selective wash‐free fluorescence imaging of CK‐B in macrophages under different treatments was successfully demonstrated.

No abstract

Enzymes contain several subunits to maintain different biological functions. However, it remains a great challenge for specific discrimination of one subunit over another. Toward this end, the fluorescent probe TPEMA is now presented for highly specific detection of the B subunit of cytosolic creatine (CK) kinase isoenzyme (CK‐B). Owing to its aggregation‐induced emission property, TPEMA shows highly boosted emission toward CK‐B with a fast response time and very low interference from other analytes, including the M subunit of CK (CK‐M). With the aid of a Job plot assay, ITC assay and molecular dynamics simulation, it was directly confirmed that the remarkably enhanced fluorescence of TPEMA in the presence of CK‐B results from the restriction of single molecular motion in the cavity. Selective wash‐free fluorescence imaging of CK‐B in macrophages under different treatments was successfully demonstrated.

No abstract

SQLE (squalene epoxidase) is a cell membranebound enzyme. It is a target of fungicides and may become a new target for cancer therapy. Therefore, monitoring the content and distribution of the key enzyme in living cells is very challenging. To achieve this goal, tetraphenyl ethylene-Ter (TPE-Ter) was first designed as a new fluorescent probe to SQLE based on its active cavity. Spectral experiments discovered that SQLE/TPE-Ter shows stronger emission with fast response time and low interference from other analytes. Molecular dynamics simulation clearly confirmed the complex structure of SQLE/TPE-Ter, and the key residues contribute to restriction of TPE-Ter single-molecular motion in the cavity. TPE-Ter-specific response to SQLE is successfully demonstrated in living cells such as LO2, HepG2, and fungi. Imaging of TPE-Ter-treated fungi indicates that it can be used to rapidly assess antifungal drug susceptibility (30 min at least). The present work provides a powerful tool to detect content and distribution of SQLE in living cells.