Expert Profile

Lina Cui

Associate Professor and Graduate Coordinator

PH-MEDICINAL CHEMISTRY | COLLEGE-PHARMACY

Research Terms & Keywords

Research Terms

Medicinal Chemistry

Research Projects

Ends

Title

07-2023

Probing the role of heparanase via in situ labeling Probing the role of heparanase via in situ labeling

12-2021

Development of Diagnostic Tools for Metastatic Melanoma via Imaging of Heparanase Activity Development of Diagnostic Tools for Metastatic Melanoma via Imaging of Heparanase Activity

Publications

Technologies

Fluorogenic Probe for More Precise Detection of Cathepsin L Activity

Demonstrates Good Selectivity and High Sensitivity for the Protease Within 10 Minutes

This fluorogenic probe rapidly detects cathepsin L activity with high sensitivity and selectivity. Cathepsin L is a lysosomal protease upregulated in many diseases and forms of cancer. Proteases are involved in the development and progression of cancer; inhibiting activity of cathepsin L may slow down cancer or disease progression.1 Direct measurement of the enzyme’s activity is necessary for developing pharmacologic inhibitors and assessing clinical samples for diagnostic purposes. However, available assays have various limitations. Standard fluorogenic probes have high background fluorescence that makes it difficult to ascertain true enzyme activity. These probes also can detect homologous enzymes such as cathepsin B and V by mistake, decreasing specificity to cathepsin L.

Researchers at the University of Florida have developed a fluorogenic probe that is highly selective to cathepsin L and not homologous enzymes. The probe’s structure results in less fluorescent background signal for better sensitivity to enzyme activity. Finally, activation of this fluorescent probe by cathepsin L is rapid, producing optimal results within 10 minutes.

Application

Fluorogenic probe for rapid, selective detection of cathepsin L enzymatic activity

Advantages

Highly selective to cathepsin L activity, avoiding off-target detection of homologous enzymes in the cathepsin family
Emits less fluorescent background signal, improving cathepsin L sensitivity for more accurate measurements
Activates rapidly in the presence of cathepsin L, detecting enzymatic activity within 10 minutes

Technology

This fluorescent probe is chemically designed to favor the known substrate preferences of cathepsin L and not any of its homologous enzymes. Kinetic assays compared the responses of this probe and available probes to isolated cathepsin L, cathepsin B, and cathepsin V. The results indicate this newly synthesized probe has high selectivity to cathepsin L and low background fluorescence relative to available probes.

Ultrasensitive Fluorogenic Probe to Detect Heparanase Activity

Single-Step Fluorescence Assay Facilitates High-Throughput Screening of Heparanase Inhibitors

This fluorogenic probe tests for the presence of heparanase and facilitates rapid screening for heparanase inhibitors to aid the development of cancer therapeutics. Heparanase is an enzyme overexpressed in many carcinomas, sarcomas, hematological malignancies, and inflammatory conditions. Upregulation of heparanase expression correlates with increased tumor size, metastasis, and poor prognosis. Detecting heparanase in the body may inform cancer therapies. The cancer diagnostics market should reach $250 billion by 2026. Common heparanase assays either lack sensitivity and/or selectivity, or require multiple steps with multiple reagents, or work at unfavorable conditions.

Researchers at the University of Florida have developed an ultrasensitive and selective heparanase small-molecule fluorogenic probe. This one-step assay is sensitive only to heparanase, and its derivatives developed in the same lab allows for use with medical imaging systems such as MRI or PET scans.

Application

Ultrasensitive heparanase small molecule fluorogenic probe to detect heparanase and screen for its inhibitors

Advantages

Reliably detects heparanase, helping screen for it during the development of cancer therapeutics
High sensitivity, accurately detecting even low levels of heparanase
High selectivity, inhibiting interference from other similar biomolecules
Assay provides simple, rapid, one-step heparanase fluorescence detection

Technology

The fluorogenic heparanase probe is comprised of two easily divisible parts, a recognition unit, and a fluorophore molecule linked by a glycosidic bond to the reducing end of the recognition unit. When heparanase breaks the glycosidic bond, the probe releases the fluorophore, which produces fluorescence. This fluorescence can be seen with a fluorescence microscope or a regular plate reader. The recognition unit is a disaccharide based on heparanase’s bond cleavage patterns. An electron-withdrawing group increases fluorescence, allowing the assay to indicate heparanase activity.